xref: /openbmc/linux/drivers/ata/libata-eh.c (revision ce932d0c5589e9766e089c22c66890dfc48fbd94)
1 /*
2  *  libata-eh.c - libata error handling
3  *
4  *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
5  *    		    Please ALWAYS copy linux-ide@vger.kernel.org
6  *		    on emails.
7  *
8  *  Copyright 2006 Tejun Heo <htejun@gmail.com>
9  *
10  *
11  *  This program is free software; you can redistribute it and/or
12  *  modify it under the terms of the GNU General Public License as
13  *  published by the Free Software Foundation; either version 2, or
14  *  (at your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful,
17  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License
22  *  along with this program; see the file COPYING.  If not, write to
23  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
24  *  USA.
25  *
26  *
27  *  libata documentation is available via 'make {ps|pdf}docs',
28  *  as Documentation/DocBook/libata.*
29  *
30  *  Hardware documentation available from http://www.t13.org/ and
31  *  http://www.sata-io.org/
32  *
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/blkdev.h>
37 #include <linux/export.h>
38 #include <linux/pci.h>
39 #include <scsi/scsi.h>
40 #include <scsi/scsi_host.h>
41 #include <scsi/scsi_eh.h>
42 #include <scsi/scsi_device.h>
43 #include <scsi/scsi_cmnd.h>
44 #include <scsi/scsi_dbg.h>
45 #include "../scsi/scsi_transport_api.h"
46 
47 #include <linux/libata.h>
48 
49 #include "libata.h"
50 
51 enum {
52 	/* speed down verdicts */
53 	ATA_EH_SPDN_NCQ_OFF		= (1 << 0),
54 	ATA_EH_SPDN_SPEED_DOWN		= (1 << 1),
55 	ATA_EH_SPDN_FALLBACK_TO_PIO	= (1 << 2),
56 	ATA_EH_SPDN_KEEP_ERRORS		= (1 << 3),
57 
58 	/* error flags */
59 	ATA_EFLAG_IS_IO			= (1 << 0),
60 	ATA_EFLAG_DUBIOUS_XFER		= (1 << 1),
61 	ATA_EFLAG_OLD_ER                = (1 << 31),
62 
63 	/* error categories */
64 	ATA_ECAT_NONE			= 0,
65 	ATA_ECAT_ATA_BUS		= 1,
66 	ATA_ECAT_TOUT_HSM		= 2,
67 	ATA_ECAT_UNK_DEV		= 3,
68 	ATA_ECAT_DUBIOUS_NONE		= 4,
69 	ATA_ECAT_DUBIOUS_ATA_BUS	= 5,
70 	ATA_ECAT_DUBIOUS_TOUT_HSM	= 6,
71 	ATA_ECAT_DUBIOUS_UNK_DEV	= 7,
72 	ATA_ECAT_NR			= 8,
73 
74 	ATA_EH_CMD_DFL_TIMEOUT		=  5000,
75 
76 	/* always put at least this amount of time between resets */
77 	ATA_EH_RESET_COOL_DOWN		=  5000,
78 
79 	/* Waiting in ->prereset can never be reliable.  It's
80 	 * sometimes nice to wait there but it can't be depended upon;
81 	 * otherwise, we wouldn't be resetting.  Just give it enough
82 	 * time for most drives to spin up.
83 	 */
84 	ATA_EH_PRERESET_TIMEOUT		= 10000,
85 	ATA_EH_FASTDRAIN_INTERVAL	=  3000,
86 
87 	ATA_EH_UA_TRIES			= 5,
88 
89 	/* probe speed down parameters, see ata_eh_schedule_probe() */
90 	ATA_EH_PROBE_TRIAL_INTERVAL	= 60000,	/* 1 min */
91 	ATA_EH_PROBE_TRIALS		= 2,
92 };
93 
94 /* The following table determines how we sequence resets.  Each entry
95  * represents timeout for that try.  The first try can be soft or
96  * hardreset.  All others are hardreset if available.  In most cases
97  * the first reset w/ 10sec timeout should succeed.  Following entries
98  * are mostly for error handling, hotplug and retarded devices.
99  */
100 static const unsigned long ata_eh_reset_timeouts[] = {
101 	10000,	/* most drives spin up by 10sec */
102 	10000,	/* > 99% working drives spin up before 20sec */
103 	35000,	/* give > 30 secs of idleness for retarded devices */
104 	 5000,	/* and sweet one last chance */
105 	ULONG_MAX, /* > 1 min has elapsed, give up */
106 };
107 
108 static const unsigned long ata_eh_identify_timeouts[] = {
109 	 5000,	/* covers > 99% of successes and not too boring on failures */
110 	10000,  /* combined time till here is enough even for media access */
111 	30000,	/* for true idiots */
112 	ULONG_MAX,
113 };
114 
115 static const unsigned long ata_eh_flush_timeouts[] = {
116 	15000,	/* be generous with flush */
117 	15000,  /* ditto */
118 	30000,	/* and even more generous */
119 	ULONG_MAX,
120 };
121 
122 static const unsigned long ata_eh_other_timeouts[] = {
123 	 5000,	/* same rationale as identify timeout */
124 	10000,	/* ditto */
125 	/* but no merciful 30sec for other commands, it just isn't worth it */
126 	ULONG_MAX,
127 };
128 
129 struct ata_eh_cmd_timeout_ent {
130 	const u8		*commands;
131 	const unsigned long	*timeouts;
132 };
133 
134 /* The following table determines timeouts to use for EH internal
135  * commands.  Each table entry is a command class and matches the
136  * commands the entry applies to and the timeout table to use.
137  *
138  * On the retry after a command timed out, the next timeout value from
139  * the table is used.  If the table doesn't contain further entries,
140  * the last value is used.
141  *
142  * ehc->cmd_timeout_idx keeps track of which timeout to use per
143  * command class, so if SET_FEATURES times out on the first try, the
144  * next try will use the second timeout value only for that class.
145  */
146 #define CMDS(cmds...)	(const u8 []){ cmds, 0 }
147 static const struct ata_eh_cmd_timeout_ent
148 ata_eh_cmd_timeout_table[ATA_EH_CMD_TIMEOUT_TABLE_SIZE] = {
149 	{ .commands = CMDS(ATA_CMD_ID_ATA, ATA_CMD_ID_ATAPI),
150 	  .timeouts = ata_eh_identify_timeouts, },
151 	{ .commands = CMDS(ATA_CMD_READ_NATIVE_MAX, ATA_CMD_READ_NATIVE_MAX_EXT),
152 	  .timeouts = ata_eh_other_timeouts, },
153 	{ .commands = CMDS(ATA_CMD_SET_MAX, ATA_CMD_SET_MAX_EXT),
154 	  .timeouts = ata_eh_other_timeouts, },
155 	{ .commands = CMDS(ATA_CMD_SET_FEATURES),
156 	  .timeouts = ata_eh_other_timeouts, },
157 	{ .commands = CMDS(ATA_CMD_INIT_DEV_PARAMS),
158 	  .timeouts = ata_eh_other_timeouts, },
159 	{ .commands = CMDS(ATA_CMD_FLUSH, ATA_CMD_FLUSH_EXT),
160 	  .timeouts = ata_eh_flush_timeouts },
161 };
162 #undef CMDS
163 
164 static void __ata_port_freeze(struct ata_port *ap);
165 #ifdef CONFIG_PM
166 static void ata_eh_handle_port_suspend(struct ata_port *ap);
167 static void ata_eh_handle_port_resume(struct ata_port *ap);
168 #else /* CONFIG_PM */
169 static void ata_eh_handle_port_suspend(struct ata_port *ap)
170 { }
171 
172 static void ata_eh_handle_port_resume(struct ata_port *ap)
173 { }
174 #endif /* CONFIG_PM */
175 
176 static void __ata_ehi_pushv_desc(struct ata_eh_info *ehi, const char *fmt,
177 				 va_list args)
178 {
179 	ehi->desc_len += vscnprintf(ehi->desc + ehi->desc_len,
180 				     ATA_EH_DESC_LEN - ehi->desc_len,
181 				     fmt, args);
182 }
183 
184 /**
185  *	__ata_ehi_push_desc - push error description without adding separator
186  *	@ehi: target EHI
187  *	@fmt: printf format string
188  *
189  *	Format string according to @fmt and append it to @ehi->desc.
190  *
191  *	LOCKING:
192  *	spin_lock_irqsave(host lock)
193  */
194 void __ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
195 {
196 	va_list args;
197 
198 	va_start(args, fmt);
199 	__ata_ehi_pushv_desc(ehi, fmt, args);
200 	va_end(args);
201 }
202 
203 /**
204  *	ata_ehi_push_desc - push error description with separator
205  *	@ehi: target EHI
206  *	@fmt: printf format string
207  *
208  *	Format string according to @fmt and append it to @ehi->desc.
209  *	If @ehi->desc is not empty, ", " is added in-between.
210  *
211  *	LOCKING:
212  *	spin_lock_irqsave(host lock)
213  */
214 void ata_ehi_push_desc(struct ata_eh_info *ehi, const char *fmt, ...)
215 {
216 	va_list args;
217 
218 	if (ehi->desc_len)
219 		__ata_ehi_push_desc(ehi, ", ");
220 
221 	va_start(args, fmt);
222 	__ata_ehi_pushv_desc(ehi, fmt, args);
223 	va_end(args);
224 }
225 
226 /**
227  *	ata_ehi_clear_desc - clean error description
228  *	@ehi: target EHI
229  *
230  *	Clear @ehi->desc.
231  *
232  *	LOCKING:
233  *	spin_lock_irqsave(host lock)
234  */
235 void ata_ehi_clear_desc(struct ata_eh_info *ehi)
236 {
237 	ehi->desc[0] = '\0';
238 	ehi->desc_len = 0;
239 }
240 
241 /**
242  *	ata_port_desc - append port description
243  *	@ap: target ATA port
244  *	@fmt: printf format string
245  *
246  *	Format string according to @fmt and append it to port
247  *	description.  If port description is not empty, " " is added
248  *	in-between.  This function is to be used while initializing
249  *	ata_host.  The description is printed on host registration.
250  *
251  *	LOCKING:
252  *	None.
253  */
254 void ata_port_desc(struct ata_port *ap, const char *fmt, ...)
255 {
256 	va_list args;
257 
258 	WARN_ON(!(ap->pflags & ATA_PFLAG_INITIALIZING));
259 
260 	if (ap->link.eh_info.desc_len)
261 		__ata_ehi_push_desc(&ap->link.eh_info, " ");
262 
263 	va_start(args, fmt);
264 	__ata_ehi_pushv_desc(&ap->link.eh_info, fmt, args);
265 	va_end(args);
266 }
267 
268 #ifdef CONFIG_PCI
269 
270 /**
271  *	ata_port_pbar_desc - append PCI BAR description
272  *	@ap: target ATA port
273  *	@bar: target PCI BAR
274  *	@offset: offset into PCI BAR
275  *	@name: name of the area
276  *
277  *	If @offset is negative, this function formats a string which
278  *	contains the name, address, size and type of the BAR and
279  *	appends it to the port description.  If @offset is zero or
280  *	positive, only name and offsetted address is appended.
281  *
282  *	LOCKING:
283  *	None.
284  */
285 void ata_port_pbar_desc(struct ata_port *ap, int bar, ssize_t offset,
286 			const char *name)
287 {
288 	struct pci_dev *pdev = to_pci_dev(ap->host->dev);
289 	char *type = "";
290 	unsigned long long start, len;
291 
292 	if (pci_resource_flags(pdev, bar) & IORESOURCE_MEM)
293 		type = "m";
294 	else if (pci_resource_flags(pdev, bar) & IORESOURCE_IO)
295 		type = "i";
296 
297 	start = (unsigned long long)pci_resource_start(pdev, bar);
298 	len = (unsigned long long)pci_resource_len(pdev, bar);
299 
300 	if (offset < 0)
301 		ata_port_desc(ap, "%s %s%llu@0x%llx", name, type, len, start);
302 	else
303 		ata_port_desc(ap, "%s 0x%llx", name,
304 				start + (unsigned long long)offset);
305 }
306 
307 #endif /* CONFIG_PCI */
308 
309 static int ata_lookup_timeout_table(u8 cmd)
310 {
311 	int i;
312 
313 	for (i = 0; i < ATA_EH_CMD_TIMEOUT_TABLE_SIZE; i++) {
314 		const u8 *cur;
315 
316 		for (cur = ata_eh_cmd_timeout_table[i].commands; *cur; cur++)
317 			if (*cur == cmd)
318 				return i;
319 	}
320 
321 	return -1;
322 }
323 
324 /**
325  *	ata_internal_cmd_timeout - determine timeout for an internal command
326  *	@dev: target device
327  *	@cmd: internal command to be issued
328  *
329  *	Determine timeout for internal command @cmd for @dev.
330  *
331  *	LOCKING:
332  *	EH context.
333  *
334  *	RETURNS:
335  *	Determined timeout.
336  */
337 unsigned long ata_internal_cmd_timeout(struct ata_device *dev, u8 cmd)
338 {
339 	struct ata_eh_context *ehc = &dev->link->eh_context;
340 	int ent = ata_lookup_timeout_table(cmd);
341 	int idx;
342 
343 	if (ent < 0)
344 		return ATA_EH_CMD_DFL_TIMEOUT;
345 
346 	idx = ehc->cmd_timeout_idx[dev->devno][ent];
347 	return ata_eh_cmd_timeout_table[ent].timeouts[idx];
348 }
349 
350 /**
351  *	ata_internal_cmd_timed_out - notification for internal command timeout
352  *	@dev: target device
353  *	@cmd: internal command which timed out
354  *
355  *	Notify EH that internal command @cmd for @dev timed out.  This
356  *	function should be called only for commands whose timeouts are
357  *	determined using ata_internal_cmd_timeout().
358  *
359  *	LOCKING:
360  *	EH context.
361  */
362 void ata_internal_cmd_timed_out(struct ata_device *dev, u8 cmd)
363 {
364 	struct ata_eh_context *ehc = &dev->link->eh_context;
365 	int ent = ata_lookup_timeout_table(cmd);
366 	int idx;
367 
368 	if (ent < 0)
369 		return;
370 
371 	idx = ehc->cmd_timeout_idx[dev->devno][ent];
372 	if (ata_eh_cmd_timeout_table[ent].timeouts[idx + 1] != ULONG_MAX)
373 		ehc->cmd_timeout_idx[dev->devno][ent]++;
374 }
375 
376 static void ata_ering_record(struct ata_ering *ering, unsigned int eflags,
377 			     unsigned int err_mask)
378 {
379 	struct ata_ering_entry *ent;
380 
381 	WARN_ON(!err_mask);
382 
383 	ering->cursor++;
384 	ering->cursor %= ATA_ERING_SIZE;
385 
386 	ent = &ering->ring[ering->cursor];
387 	ent->eflags = eflags;
388 	ent->err_mask = err_mask;
389 	ent->timestamp = get_jiffies_64();
390 }
391 
392 static struct ata_ering_entry *ata_ering_top(struct ata_ering *ering)
393 {
394 	struct ata_ering_entry *ent = &ering->ring[ering->cursor];
395 
396 	if (ent->err_mask)
397 		return ent;
398 	return NULL;
399 }
400 
401 int ata_ering_map(struct ata_ering *ering,
402 		  int (*map_fn)(struct ata_ering_entry *, void *),
403 		  void *arg)
404 {
405 	int idx, rc = 0;
406 	struct ata_ering_entry *ent;
407 
408 	idx = ering->cursor;
409 	do {
410 		ent = &ering->ring[idx];
411 		if (!ent->err_mask)
412 			break;
413 		rc = map_fn(ent, arg);
414 		if (rc)
415 			break;
416 		idx = (idx - 1 + ATA_ERING_SIZE) % ATA_ERING_SIZE;
417 	} while (idx != ering->cursor);
418 
419 	return rc;
420 }
421 
422 int ata_ering_clear_cb(struct ata_ering_entry *ent, void *void_arg)
423 {
424 	ent->eflags |= ATA_EFLAG_OLD_ER;
425 	return 0;
426 }
427 
428 static void ata_ering_clear(struct ata_ering *ering)
429 {
430 	ata_ering_map(ering, ata_ering_clear_cb, NULL);
431 }
432 
433 static unsigned int ata_eh_dev_action(struct ata_device *dev)
434 {
435 	struct ata_eh_context *ehc = &dev->link->eh_context;
436 
437 	return ehc->i.action | ehc->i.dev_action[dev->devno];
438 }
439 
440 static void ata_eh_clear_action(struct ata_link *link, struct ata_device *dev,
441 				struct ata_eh_info *ehi, unsigned int action)
442 {
443 	struct ata_device *tdev;
444 
445 	if (!dev) {
446 		ehi->action &= ~action;
447 		ata_for_each_dev(tdev, link, ALL)
448 			ehi->dev_action[tdev->devno] &= ~action;
449 	} else {
450 		/* doesn't make sense for port-wide EH actions */
451 		WARN_ON(!(action & ATA_EH_PERDEV_MASK));
452 
453 		/* break ehi->action into ehi->dev_action */
454 		if (ehi->action & action) {
455 			ata_for_each_dev(tdev, link, ALL)
456 				ehi->dev_action[tdev->devno] |=
457 					ehi->action & action;
458 			ehi->action &= ~action;
459 		}
460 
461 		/* turn off the specified per-dev action */
462 		ehi->dev_action[dev->devno] &= ~action;
463 	}
464 }
465 
466 /**
467  *	ata_eh_acquire - acquire EH ownership
468  *	@ap: ATA port to acquire EH ownership for
469  *
470  *	Acquire EH ownership for @ap.  This is the basic exclusion
471  *	mechanism for ports sharing a host.  Only one port hanging off
472  *	the same host can claim the ownership of EH.
473  *
474  *	LOCKING:
475  *	EH context.
476  */
477 void ata_eh_acquire(struct ata_port *ap)
478 {
479 	mutex_lock(&ap->host->eh_mutex);
480 	WARN_ON_ONCE(ap->host->eh_owner);
481 	ap->host->eh_owner = current;
482 }
483 
484 /**
485  *	ata_eh_release - release EH ownership
486  *	@ap: ATA port to release EH ownership for
487  *
488  *	Release EH ownership for @ap if the caller.  The caller must
489  *	have acquired EH ownership using ata_eh_acquire() previously.
490  *
491  *	LOCKING:
492  *	EH context.
493  */
494 void ata_eh_release(struct ata_port *ap)
495 {
496 	WARN_ON_ONCE(ap->host->eh_owner != current);
497 	ap->host->eh_owner = NULL;
498 	mutex_unlock(&ap->host->eh_mutex);
499 }
500 
501 /**
502  *	ata_scsi_timed_out - SCSI layer time out callback
503  *	@cmd: timed out SCSI command
504  *
505  *	Handles SCSI layer timeout.  We race with normal completion of
506  *	the qc for @cmd.  If the qc is already gone, we lose and let
507  *	the scsi command finish (EH_HANDLED).  Otherwise, the qc has
508  *	timed out and EH should be invoked.  Prevent ata_qc_complete()
509  *	from finishing it by setting EH_SCHEDULED and return
510  *	EH_NOT_HANDLED.
511  *
512  *	TODO: kill this function once old EH is gone.
513  *
514  *	LOCKING:
515  *	Called from timer context
516  *
517  *	RETURNS:
518  *	EH_HANDLED or EH_NOT_HANDLED
519  */
520 enum blk_eh_timer_return ata_scsi_timed_out(struct scsi_cmnd *cmd)
521 {
522 	struct Scsi_Host *host = cmd->device->host;
523 	struct ata_port *ap = ata_shost_to_port(host);
524 	unsigned long flags;
525 	struct ata_queued_cmd *qc;
526 	enum blk_eh_timer_return ret;
527 
528 	DPRINTK("ENTER\n");
529 
530 	if (ap->ops->error_handler) {
531 		ret = BLK_EH_NOT_HANDLED;
532 		goto out;
533 	}
534 
535 	ret = BLK_EH_HANDLED;
536 	spin_lock_irqsave(ap->lock, flags);
537 	qc = ata_qc_from_tag(ap, ap->link.active_tag);
538 	if (qc) {
539 		WARN_ON(qc->scsicmd != cmd);
540 		qc->flags |= ATA_QCFLAG_EH_SCHEDULED;
541 		qc->err_mask |= AC_ERR_TIMEOUT;
542 		ret = BLK_EH_NOT_HANDLED;
543 	}
544 	spin_unlock_irqrestore(ap->lock, flags);
545 
546  out:
547 	DPRINTK("EXIT, ret=%d\n", ret);
548 	return ret;
549 }
550 
551 static void ata_eh_unload(struct ata_port *ap)
552 {
553 	struct ata_link *link;
554 	struct ata_device *dev;
555 	unsigned long flags;
556 
557 	/* Restore SControl IPM and SPD for the next driver and
558 	 * disable attached devices.
559 	 */
560 	ata_for_each_link(link, ap, PMP_FIRST) {
561 		sata_scr_write(link, SCR_CONTROL, link->saved_scontrol & 0xff0);
562 		ata_for_each_dev(dev, link, ALL)
563 			ata_dev_disable(dev);
564 	}
565 
566 	/* freeze and set UNLOADED */
567 	spin_lock_irqsave(ap->lock, flags);
568 
569 	ata_port_freeze(ap);			/* won't be thawed */
570 	ap->pflags &= ~ATA_PFLAG_EH_PENDING;	/* clear pending from freeze */
571 	ap->pflags |= ATA_PFLAG_UNLOADED;
572 
573 	spin_unlock_irqrestore(ap->lock, flags);
574 }
575 
576 /**
577  *	ata_scsi_error - SCSI layer error handler callback
578  *	@host: SCSI host on which error occurred
579  *
580  *	Handles SCSI-layer-thrown error events.
581  *
582  *	LOCKING:
583  *	Inherited from SCSI layer (none, can sleep)
584  *
585  *	RETURNS:
586  *	Zero.
587  */
588 void ata_scsi_error(struct Scsi_Host *host)
589 {
590 	struct ata_port *ap = ata_shost_to_port(host);
591 	unsigned long flags;
592 	LIST_HEAD(eh_work_q);
593 
594 	DPRINTK("ENTER\n");
595 
596 	spin_lock_irqsave(host->host_lock, flags);
597 	list_splice_init(&host->eh_cmd_q, &eh_work_q);
598 	spin_unlock_irqrestore(host->host_lock, flags);
599 
600 	ata_scsi_cmd_error_handler(host, ap, &eh_work_q);
601 
602 	/* If we timed raced normal completion and there is nothing to
603 	   recover nr_timedout == 0 why exactly are we doing error recovery ? */
604 	ata_scsi_port_error_handler(host, ap);
605 
606 	/* finish or retry handled scmd's and clean up */
607 	WARN_ON(host->host_failed || !list_empty(&eh_work_q));
608 
609 	DPRINTK("EXIT\n");
610 }
611 
612 /**
613  * ata_scsi_cmd_error_handler - error callback for a list of commands
614  * @host:	scsi host containing the port
615  * @ap:		ATA port within the host
616  * @eh_work_q:	list of commands to process
617  *
618  * process the given list of commands and return those finished to the
619  * ap->eh_done_q.  This function is the first part of the libata error
620  * handler which processes a given list of failed commands.
621  */
622 void ata_scsi_cmd_error_handler(struct Scsi_Host *host, struct ata_port *ap,
623 				struct list_head *eh_work_q)
624 {
625 	int i;
626 	unsigned long flags;
627 
628 	/* make sure sff pio task is not running */
629 	ata_sff_flush_pio_task(ap);
630 
631 	/* synchronize with host lock and sort out timeouts */
632 
633 	/* For new EH, all qcs are finished in one of three ways -
634 	 * normal completion, error completion, and SCSI timeout.
635 	 * Both completions can race against SCSI timeout.  When normal
636 	 * completion wins, the qc never reaches EH.  When error
637 	 * completion wins, the qc has ATA_QCFLAG_FAILED set.
638 	 *
639 	 * When SCSI timeout wins, things are a bit more complex.
640 	 * Normal or error completion can occur after the timeout but
641 	 * before this point.  In such cases, both types of
642 	 * completions are honored.  A scmd is determined to have
643 	 * timed out iff its associated qc is active and not failed.
644 	 */
645 	if (ap->ops->error_handler) {
646 		struct scsi_cmnd *scmd, *tmp;
647 		int nr_timedout = 0;
648 
649 		spin_lock_irqsave(ap->lock, flags);
650 
651 		/* This must occur under the ap->lock as we don't want
652 		   a polled recovery to race the real interrupt handler
653 
654 		   The lost_interrupt handler checks for any completed but
655 		   non-notified command and completes much like an IRQ handler.
656 
657 		   We then fall into the error recovery code which will treat
658 		   this as if normal completion won the race */
659 
660 		if (ap->ops->lost_interrupt)
661 			ap->ops->lost_interrupt(ap);
662 
663 		list_for_each_entry_safe(scmd, tmp, eh_work_q, eh_entry) {
664 			struct ata_queued_cmd *qc;
665 
666 			for (i = 0; i < ATA_MAX_QUEUE; i++) {
667 				qc = __ata_qc_from_tag(ap, i);
668 				if (qc->flags & ATA_QCFLAG_ACTIVE &&
669 				    qc->scsicmd == scmd)
670 					break;
671 			}
672 
673 			if (i < ATA_MAX_QUEUE) {
674 				/* the scmd has an associated qc */
675 				if (!(qc->flags & ATA_QCFLAG_FAILED)) {
676 					/* which hasn't failed yet, timeout */
677 					qc->err_mask |= AC_ERR_TIMEOUT;
678 					qc->flags |= ATA_QCFLAG_FAILED;
679 					nr_timedout++;
680 				}
681 			} else {
682 				/* Normal completion occurred after
683 				 * SCSI timeout but before this point.
684 				 * Successfully complete it.
685 				 */
686 				scmd->retries = scmd->allowed;
687 				scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
688 			}
689 		}
690 
691 		/* If we have timed out qcs.  They belong to EH from
692 		 * this point but the state of the controller is
693 		 * unknown.  Freeze the port to make sure the IRQ
694 		 * handler doesn't diddle with those qcs.  This must
695 		 * be done atomically w.r.t. setting QCFLAG_FAILED.
696 		 */
697 		if (nr_timedout)
698 			__ata_port_freeze(ap);
699 
700 		spin_unlock_irqrestore(ap->lock, flags);
701 
702 		/* initialize eh_tries */
703 		ap->eh_tries = ATA_EH_MAX_TRIES;
704 	} else
705 		spin_unlock_wait(ap->lock);
706 
707 }
708 EXPORT_SYMBOL(ata_scsi_cmd_error_handler);
709 
710 /**
711  * ata_scsi_port_error_handler - recover the port after the commands
712  * @host:	SCSI host containing the port
713  * @ap:		the ATA port
714  *
715  * Handle the recovery of the port @ap after all the commands
716  * have been recovered.
717  */
718 void ata_scsi_port_error_handler(struct Scsi_Host *host, struct ata_port *ap)
719 {
720 	unsigned long flags;
721 
722 	/* invoke error handler */
723 	if (ap->ops->error_handler) {
724 		struct ata_link *link;
725 
726 		/* acquire EH ownership */
727 		ata_eh_acquire(ap);
728  repeat:
729 		/* kill fast drain timer */
730 		del_timer_sync(&ap->fastdrain_timer);
731 
732 		/* process port resume request */
733 		ata_eh_handle_port_resume(ap);
734 
735 		/* fetch & clear EH info */
736 		spin_lock_irqsave(ap->lock, flags);
737 
738 		ata_for_each_link(link, ap, HOST_FIRST) {
739 			struct ata_eh_context *ehc = &link->eh_context;
740 			struct ata_device *dev;
741 
742 			memset(&link->eh_context, 0, sizeof(link->eh_context));
743 			link->eh_context.i = link->eh_info;
744 			memset(&link->eh_info, 0, sizeof(link->eh_info));
745 
746 			ata_for_each_dev(dev, link, ENABLED) {
747 				int devno = dev->devno;
748 
749 				ehc->saved_xfer_mode[devno] = dev->xfer_mode;
750 				if (ata_ncq_enabled(dev))
751 					ehc->saved_ncq_enabled |= 1 << devno;
752 			}
753 		}
754 
755 		ap->pflags |= ATA_PFLAG_EH_IN_PROGRESS;
756 		ap->pflags &= ~ATA_PFLAG_EH_PENDING;
757 		ap->excl_link = NULL;	/* don't maintain exclusion over EH */
758 
759 		spin_unlock_irqrestore(ap->lock, flags);
760 
761 		/* invoke EH, skip if unloading or suspended */
762 		if (!(ap->pflags & (ATA_PFLAG_UNLOADING | ATA_PFLAG_SUSPENDED)))
763 			ap->ops->error_handler(ap);
764 		else {
765 			/* if unloading, commence suicide */
766 			if ((ap->pflags & ATA_PFLAG_UNLOADING) &&
767 			    !(ap->pflags & ATA_PFLAG_UNLOADED))
768 				ata_eh_unload(ap);
769 			ata_eh_finish(ap);
770 		}
771 
772 		/* process port suspend request */
773 		ata_eh_handle_port_suspend(ap);
774 
775 		/* Exception might have happened after ->error_handler
776 		 * recovered the port but before this point.  Repeat
777 		 * EH in such case.
778 		 */
779 		spin_lock_irqsave(ap->lock, flags);
780 
781 		if (ap->pflags & ATA_PFLAG_EH_PENDING) {
782 			if (--ap->eh_tries) {
783 				spin_unlock_irqrestore(ap->lock, flags);
784 				goto repeat;
785 			}
786 			ata_port_err(ap,
787 				     "EH pending after %d tries, giving up\n",
788 				     ATA_EH_MAX_TRIES);
789 			ap->pflags &= ~ATA_PFLAG_EH_PENDING;
790 		}
791 
792 		/* this run is complete, make sure EH info is clear */
793 		ata_for_each_link(link, ap, HOST_FIRST)
794 			memset(&link->eh_info, 0, sizeof(link->eh_info));
795 
796 		/* Clear host_eh_scheduled while holding ap->lock such
797 		 * that if exception occurs after this point but
798 		 * before EH completion, SCSI midlayer will
799 		 * re-initiate EH.
800 		 */
801 		host->host_eh_scheduled = 0;
802 
803 		spin_unlock_irqrestore(ap->lock, flags);
804 		ata_eh_release(ap);
805 	} else {
806 		WARN_ON(ata_qc_from_tag(ap, ap->link.active_tag) == NULL);
807 		ap->ops->eng_timeout(ap);
808 	}
809 
810 	scsi_eh_flush_done_q(&ap->eh_done_q);
811 
812 	/* clean up */
813 	spin_lock_irqsave(ap->lock, flags);
814 
815 	if (ap->pflags & ATA_PFLAG_LOADING)
816 		ap->pflags &= ~ATA_PFLAG_LOADING;
817 	else if (ap->pflags & ATA_PFLAG_SCSI_HOTPLUG)
818 		schedule_delayed_work(&ap->hotplug_task, 0);
819 
820 	if (ap->pflags & ATA_PFLAG_RECOVERED)
821 		ata_port_info(ap, "EH complete\n");
822 
823 	ap->pflags &= ~(ATA_PFLAG_SCSI_HOTPLUG | ATA_PFLAG_RECOVERED);
824 
825 	/* tell wait_eh that we're done */
826 	ap->pflags &= ~ATA_PFLAG_EH_IN_PROGRESS;
827 	wake_up_all(&ap->eh_wait_q);
828 
829 	spin_unlock_irqrestore(ap->lock, flags);
830 }
831 EXPORT_SYMBOL_GPL(ata_scsi_port_error_handler);
832 
833 /**
834  *	ata_port_wait_eh - Wait for the currently pending EH to complete
835  *	@ap: Port to wait EH for
836  *
837  *	Wait until the currently pending EH is complete.
838  *
839  *	LOCKING:
840  *	Kernel thread context (may sleep).
841  */
842 void ata_port_wait_eh(struct ata_port *ap)
843 {
844 	unsigned long flags;
845 	DEFINE_WAIT(wait);
846 
847  retry:
848 	spin_lock_irqsave(ap->lock, flags);
849 
850 	while (ap->pflags & (ATA_PFLAG_EH_PENDING | ATA_PFLAG_EH_IN_PROGRESS)) {
851 		prepare_to_wait(&ap->eh_wait_q, &wait, TASK_UNINTERRUPTIBLE);
852 		spin_unlock_irqrestore(ap->lock, flags);
853 		schedule();
854 		spin_lock_irqsave(ap->lock, flags);
855 	}
856 	finish_wait(&ap->eh_wait_q, &wait);
857 
858 	spin_unlock_irqrestore(ap->lock, flags);
859 
860 	/* make sure SCSI EH is complete */
861 	if (scsi_host_in_recovery(ap->scsi_host)) {
862 		ata_msleep(ap, 10);
863 		goto retry;
864 	}
865 }
866 EXPORT_SYMBOL_GPL(ata_port_wait_eh);
867 
868 static int ata_eh_nr_in_flight(struct ata_port *ap)
869 {
870 	unsigned int tag;
871 	int nr = 0;
872 
873 	/* count only non-internal commands */
874 	for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++)
875 		if (ata_qc_from_tag(ap, tag))
876 			nr++;
877 
878 	return nr;
879 }
880 
881 void ata_eh_fastdrain_timerfn(unsigned long arg)
882 {
883 	struct ata_port *ap = (void *)arg;
884 	unsigned long flags;
885 	int cnt;
886 
887 	spin_lock_irqsave(ap->lock, flags);
888 
889 	cnt = ata_eh_nr_in_flight(ap);
890 
891 	/* are we done? */
892 	if (!cnt)
893 		goto out_unlock;
894 
895 	if (cnt == ap->fastdrain_cnt) {
896 		unsigned int tag;
897 
898 		/* No progress during the last interval, tag all
899 		 * in-flight qcs as timed out and freeze the port.
900 		 */
901 		for (tag = 0; tag < ATA_MAX_QUEUE - 1; tag++) {
902 			struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
903 			if (qc)
904 				qc->err_mask |= AC_ERR_TIMEOUT;
905 		}
906 
907 		ata_port_freeze(ap);
908 	} else {
909 		/* some qcs have finished, give it another chance */
910 		ap->fastdrain_cnt = cnt;
911 		ap->fastdrain_timer.expires =
912 			ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
913 		add_timer(&ap->fastdrain_timer);
914 	}
915 
916  out_unlock:
917 	spin_unlock_irqrestore(ap->lock, flags);
918 }
919 
920 /**
921  *	ata_eh_set_pending - set ATA_PFLAG_EH_PENDING and activate fast drain
922  *	@ap: target ATA port
923  *	@fastdrain: activate fast drain
924  *
925  *	Set ATA_PFLAG_EH_PENDING and activate fast drain if @fastdrain
926  *	is non-zero and EH wasn't pending before.  Fast drain ensures
927  *	that EH kicks in in timely manner.
928  *
929  *	LOCKING:
930  *	spin_lock_irqsave(host lock)
931  */
932 static void ata_eh_set_pending(struct ata_port *ap, int fastdrain)
933 {
934 	int cnt;
935 
936 	/* already scheduled? */
937 	if (ap->pflags & ATA_PFLAG_EH_PENDING)
938 		return;
939 
940 	ap->pflags |= ATA_PFLAG_EH_PENDING;
941 
942 	if (!fastdrain)
943 		return;
944 
945 	/* do we have in-flight qcs? */
946 	cnt = ata_eh_nr_in_flight(ap);
947 	if (!cnt)
948 		return;
949 
950 	/* activate fast drain */
951 	ap->fastdrain_cnt = cnt;
952 	ap->fastdrain_timer.expires =
953 		ata_deadline(jiffies, ATA_EH_FASTDRAIN_INTERVAL);
954 	add_timer(&ap->fastdrain_timer);
955 }
956 
957 /**
958  *	ata_qc_schedule_eh - schedule qc for error handling
959  *	@qc: command to schedule error handling for
960  *
961  *	Schedule error handling for @qc.  EH will kick in as soon as
962  *	other commands are drained.
963  *
964  *	LOCKING:
965  *	spin_lock_irqsave(host lock)
966  */
967 void ata_qc_schedule_eh(struct ata_queued_cmd *qc)
968 {
969 	struct ata_port *ap = qc->ap;
970 	struct request_queue *q = qc->scsicmd->device->request_queue;
971 	unsigned long flags;
972 
973 	WARN_ON(!ap->ops->error_handler);
974 
975 	qc->flags |= ATA_QCFLAG_FAILED;
976 	ata_eh_set_pending(ap, 1);
977 
978 	/* The following will fail if timeout has already expired.
979 	 * ata_scsi_error() takes care of such scmds on EH entry.
980 	 * Note that ATA_QCFLAG_FAILED is unconditionally set after
981 	 * this function completes.
982 	 */
983 	spin_lock_irqsave(q->queue_lock, flags);
984 	blk_abort_request(qc->scsicmd->request);
985 	spin_unlock_irqrestore(q->queue_lock, flags);
986 }
987 
988 /**
989  *	ata_port_schedule_eh - schedule error handling without a qc
990  *	@ap: ATA port to schedule EH for
991  *
992  *	Schedule error handling for @ap.  EH will kick in as soon as
993  *	all commands are drained.
994  *
995  *	LOCKING:
996  *	spin_lock_irqsave(host lock)
997  */
998 void ata_port_schedule_eh(struct ata_port *ap)
999 {
1000 	WARN_ON(!ap->ops->error_handler);
1001 
1002 	if (ap->pflags & ATA_PFLAG_INITIALIZING)
1003 		return;
1004 
1005 	ata_eh_set_pending(ap, 1);
1006 	scsi_schedule_eh(ap->scsi_host);
1007 
1008 	DPRINTK("port EH scheduled\n");
1009 }
1010 
1011 static int ata_do_link_abort(struct ata_port *ap, struct ata_link *link)
1012 {
1013 	int tag, nr_aborted = 0;
1014 
1015 	WARN_ON(!ap->ops->error_handler);
1016 
1017 	/* we're gonna abort all commands, no need for fast drain */
1018 	ata_eh_set_pending(ap, 0);
1019 
1020 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
1021 		struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);
1022 
1023 		if (qc && (!link || qc->dev->link == link)) {
1024 			qc->flags |= ATA_QCFLAG_FAILED;
1025 			ata_qc_complete(qc);
1026 			nr_aborted++;
1027 		}
1028 	}
1029 
1030 	if (!nr_aborted)
1031 		ata_port_schedule_eh(ap);
1032 
1033 	return nr_aborted;
1034 }
1035 
1036 /**
1037  *	ata_link_abort - abort all qc's on the link
1038  *	@link: ATA link to abort qc's for
1039  *
1040  *	Abort all active qc's active on @link and schedule EH.
1041  *
1042  *	LOCKING:
1043  *	spin_lock_irqsave(host lock)
1044  *
1045  *	RETURNS:
1046  *	Number of aborted qc's.
1047  */
1048 int ata_link_abort(struct ata_link *link)
1049 {
1050 	return ata_do_link_abort(link->ap, link);
1051 }
1052 
1053 /**
1054  *	ata_port_abort - abort all qc's on the port
1055  *	@ap: ATA port to abort qc's for
1056  *
1057  *	Abort all active qc's of @ap and schedule EH.
1058  *
1059  *	LOCKING:
1060  *	spin_lock_irqsave(host_set lock)
1061  *
1062  *	RETURNS:
1063  *	Number of aborted qc's.
1064  */
1065 int ata_port_abort(struct ata_port *ap)
1066 {
1067 	return ata_do_link_abort(ap, NULL);
1068 }
1069 
1070 /**
1071  *	__ata_port_freeze - freeze port
1072  *	@ap: ATA port to freeze
1073  *
1074  *	This function is called when HSM violation or some other
1075  *	condition disrupts normal operation of the port.  Frozen port
1076  *	is not allowed to perform any operation until the port is
1077  *	thawed, which usually follows a successful reset.
1078  *
1079  *	ap->ops->freeze() callback can be used for freezing the port
1080  *	hardware-wise (e.g. mask interrupt and stop DMA engine).  If a
1081  *	port cannot be frozen hardware-wise, the interrupt handler
1082  *	must ack and clear interrupts unconditionally while the port
1083  *	is frozen.
1084  *
1085  *	LOCKING:
1086  *	spin_lock_irqsave(host lock)
1087  */
1088 static void __ata_port_freeze(struct ata_port *ap)
1089 {
1090 	WARN_ON(!ap->ops->error_handler);
1091 
1092 	if (ap->ops->freeze)
1093 		ap->ops->freeze(ap);
1094 
1095 	ap->pflags |= ATA_PFLAG_FROZEN;
1096 
1097 	DPRINTK("ata%u port frozen\n", ap->print_id);
1098 }
1099 
1100 /**
1101  *	ata_port_freeze - abort & freeze port
1102  *	@ap: ATA port to freeze
1103  *
1104  *	Abort and freeze @ap.  The freeze operation must be called
1105  *	first, because some hardware requires special operations
1106  *	before the taskfile registers are accessible.
1107  *
1108  *	LOCKING:
1109  *	spin_lock_irqsave(host lock)
1110  *
1111  *	RETURNS:
1112  *	Number of aborted commands.
1113  */
1114 int ata_port_freeze(struct ata_port *ap)
1115 {
1116 	int nr_aborted;
1117 
1118 	WARN_ON(!ap->ops->error_handler);
1119 
1120 	__ata_port_freeze(ap);
1121 	nr_aborted = ata_port_abort(ap);
1122 
1123 	return nr_aborted;
1124 }
1125 
1126 /**
1127  *	sata_async_notification - SATA async notification handler
1128  *	@ap: ATA port where async notification is received
1129  *
1130  *	Handler to be called when async notification via SDB FIS is
1131  *	received.  This function schedules EH if necessary.
1132  *
1133  *	LOCKING:
1134  *	spin_lock_irqsave(host lock)
1135  *
1136  *	RETURNS:
1137  *	1 if EH is scheduled, 0 otherwise.
1138  */
1139 int sata_async_notification(struct ata_port *ap)
1140 {
1141 	u32 sntf;
1142 	int rc;
1143 
1144 	if (!(ap->flags & ATA_FLAG_AN))
1145 		return 0;
1146 
1147 	rc = sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf);
1148 	if (rc == 0)
1149 		sata_scr_write(&ap->link, SCR_NOTIFICATION, sntf);
1150 
1151 	if (!sata_pmp_attached(ap) || rc) {
1152 		/* PMP is not attached or SNTF is not available */
1153 		if (!sata_pmp_attached(ap)) {
1154 			/* PMP is not attached.  Check whether ATAPI
1155 			 * AN is configured.  If so, notify media
1156 			 * change.
1157 			 */
1158 			struct ata_device *dev = ap->link.device;
1159 
1160 			if ((dev->class == ATA_DEV_ATAPI) &&
1161 			    (dev->flags & ATA_DFLAG_AN))
1162 				ata_scsi_media_change_notify(dev);
1163 			return 0;
1164 		} else {
1165 			/* PMP is attached but SNTF is not available.
1166 			 * ATAPI async media change notification is
1167 			 * not used.  The PMP must be reporting PHY
1168 			 * status change, schedule EH.
1169 			 */
1170 			ata_port_schedule_eh(ap);
1171 			return 1;
1172 		}
1173 	} else {
1174 		/* PMP is attached and SNTF is available */
1175 		struct ata_link *link;
1176 
1177 		/* check and notify ATAPI AN */
1178 		ata_for_each_link(link, ap, EDGE) {
1179 			if (!(sntf & (1 << link->pmp)))
1180 				continue;
1181 
1182 			if ((link->device->class == ATA_DEV_ATAPI) &&
1183 			    (link->device->flags & ATA_DFLAG_AN))
1184 				ata_scsi_media_change_notify(link->device);
1185 		}
1186 
1187 		/* If PMP is reporting that PHY status of some
1188 		 * downstream ports has changed, schedule EH.
1189 		 */
1190 		if (sntf & (1 << SATA_PMP_CTRL_PORT)) {
1191 			ata_port_schedule_eh(ap);
1192 			return 1;
1193 		}
1194 
1195 		return 0;
1196 	}
1197 }
1198 
1199 /**
1200  *	ata_eh_freeze_port - EH helper to freeze port
1201  *	@ap: ATA port to freeze
1202  *
1203  *	Freeze @ap.
1204  *
1205  *	LOCKING:
1206  *	None.
1207  */
1208 void ata_eh_freeze_port(struct ata_port *ap)
1209 {
1210 	unsigned long flags;
1211 
1212 	if (!ap->ops->error_handler)
1213 		return;
1214 
1215 	spin_lock_irqsave(ap->lock, flags);
1216 	__ata_port_freeze(ap);
1217 	spin_unlock_irqrestore(ap->lock, flags);
1218 }
1219 
1220 /**
1221  *	ata_port_thaw_port - EH helper to thaw port
1222  *	@ap: ATA port to thaw
1223  *
1224  *	Thaw frozen port @ap.
1225  *
1226  *	LOCKING:
1227  *	None.
1228  */
1229 void ata_eh_thaw_port(struct ata_port *ap)
1230 {
1231 	unsigned long flags;
1232 
1233 	if (!ap->ops->error_handler)
1234 		return;
1235 
1236 	spin_lock_irqsave(ap->lock, flags);
1237 
1238 	ap->pflags &= ~ATA_PFLAG_FROZEN;
1239 
1240 	if (ap->ops->thaw)
1241 		ap->ops->thaw(ap);
1242 
1243 	spin_unlock_irqrestore(ap->lock, flags);
1244 
1245 	DPRINTK("ata%u port thawed\n", ap->print_id);
1246 }
1247 
1248 static void ata_eh_scsidone(struct scsi_cmnd *scmd)
1249 {
1250 	/* nada */
1251 }
1252 
1253 static void __ata_eh_qc_complete(struct ata_queued_cmd *qc)
1254 {
1255 	struct ata_port *ap = qc->ap;
1256 	struct scsi_cmnd *scmd = qc->scsicmd;
1257 	unsigned long flags;
1258 
1259 	spin_lock_irqsave(ap->lock, flags);
1260 	qc->scsidone = ata_eh_scsidone;
1261 	__ata_qc_complete(qc);
1262 	WARN_ON(ata_tag_valid(qc->tag));
1263 	spin_unlock_irqrestore(ap->lock, flags);
1264 
1265 	scsi_eh_finish_cmd(scmd, &ap->eh_done_q);
1266 }
1267 
1268 /**
1269  *	ata_eh_qc_complete - Complete an active ATA command from EH
1270  *	@qc: Command to complete
1271  *
1272  *	Indicate to the mid and upper layers that an ATA command has
1273  *	completed.  To be used from EH.
1274  */
1275 void ata_eh_qc_complete(struct ata_queued_cmd *qc)
1276 {
1277 	struct scsi_cmnd *scmd = qc->scsicmd;
1278 	scmd->retries = scmd->allowed;
1279 	__ata_eh_qc_complete(qc);
1280 }
1281 
1282 /**
1283  *	ata_eh_qc_retry - Tell midlayer to retry an ATA command after EH
1284  *	@qc: Command to retry
1285  *
1286  *	Indicate to the mid and upper layers that an ATA command
1287  *	should be retried.  To be used from EH.
1288  *
1289  *	SCSI midlayer limits the number of retries to scmd->allowed.
1290  *	scmd->retries is decremented for commands which get retried
1291  *	due to unrelated failures (qc->err_mask is zero).
1292  */
1293 void ata_eh_qc_retry(struct ata_queued_cmd *qc)
1294 {
1295 	struct scsi_cmnd *scmd = qc->scsicmd;
1296 	if (!qc->err_mask && scmd->retries)
1297 		scmd->retries--;
1298 	__ata_eh_qc_complete(qc);
1299 }
1300 
1301 /**
1302  *	ata_dev_disable - disable ATA device
1303  *	@dev: ATA device to disable
1304  *
1305  *	Disable @dev.
1306  *
1307  *	Locking:
1308  *	EH context.
1309  */
1310 void ata_dev_disable(struct ata_device *dev)
1311 {
1312 	if (!ata_dev_enabled(dev))
1313 		return;
1314 
1315 	if (ata_msg_drv(dev->link->ap))
1316 		ata_dev_warn(dev, "disabled\n");
1317 	ata_acpi_on_disable(dev);
1318 	ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 | ATA_DNXFER_QUIET);
1319 	dev->class++;
1320 
1321 	/* From now till the next successful probe, ering is used to
1322 	 * track probe failures.  Clear accumulated device error info.
1323 	 */
1324 	ata_ering_clear(&dev->ering);
1325 }
1326 
1327 /**
1328  *	ata_eh_detach_dev - detach ATA device
1329  *	@dev: ATA device to detach
1330  *
1331  *	Detach @dev.
1332  *
1333  *	LOCKING:
1334  *	None.
1335  */
1336 void ata_eh_detach_dev(struct ata_device *dev)
1337 {
1338 	struct ata_link *link = dev->link;
1339 	struct ata_port *ap = link->ap;
1340 	struct ata_eh_context *ehc = &link->eh_context;
1341 	unsigned long flags;
1342 
1343 	ata_dev_disable(dev);
1344 
1345 	spin_lock_irqsave(ap->lock, flags);
1346 
1347 	dev->flags &= ~ATA_DFLAG_DETACH;
1348 
1349 	if (ata_scsi_offline_dev(dev)) {
1350 		dev->flags |= ATA_DFLAG_DETACHED;
1351 		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
1352 	}
1353 
1354 	/* clear per-dev EH info */
1355 	ata_eh_clear_action(link, dev, &link->eh_info, ATA_EH_PERDEV_MASK);
1356 	ata_eh_clear_action(link, dev, &link->eh_context.i, ATA_EH_PERDEV_MASK);
1357 	ehc->saved_xfer_mode[dev->devno] = 0;
1358 	ehc->saved_ncq_enabled &= ~(1 << dev->devno);
1359 
1360 	spin_unlock_irqrestore(ap->lock, flags);
1361 }
1362 
1363 /**
1364  *	ata_eh_about_to_do - about to perform eh_action
1365  *	@link: target ATA link
1366  *	@dev: target ATA dev for per-dev action (can be NULL)
1367  *	@action: action about to be performed
1368  *
1369  *	Called just before performing EH actions to clear related bits
1370  *	in @link->eh_info such that eh actions are not unnecessarily
1371  *	repeated.
1372  *
1373  *	LOCKING:
1374  *	None.
1375  */
1376 void ata_eh_about_to_do(struct ata_link *link, struct ata_device *dev,
1377 			unsigned int action)
1378 {
1379 	struct ata_port *ap = link->ap;
1380 	struct ata_eh_info *ehi = &link->eh_info;
1381 	struct ata_eh_context *ehc = &link->eh_context;
1382 	unsigned long flags;
1383 
1384 	spin_lock_irqsave(ap->lock, flags);
1385 
1386 	ata_eh_clear_action(link, dev, ehi, action);
1387 
1388 	/* About to take EH action, set RECOVERED.  Ignore actions on
1389 	 * slave links as master will do them again.
1390 	 */
1391 	if (!(ehc->i.flags & ATA_EHI_QUIET) && link != ap->slave_link)
1392 		ap->pflags |= ATA_PFLAG_RECOVERED;
1393 
1394 	spin_unlock_irqrestore(ap->lock, flags);
1395 }
1396 
1397 /**
1398  *	ata_eh_done - EH action complete
1399 *	@ap: target ATA port
1400  *	@dev: target ATA dev for per-dev action (can be NULL)
1401  *	@action: action just completed
1402  *
1403  *	Called right after performing EH actions to clear related bits
1404  *	in @link->eh_context.
1405  *
1406  *	LOCKING:
1407  *	None.
1408  */
1409 void ata_eh_done(struct ata_link *link, struct ata_device *dev,
1410 		 unsigned int action)
1411 {
1412 	struct ata_eh_context *ehc = &link->eh_context;
1413 
1414 	ata_eh_clear_action(link, dev, &ehc->i, action);
1415 }
1416 
1417 /**
1418  *	ata_err_string - convert err_mask to descriptive string
1419  *	@err_mask: error mask to convert to string
1420  *
1421  *	Convert @err_mask to descriptive string.  Errors are
1422  *	prioritized according to severity and only the most severe
1423  *	error is reported.
1424  *
1425  *	LOCKING:
1426  *	None.
1427  *
1428  *	RETURNS:
1429  *	Descriptive string for @err_mask
1430  */
1431 static const char *ata_err_string(unsigned int err_mask)
1432 {
1433 	if (err_mask & AC_ERR_HOST_BUS)
1434 		return "host bus error";
1435 	if (err_mask & AC_ERR_ATA_BUS)
1436 		return "ATA bus error";
1437 	if (err_mask & AC_ERR_TIMEOUT)
1438 		return "timeout";
1439 	if (err_mask & AC_ERR_HSM)
1440 		return "HSM violation";
1441 	if (err_mask & AC_ERR_SYSTEM)
1442 		return "internal error";
1443 	if (err_mask & AC_ERR_MEDIA)
1444 		return "media error";
1445 	if (err_mask & AC_ERR_INVALID)
1446 		return "invalid argument";
1447 	if (err_mask & AC_ERR_DEV)
1448 		return "device error";
1449 	return "unknown error";
1450 }
1451 
1452 /**
1453  *	ata_read_log_page - read a specific log page
1454  *	@dev: target device
1455  *	@page: page to read
1456  *	@buf: buffer to store read page
1457  *	@sectors: number of sectors to read
1458  *
1459  *	Read log page using READ_LOG_EXT command.
1460  *
1461  *	LOCKING:
1462  *	Kernel thread context (may sleep).
1463  *
1464  *	RETURNS:
1465  *	0 on success, AC_ERR_* mask otherwise.
1466  */
1467 static unsigned int ata_read_log_page(struct ata_device *dev,
1468 				      u8 page, void *buf, unsigned int sectors)
1469 {
1470 	struct ata_taskfile tf;
1471 	unsigned int err_mask;
1472 
1473 	DPRINTK("read log page - page %d\n", page);
1474 
1475 	ata_tf_init(dev, &tf);
1476 	tf.command = ATA_CMD_READ_LOG_EXT;
1477 	tf.lbal = page;
1478 	tf.nsect = sectors;
1479 	tf.hob_nsect = sectors >> 8;
1480 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_LBA48 | ATA_TFLAG_DEVICE;
1481 	tf.protocol = ATA_PROT_PIO;
1482 
1483 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
1484 				     buf, sectors * ATA_SECT_SIZE, 0);
1485 
1486 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
1487 	return err_mask;
1488 }
1489 
1490 /**
1491  *	ata_eh_read_log_10h - Read log page 10h for NCQ error details
1492  *	@dev: Device to read log page 10h from
1493  *	@tag: Resulting tag of the failed command
1494  *	@tf: Resulting taskfile registers of the failed command
1495  *
1496  *	Read log page 10h to obtain NCQ error details and clear error
1497  *	condition.
1498  *
1499  *	LOCKING:
1500  *	Kernel thread context (may sleep).
1501  *
1502  *	RETURNS:
1503  *	0 on success, -errno otherwise.
1504  */
1505 static int ata_eh_read_log_10h(struct ata_device *dev,
1506 			       int *tag, struct ata_taskfile *tf)
1507 {
1508 	u8 *buf = dev->link->ap->sector_buf;
1509 	unsigned int err_mask;
1510 	u8 csum;
1511 	int i;
1512 
1513 	err_mask = ata_read_log_page(dev, ATA_LOG_SATA_NCQ, buf, 1);
1514 	if (err_mask)
1515 		return -EIO;
1516 
1517 	csum = 0;
1518 	for (i = 0; i < ATA_SECT_SIZE; i++)
1519 		csum += buf[i];
1520 	if (csum)
1521 		ata_dev_warn(dev, "invalid checksum 0x%x on log page 10h\n",
1522 			     csum);
1523 
1524 	if (buf[0] & 0x80)
1525 		return -ENOENT;
1526 
1527 	*tag = buf[0] & 0x1f;
1528 
1529 	tf->command = buf[2];
1530 	tf->feature = buf[3];
1531 	tf->lbal = buf[4];
1532 	tf->lbam = buf[5];
1533 	tf->lbah = buf[6];
1534 	tf->device = buf[7];
1535 	tf->hob_lbal = buf[8];
1536 	tf->hob_lbam = buf[9];
1537 	tf->hob_lbah = buf[10];
1538 	tf->nsect = buf[12];
1539 	tf->hob_nsect = buf[13];
1540 
1541 	return 0;
1542 }
1543 
1544 /**
1545  *	atapi_eh_tur - perform ATAPI TEST_UNIT_READY
1546  *	@dev: target ATAPI device
1547  *	@r_sense_key: out parameter for sense_key
1548  *
1549  *	Perform ATAPI TEST_UNIT_READY.
1550  *
1551  *	LOCKING:
1552  *	EH context (may sleep).
1553  *
1554  *	RETURNS:
1555  *	0 on success, AC_ERR_* mask on failure.
1556  */
1557 static unsigned int atapi_eh_tur(struct ata_device *dev, u8 *r_sense_key)
1558 {
1559 	u8 cdb[ATAPI_CDB_LEN] = { TEST_UNIT_READY, 0, 0, 0, 0, 0 };
1560 	struct ata_taskfile tf;
1561 	unsigned int err_mask;
1562 
1563 	ata_tf_init(dev, &tf);
1564 
1565 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1566 	tf.command = ATA_CMD_PACKET;
1567 	tf.protocol = ATAPI_PROT_NODATA;
1568 
1569 	err_mask = ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
1570 	if (err_mask == AC_ERR_DEV)
1571 		*r_sense_key = tf.feature >> 4;
1572 	return err_mask;
1573 }
1574 
1575 /**
1576  *	atapi_eh_request_sense - perform ATAPI REQUEST_SENSE
1577  *	@dev: device to perform REQUEST_SENSE to
1578  *	@sense_buf: result sense data buffer (SCSI_SENSE_BUFFERSIZE bytes long)
1579  *	@dfl_sense_key: default sense key to use
1580  *
1581  *	Perform ATAPI REQUEST_SENSE after the device reported CHECK
1582  *	SENSE.  This function is EH helper.
1583  *
1584  *	LOCKING:
1585  *	Kernel thread context (may sleep).
1586  *
1587  *	RETURNS:
1588  *	0 on success, AC_ERR_* mask on failure
1589  */
1590 static unsigned int atapi_eh_request_sense(struct ata_device *dev,
1591 					   u8 *sense_buf, u8 dfl_sense_key)
1592 {
1593 	u8 cdb[ATAPI_CDB_LEN] =
1594 		{ REQUEST_SENSE, 0, 0, 0, SCSI_SENSE_BUFFERSIZE, 0 };
1595 	struct ata_port *ap = dev->link->ap;
1596 	struct ata_taskfile tf;
1597 
1598 	DPRINTK("ATAPI request sense\n");
1599 
1600 	/* FIXME: is this needed? */
1601 	memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);
1602 
1603 	/* initialize sense_buf with the error register,
1604 	 * for the case where they are -not- overwritten
1605 	 */
1606 	sense_buf[0] = 0x70;
1607 	sense_buf[2] = dfl_sense_key;
1608 
1609 	/* some devices time out if garbage left in tf */
1610 	ata_tf_init(dev, &tf);
1611 
1612 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1613 	tf.command = ATA_CMD_PACKET;
1614 
1615 	/* is it pointless to prefer PIO for "safety reasons"? */
1616 	if (ap->flags & ATA_FLAG_PIO_DMA) {
1617 		tf.protocol = ATAPI_PROT_DMA;
1618 		tf.feature |= ATAPI_PKT_DMA;
1619 	} else {
1620 		tf.protocol = ATAPI_PROT_PIO;
1621 		tf.lbam = SCSI_SENSE_BUFFERSIZE;
1622 		tf.lbah = 0;
1623 	}
1624 
1625 	return ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,
1626 				 sense_buf, SCSI_SENSE_BUFFERSIZE, 0);
1627 }
1628 
1629 /**
1630  *	ata_eh_analyze_serror - analyze SError for a failed port
1631  *	@link: ATA link to analyze SError for
1632  *
1633  *	Analyze SError if available and further determine cause of
1634  *	failure.
1635  *
1636  *	LOCKING:
1637  *	None.
1638  */
1639 static void ata_eh_analyze_serror(struct ata_link *link)
1640 {
1641 	struct ata_eh_context *ehc = &link->eh_context;
1642 	u32 serror = ehc->i.serror;
1643 	unsigned int err_mask = 0, action = 0;
1644 	u32 hotplug_mask;
1645 
1646 	if (serror & (SERR_PERSISTENT | SERR_DATA)) {
1647 		err_mask |= AC_ERR_ATA_BUS;
1648 		action |= ATA_EH_RESET;
1649 	}
1650 	if (serror & SERR_PROTOCOL) {
1651 		err_mask |= AC_ERR_HSM;
1652 		action |= ATA_EH_RESET;
1653 	}
1654 	if (serror & SERR_INTERNAL) {
1655 		err_mask |= AC_ERR_SYSTEM;
1656 		action |= ATA_EH_RESET;
1657 	}
1658 
1659 	/* Determine whether a hotplug event has occurred.  Both
1660 	 * SError.N/X are considered hotplug events for enabled or
1661 	 * host links.  For disabled PMP links, only N bit is
1662 	 * considered as X bit is left at 1 for link plugging.
1663 	 */
1664 	if (link->lpm_policy > ATA_LPM_MAX_POWER)
1665 		hotplug_mask = 0;	/* hotplug doesn't work w/ LPM */
1666 	else if (!(link->flags & ATA_LFLAG_DISABLED) || ata_is_host_link(link))
1667 		hotplug_mask = SERR_PHYRDY_CHG | SERR_DEV_XCHG;
1668 	else
1669 		hotplug_mask = SERR_PHYRDY_CHG;
1670 
1671 	if (serror & hotplug_mask)
1672 		ata_ehi_hotplugged(&ehc->i);
1673 
1674 	ehc->i.err_mask |= err_mask;
1675 	ehc->i.action |= action;
1676 }
1677 
1678 /**
1679  *	ata_eh_analyze_ncq_error - analyze NCQ error
1680  *	@link: ATA link to analyze NCQ error for
1681  *
1682  *	Read log page 10h, determine the offending qc and acquire
1683  *	error status TF.  For NCQ device errors, all LLDDs have to do
1684  *	is setting AC_ERR_DEV in ehi->err_mask.  This function takes
1685  *	care of the rest.
1686  *
1687  *	LOCKING:
1688  *	Kernel thread context (may sleep).
1689  */
1690 void ata_eh_analyze_ncq_error(struct ata_link *link)
1691 {
1692 	struct ata_port *ap = link->ap;
1693 	struct ata_eh_context *ehc = &link->eh_context;
1694 	struct ata_device *dev = link->device;
1695 	struct ata_queued_cmd *qc;
1696 	struct ata_taskfile tf;
1697 	int tag, rc;
1698 
1699 	/* if frozen, we can't do much */
1700 	if (ap->pflags & ATA_PFLAG_FROZEN)
1701 		return;
1702 
1703 	/* is it NCQ device error? */
1704 	if (!link->sactive || !(ehc->i.err_mask & AC_ERR_DEV))
1705 		return;
1706 
1707 	/* has LLDD analyzed already? */
1708 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
1709 		qc = __ata_qc_from_tag(ap, tag);
1710 
1711 		if (!(qc->flags & ATA_QCFLAG_FAILED))
1712 			continue;
1713 
1714 		if (qc->err_mask)
1715 			return;
1716 	}
1717 
1718 	/* okay, this error is ours */
1719 	memset(&tf, 0, sizeof(tf));
1720 	rc = ata_eh_read_log_10h(dev, &tag, &tf);
1721 	if (rc) {
1722 		ata_link_err(link, "failed to read log page 10h (errno=%d)\n",
1723 			     rc);
1724 		return;
1725 	}
1726 
1727 	if (!(link->sactive & (1 << tag))) {
1728 		ata_link_err(link, "log page 10h reported inactive tag %d\n",
1729 			     tag);
1730 		return;
1731 	}
1732 
1733 	/* we've got the perpetrator, condemn it */
1734 	qc = __ata_qc_from_tag(ap, tag);
1735 	memcpy(&qc->result_tf, &tf, sizeof(tf));
1736 	qc->result_tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
1737 	qc->err_mask |= AC_ERR_DEV | AC_ERR_NCQ;
1738 	ehc->i.err_mask &= ~AC_ERR_DEV;
1739 }
1740 
1741 /**
1742  *	ata_eh_analyze_tf - analyze taskfile of a failed qc
1743  *	@qc: qc to analyze
1744  *	@tf: Taskfile registers to analyze
1745  *
1746  *	Analyze taskfile of @qc and further determine cause of
1747  *	failure.  This function also requests ATAPI sense data if
1748  *	available.
1749  *
1750  *	LOCKING:
1751  *	Kernel thread context (may sleep).
1752  *
1753  *	RETURNS:
1754  *	Determined recovery action
1755  */
1756 static unsigned int ata_eh_analyze_tf(struct ata_queued_cmd *qc,
1757 				      const struct ata_taskfile *tf)
1758 {
1759 	unsigned int tmp, action = 0;
1760 	u8 stat = tf->command, err = tf->feature;
1761 
1762 	if ((stat & (ATA_BUSY | ATA_DRQ | ATA_DRDY)) != ATA_DRDY) {
1763 		qc->err_mask |= AC_ERR_HSM;
1764 		return ATA_EH_RESET;
1765 	}
1766 
1767 	if (stat & (ATA_ERR | ATA_DF))
1768 		qc->err_mask |= AC_ERR_DEV;
1769 	else
1770 		return 0;
1771 
1772 	switch (qc->dev->class) {
1773 	case ATA_DEV_ATA:
1774 		if (err & ATA_ICRC)
1775 			qc->err_mask |= AC_ERR_ATA_BUS;
1776 		if (err & ATA_UNC)
1777 			qc->err_mask |= AC_ERR_MEDIA;
1778 		if (err & ATA_IDNF)
1779 			qc->err_mask |= AC_ERR_INVALID;
1780 		break;
1781 
1782 	case ATA_DEV_ATAPI:
1783 		if (!(qc->ap->pflags & ATA_PFLAG_FROZEN)) {
1784 			tmp = atapi_eh_request_sense(qc->dev,
1785 						qc->scsicmd->sense_buffer,
1786 						qc->result_tf.feature >> 4);
1787 			if (!tmp) {
1788 				/* ATA_QCFLAG_SENSE_VALID is used to
1789 				 * tell atapi_qc_complete() that sense
1790 				 * data is already valid.
1791 				 *
1792 				 * TODO: interpret sense data and set
1793 				 * appropriate err_mask.
1794 				 */
1795 				qc->flags |= ATA_QCFLAG_SENSE_VALID;
1796 			} else
1797 				qc->err_mask |= tmp;
1798 		}
1799 	}
1800 
1801 	if (qc->err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT | AC_ERR_ATA_BUS))
1802 		action |= ATA_EH_RESET;
1803 
1804 	return action;
1805 }
1806 
1807 static int ata_eh_categorize_error(unsigned int eflags, unsigned int err_mask,
1808 				   int *xfer_ok)
1809 {
1810 	int base = 0;
1811 
1812 	if (!(eflags & ATA_EFLAG_DUBIOUS_XFER))
1813 		*xfer_ok = 1;
1814 
1815 	if (!*xfer_ok)
1816 		base = ATA_ECAT_DUBIOUS_NONE;
1817 
1818 	if (err_mask & AC_ERR_ATA_BUS)
1819 		return base + ATA_ECAT_ATA_BUS;
1820 
1821 	if (err_mask & AC_ERR_TIMEOUT)
1822 		return base + ATA_ECAT_TOUT_HSM;
1823 
1824 	if (eflags & ATA_EFLAG_IS_IO) {
1825 		if (err_mask & AC_ERR_HSM)
1826 			return base + ATA_ECAT_TOUT_HSM;
1827 		if ((err_mask &
1828 		     (AC_ERR_DEV|AC_ERR_MEDIA|AC_ERR_INVALID)) == AC_ERR_DEV)
1829 			return base + ATA_ECAT_UNK_DEV;
1830 	}
1831 
1832 	return 0;
1833 }
1834 
1835 struct speed_down_verdict_arg {
1836 	u64 since;
1837 	int xfer_ok;
1838 	int nr_errors[ATA_ECAT_NR];
1839 };
1840 
1841 static int speed_down_verdict_cb(struct ata_ering_entry *ent, void *void_arg)
1842 {
1843 	struct speed_down_verdict_arg *arg = void_arg;
1844 	int cat;
1845 
1846 	if ((ent->eflags & ATA_EFLAG_OLD_ER) || (ent->timestamp < arg->since))
1847 		return -1;
1848 
1849 	cat = ata_eh_categorize_error(ent->eflags, ent->err_mask,
1850 				      &arg->xfer_ok);
1851 	arg->nr_errors[cat]++;
1852 
1853 	return 0;
1854 }
1855 
1856 /**
1857  *	ata_eh_speed_down_verdict - Determine speed down verdict
1858  *	@dev: Device of interest
1859  *
1860  *	This function examines error ring of @dev and determines
1861  *	whether NCQ needs to be turned off, transfer speed should be
1862  *	stepped down, or falling back to PIO is necessary.
1863  *
1864  *	ECAT_ATA_BUS	: ATA_BUS error for any command
1865  *
1866  *	ECAT_TOUT_HSM	: TIMEOUT for any command or HSM violation for
1867  *			  IO commands
1868  *
1869  *	ECAT_UNK_DEV	: Unknown DEV error for IO commands
1870  *
1871  *	ECAT_DUBIOUS_*	: Identical to above three but occurred while
1872  *			  data transfer hasn't been verified.
1873  *
1874  *	Verdicts are
1875  *
1876  *	NCQ_OFF		: Turn off NCQ.
1877  *
1878  *	SPEED_DOWN	: Speed down transfer speed but don't fall back
1879  *			  to PIO.
1880  *
1881  *	FALLBACK_TO_PIO	: Fall back to PIO.
1882  *
1883  *	Even if multiple verdicts are returned, only one action is
1884  *	taken per error.  An action triggered by non-DUBIOUS errors
1885  *	clears ering, while one triggered by DUBIOUS_* errors doesn't.
1886  *	This is to expedite speed down decisions right after device is
1887  *	initially configured.
1888  *
1889  *	The followings are speed down rules.  #1 and #2 deal with
1890  *	DUBIOUS errors.
1891  *
1892  *	1. If more than one DUBIOUS_ATA_BUS or DUBIOUS_TOUT_HSM errors
1893  *	   occurred during last 5 mins, SPEED_DOWN and FALLBACK_TO_PIO.
1894  *
1895  *	2. If more than one DUBIOUS_TOUT_HSM or DUBIOUS_UNK_DEV errors
1896  *	   occurred during last 5 mins, NCQ_OFF.
1897  *
1898  *	3. If more than 8 ATA_BUS, TOUT_HSM or UNK_DEV errors
1899  *	   occurred during last 5 mins, FALLBACK_TO_PIO
1900  *
1901  *	4. If more than 3 TOUT_HSM or UNK_DEV errors occurred
1902  *	   during last 10 mins, NCQ_OFF.
1903  *
1904  *	5. If more than 3 ATA_BUS or TOUT_HSM errors, or more than 6
1905  *	   UNK_DEV errors occurred during last 10 mins, SPEED_DOWN.
1906  *
1907  *	LOCKING:
1908  *	Inherited from caller.
1909  *
1910  *	RETURNS:
1911  *	OR of ATA_EH_SPDN_* flags.
1912  */
1913 static unsigned int ata_eh_speed_down_verdict(struct ata_device *dev)
1914 {
1915 	const u64 j5mins = 5LLU * 60 * HZ, j10mins = 10LLU * 60 * HZ;
1916 	u64 j64 = get_jiffies_64();
1917 	struct speed_down_verdict_arg arg;
1918 	unsigned int verdict = 0;
1919 
1920 	/* scan past 5 mins of error history */
1921 	memset(&arg, 0, sizeof(arg));
1922 	arg.since = j64 - min(j64, j5mins);
1923 	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);
1924 
1925 	if (arg.nr_errors[ATA_ECAT_DUBIOUS_ATA_BUS] +
1926 	    arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] > 1)
1927 		verdict |= ATA_EH_SPDN_SPEED_DOWN |
1928 			ATA_EH_SPDN_FALLBACK_TO_PIO | ATA_EH_SPDN_KEEP_ERRORS;
1929 
1930 	if (arg.nr_errors[ATA_ECAT_DUBIOUS_TOUT_HSM] +
1931 	    arg.nr_errors[ATA_ECAT_DUBIOUS_UNK_DEV] > 1)
1932 		verdict |= ATA_EH_SPDN_NCQ_OFF | ATA_EH_SPDN_KEEP_ERRORS;
1933 
1934 	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
1935 	    arg.nr_errors[ATA_ECAT_TOUT_HSM] +
1936 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
1937 		verdict |= ATA_EH_SPDN_FALLBACK_TO_PIO;
1938 
1939 	/* scan past 10 mins of error history */
1940 	memset(&arg, 0, sizeof(arg));
1941 	arg.since = j64 - min(j64, j10mins);
1942 	ata_ering_map(&dev->ering, speed_down_verdict_cb, &arg);
1943 
1944 	if (arg.nr_errors[ATA_ECAT_TOUT_HSM] +
1945 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 3)
1946 		verdict |= ATA_EH_SPDN_NCQ_OFF;
1947 
1948 	if (arg.nr_errors[ATA_ECAT_ATA_BUS] +
1949 	    arg.nr_errors[ATA_ECAT_TOUT_HSM] > 3 ||
1950 	    arg.nr_errors[ATA_ECAT_UNK_DEV] > 6)
1951 		verdict |= ATA_EH_SPDN_SPEED_DOWN;
1952 
1953 	return verdict;
1954 }
1955 
1956 /**
1957  *	ata_eh_speed_down - record error and speed down if necessary
1958  *	@dev: Failed device
1959  *	@eflags: mask of ATA_EFLAG_* flags
1960  *	@err_mask: err_mask of the error
1961  *
1962  *	Record error and examine error history to determine whether
1963  *	adjusting transmission speed is necessary.  It also sets
1964  *	transmission limits appropriately if such adjustment is
1965  *	necessary.
1966  *
1967  *	LOCKING:
1968  *	Kernel thread context (may sleep).
1969  *
1970  *	RETURNS:
1971  *	Determined recovery action.
1972  */
1973 static unsigned int ata_eh_speed_down(struct ata_device *dev,
1974 				unsigned int eflags, unsigned int err_mask)
1975 {
1976 	struct ata_link *link = ata_dev_phys_link(dev);
1977 	int xfer_ok = 0;
1978 	unsigned int verdict;
1979 	unsigned int action = 0;
1980 
1981 	/* don't bother if Cat-0 error */
1982 	if (ata_eh_categorize_error(eflags, err_mask, &xfer_ok) == 0)
1983 		return 0;
1984 
1985 	/* record error and determine whether speed down is necessary */
1986 	ata_ering_record(&dev->ering, eflags, err_mask);
1987 	verdict = ata_eh_speed_down_verdict(dev);
1988 
1989 	/* turn off NCQ? */
1990 	if ((verdict & ATA_EH_SPDN_NCQ_OFF) &&
1991 	    (dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ |
1992 			   ATA_DFLAG_NCQ_OFF)) == ATA_DFLAG_NCQ) {
1993 		dev->flags |= ATA_DFLAG_NCQ_OFF;
1994 		ata_dev_warn(dev, "NCQ disabled due to excessive errors\n");
1995 		goto done;
1996 	}
1997 
1998 	/* speed down? */
1999 	if (verdict & ATA_EH_SPDN_SPEED_DOWN) {
2000 		/* speed down SATA link speed if possible */
2001 		if (sata_down_spd_limit(link, 0) == 0) {
2002 			action |= ATA_EH_RESET;
2003 			goto done;
2004 		}
2005 
2006 		/* lower transfer mode */
2007 		if (dev->spdn_cnt < 2) {
2008 			static const int dma_dnxfer_sel[] =
2009 				{ ATA_DNXFER_DMA, ATA_DNXFER_40C };
2010 			static const int pio_dnxfer_sel[] =
2011 				{ ATA_DNXFER_PIO, ATA_DNXFER_FORCE_PIO0 };
2012 			int sel;
2013 
2014 			if (dev->xfer_shift != ATA_SHIFT_PIO)
2015 				sel = dma_dnxfer_sel[dev->spdn_cnt];
2016 			else
2017 				sel = pio_dnxfer_sel[dev->spdn_cnt];
2018 
2019 			dev->spdn_cnt++;
2020 
2021 			if (ata_down_xfermask_limit(dev, sel) == 0) {
2022 				action |= ATA_EH_RESET;
2023 				goto done;
2024 			}
2025 		}
2026 	}
2027 
2028 	/* Fall back to PIO?  Slowing down to PIO is meaningless for
2029 	 * SATA ATA devices.  Consider it only for PATA and SATAPI.
2030 	 */
2031 	if ((verdict & ATA_EH_SPDN_FALLBACK_TO_PIO) && (dev->spdn_cnt >= 2) &&
2032 	    (link->ap->cbl != ATA_CBL_SATA || dev->class == ATA_DEV_ATAPI) &&
2033 	    (dev->xfer_shift != ATA_SHIFT_PIO)) {
2034 		if (ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO) == 0) {
2035 			dev->spdn_cnt = 0;
2036 			action |= ATA_EH_RESET;
2037 			goto done;
2038 		}
2039 	}
2040 
2041 	return 0;
2042  done:
2043 	/* device has been slowed down, blow error history */
2044 	if (!(verdict & ATA_EH_SPDN_KEEP_ERRORS))
2045 		ata_ering_clear(&dev->ering);
2046 	return action;
2047 }
2048 
2049 /**
2050  *	ata_eh_link_autopsy - analyze error and determine recovery action
2051  *	@link: host link to perform autopsy on
2052  *
2053  *	Analyze why @link failed and determine which recovery actions
2054  *	are needed.  This function also sets more detailed AC_ERR_*
2055  *	values and fills sense data for ATAPI CHECK SENSE.
2056  *
2057  *	LOCKING:
2058  *	Kernel thread context (may sleep).
2059  */
2060 static void ata_eh_link_autopsy(struct ata_link *link)
2061 {
2062 	struct ata_port *ap = link->ap;
2063 	struct ata_eh_context *ehc = &link->eh_context;
2064 	struct ata_device *dev;
2065 	unsigned int all_err_mask = 0, eflags = 0;
2066 	int tag;
2067 	u32 serror;
2068 	int rc;
2069 
2070 	DPRINTK("ENTER\n");
2071 
2072 	if (ehc->i.flags & ATA_EHI_NO_AUTOPSY)
2073 		return;
2074 
2075 	/* obtain and analyze SError */
2076 	rc = sata_scr_read(link, SCR_ERROR, &serror);
2077 	if (rc == 0) {
2078 		ehc->i.serror |= serror;
2079 		ata_eh_analyze_serror(link);
2080 	} else if (rc != -EOPNOTSUPP) {
2081 		/* SError read failed, force reset and probing */
2082 		ehc->i.probe_mask |= ATA_ALL_DEVICES;
2083 		ehc->i.action |= ATA_EH_RESET;
2084 		ehc->i.err_mask |= AC_ERR_OTHER;
2085 	}
2086 
2087 	/* analyze NCQ failure */
2088 	ata_eh_analyze_ncq_error(link);
2089 
2090 	/* any real error trumps AC_ERR_OTHER */
2091 	if (ehc->i.err_mask & ~AC_ERR_OTHER)
2092 		ehc->i.err_mask &= ~AC_ERR_OTHER;
2093 
2094 	all_err_mask |= ehc->i.err_mask;
2095 
2096 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
2097 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
2098 
2099 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
2100 		    ata_dev_phys_link(qc->dev) != link)
2101 			continue;
2102 
2103 		/* inherit upper level err_mask */
2104 		qc->err_mask |= ehc->i.err_mask;
2105 
2106 		/* analyze TF */
2107 		ehc->i.action |= ata_eh_analyze_tf(qc, &qc->result_tf);
2108 
2109 		/* DEV errors are probably spurious in case of ATA_BUS error */
2110 		if (qc->err_mask & AC_ERR_ATA_BUS)
2111 			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_MEDIA |
2112 					  AC_ERR_INVALID);
2113 
2114 		/* any real error trumps unknown error */
2115 		if (qc->err_mask & ~AC_ERR_OTHER)
2116 			qc->err_mask &= ~AC_ERR_OTHER;
2117 
2118 		/* SENSE_VALID trumps dev/unknown error and revalidation */
2119 		if (qc->flags & ATA_QCFLAG_SENSE_VALID)
2120 			qc->err_mask &= ~(AC_ERR_DEV | AC_ERR_OTHER);
2121 
2122 		/* determine whether the command is worth retrying */
2123 		if (qc->flags & ATA_QCFLAG_IO ||
2124 		    (!(qc->err_mask & AC_ERR_INVALID) &&
2125 		     qc->err_mask != AC_ERR_DEV))
2126 			qc->flags |= ATA_QCFLAG_RETRY;
2127 
2128 		/* accumulate error info */
2129 		ehc->i.dev = qc->dev;
2130 		all_err_mask |= qc->err_mask;
2131 		if (qc->flags & ATA_QCFLAG_IO)
2132 			eflags |= ATA_EFLAG_IS_IO;
2133 	}
2134 
2135 	/* enforce default EH actions */
2136 	if (ap->pflags & ATA_PFLAG_FROZEN ||
2137 	    all_err_mask & (AC_ERR_HSM | AC_ERR_TIMEOUT))
2138 		ehc->i.action |= ATA_EH_RESET;
2139 	else if (((eflags & ATA_EFLAG_IS_IO) && all_err_mask) ||
2140 		 (!(eflags & ATA_EFLAG_IS_IO) && (all_err_mask & ~AC_ERR_DEV)))
2141 		ehc->i.action |= ATA_EH_REVALIDATE;
2142 
2143 	/* If we have offending qcs and the associated failed device,
2144 	 * perform per-dev EH action only on the offending device.
2145 	 */
2146 	if (ehc->i.dev) {
2147 		ehc->i.dev_action[ehc->i.dev->devno] |=
2148 			ehc->i.action & ATA_EH_PERDEV_MASK;
2149 		ehc->i.action &= ~ATA_EH_PERDEV_MASK;
2150 	}
2151 
2152 	/* propagate timeout to host link */
2153 	if ((all_err_mask & AC_ERR_TIMEOUT) && !ata_is_host_link(link))
2154 		ap->link.eh_context.i.err_mask |= AC_ERR_TIMEOUT;
2155 
2156 	/* record error and consider speeding down */
2157 	dev = ehc->i.dev;
2158 	if (!dev && ((ata_link_max_devices(link) == 1 &&
2159 		      ata_dev_enabled(link->device))))
2160 	    dev = link->device;
2161 
2162 	if (dev) {
2163 		if (dev->flags & ATA_DFLAG_DUBIOUS_XFER)
2164 			eflags |= ATA_EFLAG_DUBIOUS_XFER;
2165 		ehc->i.action |= ata_eh_speed_down(dev, eflags, all_err_mask);
2166 	}
2167 
2168 	DPRINTK("EXIT\n");
2169 }
2170 
2171 /**
2172  *	ata_eh_autopsy - analyze error and determine recovery action
2173  *	@ap: host port to perform autopsy on
2174  *
2175  *	Analyze all links of @ap and determine why they failed and
2176  *	which recovery actions are needed.
2177  *
2178  *	LOCKING:
2179  *	Kernel thread context (may sleep).
2180  */
2181 void ata_eh_autopsy(struct ata_port *ap)
2182 {
2183 	struct ata_link *link;
2184 
2185 	ata_for_each_link(link, ap, EDGE)
2186 		ata_eh_link_autopsy(link);
2187 
2188 	/* Handle the frigging slave link.  Autopsy is done similarly
2189 	 * but actions and flags are transferred over to the master
2190 	 * link and handled from there.
2191 	 */
2192 	if (ap->slave_link) {
2193 		struct ata_eh_context *mehc = &ap->link.eh_context;
2194 		struct ata_eh_context *sehc = &ap->slave_link->eh_context;
2195 
2196 		/* transfer control flags from master to slave */
2197 		sehc->i.flags |= mehc->i.flags & ATA_EHI_TO_SLAVE_MASK;
2198 
2199 		/* perform autopsy on the slave link */
2200 		ata_eh_link_autopsy(ap->slave_link);
2201 
2202 		/* transfer actions from slave to master and clear slave */
2203 		ata_eh_about_to_do(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
2204 		mehc->i.action		|= sehc->i.action;
2205 		mehc->i.dev_action[1]	|= sehc->i.dev_action[1];
2206 		mehc->i.flags		|= sehc->i.flags;
2207 		ata_eh_done(ap->slave_link, NULL, ATA_EH_ALL_ACTIONS);
2208 	}
2209 
2210 	/* Autopsy of fanout ports can affect host link autopsy.
2211 	 * Perform host link autopsy last.
2212 	 */
2213 	if (sata_pmp_attached(ap))
2214 		ata_eh_link_autopsy(&ap->link);
2215 }
2216 
2217 /**
2218  *	ata_get_cmd_descript - get description for ATA command
2219  *	@command: ATA command code to get description for
2220  *
2221  *	Return a textual description of the given command, or NULL if the
2222  *	command is not known.
2223  *
2224  *	LOCKING:
2225  *	None
2226  */
2227 const char *ata_get_cmd_descript(u8 command)
2228 {
2229 #ifdef CONFIG_ATA_VERBOSE_ERROR
2230 	static const struct
2231 	{
2232 		u8 command;
2233 		const char *text;
2234 	} cmd_descr[] = {
2235 		{ ATA_CMD_DEV_RESET,		"DEVICE RESET" },
2236 		{ ATA_CMD_CHK_POWER, 		"CHECK POWER MODE" },
2237 		{ ATA_CMD_STANDBY, 		"STANDBY" },
2238 		{ ATA_CMD_IDLE, 		"IDLE" },
2239 		{ ATA_CMD_EDD, 			"EXECUTE DEVICE DIAGNOSTIC" },
2240 		{ ATA_CMD_DOWNLOAD_MICRO,   	"DOWNLOAD MICROCODE" },
2241 		{ ATA_CMD_NOP,			"NOP" },
2242 		{ ATA_CMD_FLUSH, 		"FLUSH CACHE" },
2243 		{ ATA_CMD_FLUSH_EXT, 		"FLUSH CACHE EXT" },
2244 		{ ATA_CMD_ID_ATA,  		"IDENTIFY DEVICE" },
2245 		{ ATA_CMD_ID_ATAPI, 		"IDENTIFY PACKET DEVICE" },
2246 		{ ATA_CMD_SERVICE, 		"SERVICE" },
2247 		{ ATA_CMD_READ, 		"READ DMA" },
2248 		{ ATA_CMD_READ_EXT, 		"READ DMA EXT" },
2249 		{ ATA_CMD_READ_QUEUED, 		"READ DMA QUEUED" },
2250 		{ ATA_CMD_READ_STREAM_EXT, 	"READ STREAM EXT" },
2251 		{ ATA_CMD_READ_STREAM_DMA_EXT,  "READ STREAM DMA EXT" },
2252 		{ ATA_CMD_WRITE, 		"WRITE DMA" },
2253 		{ ATA_CMD_WRITE_EXT, 		"WRITE DMA EXT" },
2254 		{ ATA_CMD_WRITE_QUEUED, 	"WRITE DMA QUEUED EXT" },
2255 		{ ATA_CMD_WRITE_STREAM_EXT, 	"WRITE STREAM EXT" },
2256 		{ ATA_CMD_WRITE_STREAM_DMA_EXT, "WRITE STREAM DMA EXT" },
2257 		{ ATA_CMD_WRITE_FUA_EXT,	"WRITE DMA FUA EXT" },
2258 		{ ATA_CMD_WRITE_QUEUED_FUA_EXT, "WRITE DMA QUEUED FUA EXT" },
2259 		{ ATA_CMD_FPDMA_READ,		"READ FPDMA QUEUED" },
2260 		{ ATA_CMD_FPDMA_WRITE,		"WRITE FPDMA QUEUED" },
2261 		{ ATA_CMD_PIO_READ,		"READ SECTOR(S)" },
2262 		{ ATA_CMD_PIO_READ_EXT,		"READ SECTOR(S) EXT" },
2263 		{ ATA_CMD_PIO_WRITE,		"WRITE SECTOR(S)" },
2264 		{ ATA_CMD_PIO_WRITE_EXT,	"WRITE SECTOR(S) EXT" },
2265 		{ ATA_CMD_READ_MULTI,		"READ MULTIPLE" },
2266 		{ ATA_CMD_READ_MULTI_EXT,	"READ MULTIPLE EXT" },
2267 		{ ATA_CMD_WRITE_MULTI,		"WRITE MULTIPLE" },
2268 		{ ATA_CMD_WRITE_MULTI_EXT,	"WRITE MULTIPLE EXT" },
2269 		{ ATA_CMD_WRITE_MULTI_FUA_EXT, 	"WRITE MULTIPLE FUA EXT" },
2270 		{ ATA_CMD_SET_FEATURES,		"SET FEATURES" },
2271 		{ ATA_CMD_SET_MULTI,		"SET MULTIPLE MODE" },
2272 		{ ATA_CMD_VERIFY,		"READ VERIFY SECTOR(S)" },
2273 		{ ATA_CMD_VERIFY_EXT,		"READ VERIFY SECTOR(S) EXT" },
2274 		{ ATA_CMD_WRITE_UNCORR_EXT,	"WRITE UNCORRECTABLE EXT" },
2275 		{ ATA_CMD_STANDBYNOW1,		"STANDBY IMMEDIATE" },
2276 		{ ATA_CMD_IDLEIMMEDIATE,	"IDLE IMMEDIATE" },
2277 		{ ATA_CMD_SLEEP,		"SLEEP" },
2278 		{ ATA_CMD_INIT_DEV_PARAMS,	"INITIALIZE DEVICE PARAMETERS" },
2279 		{ ATA_CMD_READ_NATIVE_MAX,	"READ NATIVE MAX ADDRESS" },
2280 		{ ATA_CMD_READ_NATIVE_MAX_EXT,	"READ NATIVE MAX ADDRESS EXT" },
2281 		{ ATA_CMD_SET_MAX,		"SET MAX ADDRESS" },
2282 		{ ATA_CMD_SET_MAX_EXT,		"SET MAX ADDRESS EXT" },
2283 		{ ATA_CMD_READ_LOG_EXT,		"READ LOG EXT" },
2284 		{ ATA_CMD_WRITE_LOG_EXT,	"WRITE LOG EXT" },
2285 		{ ATA_CMD_READ_LOG_DMA_EXT,	"READ LOG DMA EXT" },
2286 		{ ATA_CMD_WRITE_LOG_DMA_EXT, 	"WRITE LOG DMA EXT" },
2287 		{ ATA_CMD_TRUSTED_RCV,		"TRUSTED RECEIVE" },
2288 		{ ATA_CMD_TRUSTED_RCV_DMA, 	"TRUSTED RECEIVE DMA" },
2289 		{ ATA_CMD_TRUSTED_SND,		"TRUSTED SEND" },
2290 		{ ATA_CMD_TRUSTED_SND_DMA, 	"TRUSTED SEND DMA" },
2291 		{ ATA_CMD_PMP_READ,		"READ BUFFER" },
2292 		{ ATA_CMD_PMP_WRITE,		"WRITE BUFFER" },
2293 		{ ATA_CMD_CONF_OVERLAY,		"DEVICE CONFIGURATION OVERLAY" },
2294 		{ ATA_CMD_SEC_SET_PASS,		"SECURITY SET PASSWORD" },
2295 		{ ATA_CMD_SEC_UNLOCK,		"SECURITY UNLOCK" },
2296 		{ ATA_CMD_SEC_ERASE_PREP,	"SECURITY ERASE PREPARE" },
2297 		{ ATA_CMD_SEC_ERASE_UNIT,	"SECURITY ERASE UNIT" },
2298 		{ ATA_CMD_SEC_FREEZE_LOCK,	"SECURITY FREEZE LOCK" },
2299 		{ ATA_CMD_SEC_DISABLE_PASS,	"SECURITY DISABLE PASSWORD" },
2300 		{ ATA_CMD_CONFIG_STREAM,	"CONFIGURE STREAM" },
2301 		{ ATA_CMD_SMART,		"SMART" },
2302 		{ ATA_CMD_MEDIA_LOCK,		"DOOR LOCK" },
2303 		{ ATA_CMD_MEDIA_UNLOCK,		"DOOR UNLOCK" },
2304 		{ ATA_CMD_DSM,			"DATA SET MANAGEMENT" },
2305 		{ ATA_CMD_CHK_MED_CRD_TYP, 	"CHECK MEDIA CARD TYPE" },
2306 		{ ATA_CMD_CFA_REQ_EXT_ERR, 	"CFA REQUEST EXTENDED ERROR" },
2307 		{ ATA_CMD_CFA_WRITE_NE,		"CFA WRITE SECTORS WITHOUT ERASE" },
2308 		{ ATA_CMD_CFA_TRANS_SECT,	"CFA TRANSLATE SECTOR" },
2309 		{ ATA_CMD_CFA_ERASE,		"CFA ERASE SECTORS" },
2310 		{ ATA_CMD_CFA_WRITE_MULT_NE, 	"CFA WRITE MULTIPLE WITHOUT ERASE" },
2311 		{ ATA_CMD_READ_LONG,		"READ LONG (with retries)" },
2312 		{ ATA_CMD_READ_LONG_ONCE,	"READ LONG (without retries)" },
2313 		{ ATA_CMD_WRITE_LONG,		"WRITE LONG (with retries)" },
2314 		{ ATA_CMD_WRITE_LONG_ONCE,	"WRITE LONG (without retries)" },
2315 		{ ATA_CMD_RESTORE,		"RECALIBRATE" },
2316 		{ 0,				NULL } /* terminate list */
2317 	};
2318 
2319 	unsigned int i;
2320 	for (i = 0; cmd_descr[i].text; i++)
2321 		if (cmd_descr[i].command == command)
2322 			return cmd_descr[i].text;
2323 #endif
2324 
2325 	return NULL;
2326 }
2327 
2328 /**
2329  *	ata_eh_link_report - report error handling to user
2330  *	@link: ATA link EH is going on
2331  *
2332  *	Report EH to user.
2333  *
2334  *	LOCKING:
2335  *	None.
2336  */
2337 static void ata_eh_link_report(struct ata_link *link)
2338 {
2339 	struct ata_port *ap = link->ap;
2340 	struct ata_eh_context *ehc = &link->eh_context;
2341 	const char *frozen, *desc;
2342 	char tries_buf[6];
2343 	int tag, nr_failed = 0;
2344 
2345 	if (ehc->i.flags & ATA_EHI_QUIET)
2346 		return;
2347 
2348 	desc = NULL;
2349 	if (ehc->i.desc[0] != '\0')
2350 		desc = ehc->i.desc;
2351 
2352 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
2353 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
2354 
2355 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
2356 		    ata_dev_phys_link(qc->dev) != link ||
2357 		    ((qc->flags & ATA_QCFLAG_QUIET) &&
2358 		     qc->err_mask == AC_ERR_DEV))
2359 			continue;
2360 		if (qc->flags & ATA_QCFLAG_SENSE_VALID && !qc->err_mask)
2361 			continue;
2362 
2363 		nr_failed++;
2364 	}
2365 
2366 	if (!nr_failed && !ehc->i.err_mask)
2367 		return;
2368 
2369 	frozen = "";
2370 	if (ap->pflags & ATA_PFLAG_FROZEN)
2371 		frozen = " frozen";
2372 
2373 	memset(tries_buf, 0, sizeof(tries_buf));
2374 	if (ap->eh_tries < ATA_EH_MAX_TRIES)
2375 		snprintf(tries_buf, sizeof(tries_buf) - 1, " t%d",
2376 			 ap->eh_tries);
2377 
2378 	if (ehc->i.dev) {
2379 		ata_dev_err(ehc->i.dev, "exception Emask 0x%x "
2380 			    "SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
2381 			    ehc->i.err_mask, link->sactive, ehc->i.serror,
2382 			    ehc->i.action, frozen, tries_buf);
2383 		if (desc)
2384 			ata_dev_err(ehc->i.dev, "%s\n", desc);
2385 	} else {
2386 		ata_link_err(link, "exception Emask 0x%x "
2387 			     "SAct 0x%x SErr 0x%x action 0x%x%s%s\n",
2388 			     ehc->i.err_mask, link->sactive, ehc->i.serror,
2389 			     ehc->i.action, frozen, tries_buf);
2390 		if (desc)
2391 			ata_link_err(link, "%s\n", desc);
2392 	}
2393 
2394 #ifdef CONFIG_ATA_VERBOSE_ERROR
2395 	if (ehc->i.serror)
2396 		ata_link_err(link,
2397 		  "SError: { %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s}\n",
2398 		  ehc->i.serror & SERR_DATA_RECOVERED ? "RecovData " : "",
2399 		  ehc->i.serror & SERR_COMM_RECOVERED ? "RecovComm " : "",
2400 		  ehc->i.serror & SERR_DATA ? "UnrecovData " : "",
2401 		  ehc->i.serror & SERR_PERSISTENT ? "Persist " : "",
2402 		  ehc->i.serror & SERR_PROTOCOL ? "Proto " : "",
2403 		  ehc->i.serror & SERR_INTERNAL ? "HostInt " : "",
2404 		  ehc->i.serror & SERR_PHYRDY_CHG ? "PHYRdyChg " : "",
2405 		  ehc->i.serror & SERR_PHY_INT_ERR ? "PHYInt " : "",
2406 		  ehc->i.serror & SERR_COMM_WAKE ? "CommWake " : "",
2407 		  ehc->i.serror & SERR_10B_8B_ERR ? "10B8B " : "",
2408 		  ehc->i.serror & SERR_DISPARITY ? "Dispar " : "",
2409 		  ehc->i.serror & SERR_CRC ? "BadCRC " : "",
2410 		  ehc->i.serror & SERR_HANDSHAKE ? "Handshk " : "",
2411 		  ehc->i.serror & SERR_LINK_SEQ_ERR ? "LinkSeq " : "",
2412 		  ehc->i.serror & SERR_TRANS_ST_ERROR ? "TrStaTrns " : "",
2413 		  ehc->i.serror & SERR_UNRECOG_FIS ? "UnrecFIS " : "",
2414 		  ehc->i.serror & SERR_DEV_XCHG ? "DevExch " : "");
2415 #endif
2416 
2417 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
2418 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
2419 		struct ata_taskfile *cmd = &qc->tf, *res = &qc->result_tf;
2420 		const u8 *cdb = qc->cdb;
2421 		char data_buf[20] = "";
2422 		char cdb_buf[70] = "";
2423 
2424 		if (!(qc->flags & ATA_QCFLAG_FAILED) ||
2425 		    ata_dev_phys_link(qc->dev) != link || !qc->err_mask)
2426 			continue;
2427 
2428 		if (qc->dma_dir != DMA_NONE) {
2429 			static const char *dma_str[] = {
2430 				[DMA_BIDIRECTIONAL]	= "bidi",
2431 				[DMA_TO_DEVICE]		= "out",
2432 				[DMA_FROM_DEVICE]	= "in",
2433 			};
2434 			static const char *prot_str[] = {
2435 				[ATA_PROT_PIO]		= "pio",
2436 				[ATA_PROT_DMA]		= "dma",
2437 				[ATA_PROT_NCQ]		= "ncq",
2438 				[ATAPI_PROT_PIO]	= "pio",
2439 				[ATAPI_PROT_DMA]	= "dma",
2440 			};
2441 
2442 			snprintf(data_buf, sizeof(data_buf), " %s %u %s",
2443 				 prot_str[qc->tf.protocol], qc->nbytes,
2444 				 dma_str[qc->dma_dir]);
2445 		}
2446 
2447 		if (ata_is_atapi(qc->tf.protocol)) {
2448 			if (qc->scsicmd)
2449 				scsi_print_command(qc->scsicmd);
2450 			else
2451 				snprintf(cdb_buf, sizeof(cdb_buf),
2452 				 "cdb %02x %02x %02x %02x %02x %02x %02x %02x  "
2453 				 "%02x %02x %02x %02x %02x %02x %02x %02x\n         ",
2454 				 cdb[0], cdb[1], cdb[2], cdb[3],
2455 				 cdb[4], cdb[5], cdb[6], cdb[7],
2456 				 cdb[8], cdb[9], cdb[10], cdb[11],
2457 				 cdb[12], cdb[13], cdb[14], cdb[15]);
2458 		} else {
2459 			const char *descr = ata_get_cmd_descript(cmd->command);
2460 			if (descr)
2461 				ata_dev_err(qc->dev, "failed command: %s\n",
2462 					    descr);
2463 		}
2464 
2465 		ata_dev_err(qc->dev,
2466 			"cmd %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
2467 			"tag %d%s\n         %s"
2468 			"res %02x/%02x:%02x:%02x:%02x:%02x/%02x:%02x:%02x:%02x:%02x/%02x "
2469 			"Emask 0x%x (%s)%s\n",
2470 			cmd->command, cmd->feature, cmd->nsect,
2471 			cmd->lbal, cmd->lbam, cmd->lbah,
2472 			cmd->hob_feature, cmd->hob_nsect,
2473 			cmd->hob_lbal, cmd->hob_lbam, cmd->hob_lbah,
2474 			cmd->device, qc->tag, data_buf, cdb_buf,
2475 			res->command, res->feature, res->nsect,
2476 			res->lbal, res->lbam, res->lbah,
2477 			res->hob_feature, res->hob_nsect,
2478 			res->hob_lbal, res->hob_lbam, res->hob_lbah,
2479 			res->device, qc->err_mask, ata_err_string(qc->err_mask),
2480 			qc->err_mask & AC_ERR_NCQ ? " <F>" : "");
2481 
2482 #ifdef CONFIG_ATA_VERBOSE_ERROR
2483 		if (res->command & (ATA_BUSY | ATA_DRDY | ATA_DF | ATA_DRQ |
2484 				    ATA_ERR)) {
2485 			if (res->command & ATA_BUSY)
2486 				ata_dev_err(qc->dev, "status: { Busy }\n");
2487 			else
2488 				ata_dev_err(qc->dev, "status: { %s%s%s%s}\n",
2489 				  res->command & ATA_DRDY ? "DRDY " : "",
2490 				  res->command & ATA_DF ? "DF " : "",
2491 				  res->command & ATA_DRQ ? "DRQ " : "",
2492 				  res->command & ATA_ERR ? "ERR " : "");
2493 		}
2494 
2495 		if (cmd->command != ATA_CMD_PACKET &&
2496 		    (res->feature & (ATA_ICRC | ATA_UNC | ATA_IDNF |
2497 				     ATA_ABORTED)))
2498 			ata_dev_err(qc->dev, "error: { %s%s%s%s}\n",
2499 			  res->feature & ATA_ICRC ? "ICRC " : "",
2500 			  res->feature & ATA_UNC ? "UNC " : "",
2501 			  res->feature & ATA_IDNF ? "IDNF " : "",
2502 			  res->feature & ATA_ABORTED ? "ABRT " : "");
2503 #endif
2504 	}
2505 }
2506 
2507 /**
2508  *	ata_eh_report - report error handling to user
2509  *	@ap: ATA port to report EH about
2510  *
2511  *	Report EH to user.
2512  *
2513  *	LOCKING:
2514  *	None.
2515  */
2516 void ata_eh_report(struct ata_port *ap)
2517 {
2518 	struct ata_link *link;
2519 
2520 	ata_for_each_link(link, ap, HOST_FIRST)
2521 		ata_eh_link_report(link);
2522 }
2523 
2524 static int ata_do_reset(struct ata_link *link, ata_reset_fn_t reset,
2525 			unsigned int *classes, unsigned long deadline,
2526 			bool clear_classes)
2527 {
2528 	struct ata_device *dev;
2529 
2530 	if (clear_classes)
2531 		ata_for_each_dev(dev, link, ALL)
2532 			classes[dev->devno] = ATA_DEV_UNKNOWN;
2533 
2534 	return reset(link, classes, deadline);
2535 }
2536 
2537 static int ata_eh_followup_srst_needed(struct ata_link *link, int rc)
2538 {
2539 	if ((link->flags & ATA_LFLAG_NO_SRST) || ata_link_offline(link))
2540 		return 0;
2541 	if (rc == -EAGAIN)
2542 		return 1;
2543 	if (sata_pmp_supported(link->ap) && ata_is_host_link(link))
2544 		return 1;
2545 	return 0;
2546 }
2547 
2548 int ata_eh_reset(struct ata_link *link, int classify,
2549 		 ata_prereset_fn_t prereset, ata_reset_fn_t softreset,
2550 		 ata_reset_fn_t hardreset, ata_postreset_fn_t postreset)
2551 {
2552 	struct ata_port *ap = link->ap;
2553 	struct ata_link *slave = ap->slave_link;
2554 	struct ata_eh_context *ehc = &link->eh_context;
2555 	struct ata_eh_context *sehc = slave ? &slave->eh_context : NULL;
2556 	unsigned int *classes = ehc->classes;
2557 	unsigned int lflags = link->flags;
2558 	int verbose = !(ehc->i.flags & ATA_EHI_QUIET);
2559 	int max_tries = 0, try = 0;
2560 	struct ata_link *failed_link;
2561 	struct ata_device *dev;
2562 	unsigned long deadline, now;
2563 	ata_reset_fn_t reset;
2564 	unsigned long flags;
2565 	u32 sstatus;
2566 	int nr_unknown, rc;
2567 
2568 	/*
2569 	 * Prepare to reset
2570 	 */
2571 	while (ata_eh_reset_timeouts[max_tries] != ULONG_MAX)
2572 		max_tries++;
2573 	if (link->flags & ATA_LFLAG_NO_HRST)
2574 		hardreset = NULL;
2575 	if (link->flags & ATA_LFLAG_NO_SRST)
2576 		softreset = NULL;
2577 
2578 	/* make sure each reset attempt is at least COOL_DOWN apart */
2579 	if (ehc->i.flags & ATA_EHI_DID_RESET) {
2580 		now = jiffies;
2581 		WARN_ON(time_after(ehc->last_reset, now));
2582 		deadline = ata_deadline(ehc->last_reset,
2583 					ATA_EH_RESET_COOL_DOWN);
2584 		if (time_before(now, deadline))
2585 			schedule_timeout_uninterruptible(deadline - now);
2586 	}
2587 
2588 	spin_lock_irqsave(ap->lock, flags);
2589 	ap->pflags |= ATA_PFLAG_RESETTING;
2590 	spin_unlock_irqrestore(ap->lock, flags);
2591 
2592 	ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
2593 
2594 	ata_for_each_dev(dev, link, ALL) {
2595 		/* If we issue an SRST then an ATA drive (not ATAPI)
2596 		 * may change configuration and be in PIO0 timing. If
2597 		 * we do a hard reset (or are coming from power on)
2598 		 * this is true for ATA or ATAPI. Until we've set a
2599 		 * suitable controller mode we should not touch the
2600 		 * bus as we may be talking too fast.
2601 		 */
2602 		dev->pio_mode = XFER_PIO_0;
2603 
2604 		/* If the controller has a pio mode setup function
2605 		 * then use it to set the chipset to rights. Don't
2606 		 * touch the DMA setup as that will be dealt with when
2607 		 * configuring devices.
2608 		 */
2609 		if (ap->ops->set_piomode)
2610 			ap->ops->set_piomode(ap, dev);
2611 	}
2612 
2613 	/* prefer hardreset */
2614 	reset = NULL;
2615 	ehc->i.action &= ~ATA_EH_RESET;
2616 	if (hardreset) {
2617 		reset = hardreset;
2618 		ehc->i.action |= ATA_EH_HARDRESET;
2619 	} else if (softreset) {
2620 		reset = softreset;
2621 		ehc->i.action |= ATA_EH_SOFTRESET;
2622 	}
2623 
2624 	if (prereset) {
2625 		unsigned long deadline = ata_deadline(jiffies,
2626 						      ATA_EH_PRERESET_TIMEOUT);
2627 
2628 		if (slave) {
2629 			sehc->i.action &= ~ATA_EH_RESET;
2630 			sehc->i.action |= ehc->i.action;
2631 		}
2632 
2633 		rc = prereset(link, deadline);
2634 
2635 		/* If present, do prereset on slave link too.  Reset
2636 		 * is skipped iff both master and slave links report
2637 		 * -ENOENT or clear ATA_EH_RESET.
2638 		 */
2639 		if (slave && (rc == 0 || rc == -ENOENT)) {
2640 			int tmp;
2641 
2642 			tmp = prereset(slave, deadline);
2643 			if (tmp != -ENOENT)
2644 				rc = tmp;
2645 
2646 			ehc->i.action |= sehc->i.action;
2647 		}
2648 
2649 		if (rc) {
2650 			if (rc == -ENOENT) {
2651 				ata_link_dbg(link, "port disabled--ignoring\n");
2652 				ehc->i.action &= ~ATA_EH_RESET;
2653 
2654 				ata_for_each_dev(dev, link, ALL)
2655 					classes[dev->devno] = ATA_DEV_NONE;
2656 
2657 				rc = 0;
2658 			} else
2659 				ata_link_err(link,
2660 					     "prereset failed (errno=%d)\n",
2661 					     rc);
2662 			goto out;
2663 		}
2664 
2665 		/* prereset() might have cleared ATA_EH_RESET.  If so,
2666 		 * bang classes, thaw and return.
2667 		 */
2668 		if (reset && !(ehc->i.action & ATA_EH_RESET)) {
2669 			ata_for_each_dev(dev, link, ALL)
2670 				classes[dev->devno] = ATA_DEV_NONE;
2671 			if ((ap->pflags & ATA_PFLAG_FROZEN) &&
2672 			    ata_is_host_link(link))
2673 				ata_eh_thaw_port(ap);
2674 			rc = 0;
2675 			goto out;
2676 		}
2677 	}
2678 
2679  retry:
2680 	/*
2681 	 * Perform reset
2682 	 */
2683 	if (ata_is_host_link(link))
2684 		ata_eh_freeze_port(ap);
2685 
2686 	deadline = ata_deadline(jiffies, ata_eh_reset_timeouts[try++]);
2687 
2688 	if (reset) {
2689 		if (verbose)
2690 			ata_link_info(link, "%s resetting link\n",
2691 				      reset == softreset ? "soft" : "hard");
2692 
2693 		/* mark that this EH session started with reset */
2694 		ehc->last_reset = jiffies;
2695 		if (reset == hardreset)
2696 			ehc->i.flags |= ATA_EHI_DID_HARDRESET;
2697 		else
2698 			ehc->i.flags |= ATA_EHI_DID_SOFTRESET;
2699 
2700 		rc = ata_do_reset(link, reset, classes, deadline, true);
2701 		if (rc && rc != -EAGAIN) {
2702 			failed_link = link;
2703 			goto fail;
2704 		}
2705 
2706 		/* hardreset slave link if existent */
2707 		if (slave && reset == hardreset) {
2708 			int tmp;
2709 
2710 			if (verbose)
2711 				ata_link_info(slave, "hard resetting link\n");
2712 
2713 			ata_eh_about_to_do(slave, NULL, ATA_EH_RESET);
2714 			tmp = ata_do_reset(slave, reset, classes, deadline,
2715 					   false);
2716 			switch (tmp) {
2717 			case -EAGAIN:
2718 				rc = -EAGAIN;
2719 			case 0:
2720 				break;
2721 			default:
2722 				failed_link = slave;
2723 				rc = tmp;
2724 				goto fail;
2725 			}
2726 		}
2727 
2728 		/* perform follow-up SRST if necessary */
2729 		if (reset == hardreset &&
2730 		    ata_eh_followup_srst_needed(link, rc)) {
2731 			reset = softreset;
2732 
2733 			if (!reset) {
2734 				ata_link_err(link,
2735 	     "follow-up softreset required but no softreset available\n");
2736 				failed_link = link;
2737 				rc = -EINVAL;
2738 				goto fail;
2739 			}
2740 
2741 			ata_eh_about_to_do(link, NULL, ATA_EH_RESET);
2742 			rc = ata_do_reset(link, reset, classes, deadline, true);
2743 			if (rc) {
2744 				failed_link = link;
2745 				goto fail;
2746 			}
2747 		}
2748 	} else {
2749 		if (verbose)
2750 			ata_link_info(link,
2751 	"no reset method available, skipping reset\n");
2752 		if (!(lflags & ATA_LFLAG_ASSUME_CLASS))
2753 			lflags |= ATA_LFLAG_ASSUME_ATA;
2754 	}
2755 
2756 	/*
2757 	 * Post-reset processing
2758 	 */
2759 	ata_for_each_dev(dev, link, ALL) {
2760 		/* After the reset, the device state is PIO 0 and the
2761 		 * controller state is undefined.  Reset also wakes up
2762 		 * drives from sleeping mode.
2763 		 */
2764 		dev->pio_mode = XFER_PIO_0;
2765 		dev->flags &= ~ATA_DFLAG_SLEEPING;
2766 
2767 		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
2768 			continue;
2769 
2770 		/* apply class override */
2771 		if (lflags & ATA_LFLAG_ASSUME_ATA)
2772 			classes[dev->devno] = ATA_DEV_ATA;
2773 		else if (lflags & ATA_LFLAG_ASSUME_SEMB)
2774 			classes[dev->devno] = ATA_DEV_SEMB_UNSUP;
2775 	}
2776 
2777 	/* record current link speed */
2778 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0)
2779 		link->sata_spd = (sstatus >> 4) & 0xf;
2780 	if (slave && sata_scr_read(slave, SCR_STATUS, &sstatus) == 0)
2781 		slave->sata_spd = (sstatus >> 4) & 0xf;
2782 
2783 	/* thaw the port */
2784 	if (ata_is_host_link(link))
2785 		ata_eh_thaw_port(ap);
2786 
2787 	/* postreset() should clear hardware SError.  Although SError
2788 	 * is cleared during link resume, clearing SError here is
2789 	 * necessary as some PHYs raise hotplug events after SRST.
2790 	 * This introduces race condition where hotplug occurs between
2791 	 * reset and here.  This race is mediated by cross checking
2792 	 * link onlineness and classification result later.
2793 	 */
2794 	if (postreset) {
2795 		postreset(link, classes);
2796 		if (slave)
2797 			postreset(slave, classes);
2798 	}
2799 
2800 	/*
2801 	 * Some controllers can't be frozen very well and may set spurious
2802 	 * error conditions during reset.  Clear accumulated error
2803 	 * information and re-thaw the port if frozen.  As reset is the
2804 	 * final recovery action and we cross check link onlineness against
2805 	 * device classification later, no hotplug event is lost by this.
2806 	 */
2807 	spin_lock_irqsave(link->ap->lock, flags);
2808 	memset(&link->eh_info, 0, sizeof(link->eh_info));
2809 	if (slave)
2810 		memset(&slave->eh_info, 0, sizeof(link->eh_info));
2811 	ap->pflags &= ~ATA_PFLAG_EH_PENDING;
2812 	spin_unlock_irqrestore(link->ap->lock, flags);
2813 
2814 	if (ap->pflags & ATA_PFLAG_FROZEN)
2815 		ata_eh_thaw_port(ap);
2816 
2817 	/*
2818 	 * Make sure onlineness and classification result correspond.
2819 	 * Hotplug could have happened during reset and some
2820 	 * controllers fail to wait while a drive is spinning up after
2821 	 * being hotplugged causing misdetection.  By cross checking
2822 	 * link on/offlineness and classification result, those
2823 	 * conditions can be reliably detected and retried.
2824 	 */
2825 	nr_unknown = 0;
2826 	ata_for_each_dev(dev, link, ALL) {
2827 		if (ata_phys_link_online(ata_dev_phys_link(dev))) {
2828 			if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
2829 				ata_dev_dbg(dev, "link online but device misclassified\n");
2830 				classes[dev->devno] = ATA_DEV_NONE;
2831 				nr_unknown++;
2832 			}
2833 		} else if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
2834 			if (ata_class_enabled(classes[dev->devno]))
2835 				ata_dev_dbg(dev,
2836 					    "link offline, clearing class %d to NONE\n",
2837 					    classes[dev->devno]);
2838 			classes[dev->devno] = ATA_DEV_NONE;
2839 		} else if (classes[dev->devno] == ATA_DEV_UNKNOWN) {
2840 			ata_dev_dbg(dev,
2841 				    "link status unknown, clearing UNKNOWN to NONE\n");
2842 			classes[dev->devno] = ATA_DEV_NONE;
2843 		}
2844 	}
2845 
2846 	if (classify && nr_unknown) {
2847 		if (try < max_tries) {
2848 			ata_link_warn(link,
2849 				      "link online but %d devices misclassified, retrying\n",
2850 				      nr_unknown);
2851 			failed_link = link;
2852 			rc = -EAGAIN;
2853 			goto fail;
2854 		}
2855 		ata_link_warn(link,
2856 			      "link online but %d devices misclassified, "
2857 			      "device detection might fail\n", nr_unknown);
2858 	}
2859 
2860 	/* reset successful, schedule revalidation */
2861 	ata_eh_done(link, NULL, ATA_EH_RESET);
2862 	if (slave)
2863 		ata_eh_done(slave, NULL, ATA_EH_RESET);
2864 	ehc->last_reset = jiffies;		/* update to completion time */
2865 	ehc->i.action |= ATA_EH_REVALIDATE;
2866 	link->lpm_policy = ATA_LPM_UNKNOWN;	/* reset LPM state */
2867 
2868 	rc = 0;
2869  out:
2870 	/* clear hotplug flag */
2871 	ehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
2872 	if (slave)
2873 		sehc->i.flags &= ~ATA_EHI_HOTPLUGGED;
2874 
2875 	spin_lock_irqsave(ap->lock, flags);
2876 	ap->pflags &= ~ATA_PFLAG_RESETTING;
2877 	spin_unlock_irqrestore(ap->lock, flags);
2878 
2879 	return rc;
2880 
2881  fail:
2882 	/* if SCR isn't accessible on a fan-out port, PMP needs to be reset */
2883 	if (!ata_is_host_link(link) &&
2884 	    sata_scr_read(link, SCR_STATUS, &sstatus))
2885 		rc = -ERESTART;
2886 
2887 	if (try >= max_tries) {
2888 		/*
2889 		 * Thaw host port even if reset failed, so that the port
2890 		 * can be retried on the next phy event.  This risks
2891 		 * repeated EH runs but seems to be a better tradeoff than
2892 		 * shutting down a port after a botched hotplug attempt.
2893 		 */
2894 		if (ata_is_host_link(link))
2895 			ata_eh_thaw_port(ap);
2896 		goto out;
2897 	}
2898 
2899 	now = jiffies;
2900 	if (time_before(now, deadline)) {
2901 		unsigned long delta = deadline - now;
2902 
2903 		ata_link_warn(failed_link,
2904 			"reset failed (errno=%d), retrying in %u secs\n",
2905 			rc, DIV_ROUND_UP(jiffies_to_msecs(delta), 1000));
2906 
2907 		ata_eh_release(ap);
2908 		while (delta)
2909 			delta = schedule_timeout_uninterruptible(delta);
2910 		ata_eh_acquire(ap);
2911 	}
2912 
2913 	/*
2914 	 * While disks spinup behind PMP, some controllers fail sending SRST.
2915 	 * They need to be reset - as well as the PMP - before retrying.
2916 	 */
2917 	if (rc == -ERESTART) {
2918 		if (ata_is_host_link(link))
2919 			ata_eh_thaw_port(ap);
2920 		goto out;
2921 	}
2922 
2923 	if (try == max_tries - 1) {
2924 		sata_down_spd_limit(link, 0);
2925 		if (slave)
2926 			sata_down_spd_limit(slave, 0);
2927 	} else if (rc == -EPIPE)
2928 		sata_down_spd_limit(failed_link, 0);
2929 
2930 	if (hardreset)
2931 		reset = hardreset;
2932 	goto retry;
2933 }
2934 
2935 static inline void ata_eh_pull_park_action(struct ata_port *ap)
2936 {
2937 	struct ata_link *link;
2938 	struct ata_device *dev;
2939 	unsigned long flags;
2940 
2941 	/*
2942 	 * This function can be thought of as an extended version of
2943 	 * ata_eh_about_to_do() specially crafted to accommodate the
2944 	 * requirements of ATA_EH_PARK handling. Since the EH thread
2945 	 * does not leave the do {} while () loop in ata_eh_recover as
2946 	 * long as the timeout for a park request to *one* device on
2947 	 * the port has not expired, and since we still want to pick
2948 	 * up park requests to other devices on the same port or
2949 	 * timeout updates for the same device, we have to pull
2950 	 * ATA_EH_PARK actions from eh_info into eh_context.i
2951 	 * ourselves at the beginning of each pass over the loop.
2952 	 *
2953 	 * Additionally, all write accesses to &ap->park_req_pending
2954 	 * through INIT_COMPLETION() (see below) or complete_all()
2955 	 * (see ata_scsi_park_store()) are protected by the host lock.
2956 	 * As a result we have that park_req_pending.done is zero on
2957 	 * exit from this function, i.e. when ATA_EH_PARK actions for
2958 	 * *all* devices on port ap have been pulled into the
2959 	 * respective eh_context structs. If, and only if,
2960 	 * park_req_pending.done is non-zero by the time we reach
2961 	 * wait_for_completion_timeout(), another ATA_EH_PARK action
2962 	 * has been scheduled for at least one of the devices on port
2963 	 * ap and we have to cycle over the do {} while () loop in
2964 	 * ata_eh_recover() again.
2965 	 */
2966 
2967 	spin_lock_irqsave(ap->lock, flags);
2968 	INIT_COMPLETION(ap->park_req_pending);
2969 	ata_for_each_link(link, ap, EDGE) {
2970 		ata_for_each_dev(dev, link, ALL) {
2971 			struct ata_eh_info *ehi = &link->eh_info;
2972 
2973 			link->eh_context.i.dev_action[dev->devno] |=
2974 				ehi->dev_action[dev->devno] & ATA_EH_PARK;
2975 			ata_eh_clear_action(link, dev, ehi, ATA_EH_PARK);
2976 		}
2977 	}
2978 	spin_unlock_irqrestore(ap->lock, flags);
2979 }
2980 
2981 static void ata_eh_park_issue_cmd(struct ata_device *dev, int park)
2982 {
2983 	struct ata_eh_context *ehc = &dev->link->eh_context;
2984 	struct ata_taskfile tf;
2985 	unsigned int err_mask;
2986 
2987 	ata_tf_init(dev, &tf);
2988 	if (park) {
2989 		ehc->unloaded_mask |= 1 << dev->devno;
2990 		tf.command = ATA_CMD_IDLEIMMEDIATE;
2991 		tf.feature = 0x44;
2992 		tf.lbal = 0x4c;
2993 		tf.lbam = 0x4e;
2994 		tf.lbah = 0x55;
2995 	} else {
2996 		ehc->unloaded_mask &= ~(1 << dev->devno);
2997 		tf.command = ATA_CMD_CHK_POWER;
2998 	}
2999 
3000 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
3001 	tf.protocol |= ATA_PROT_NODATA;
3002 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
3003 	if (park && (err_mask || tf.lbal != 0xc4)) {
3004 		ata_dev_err(dev, "head unload failed!\n");
3005 		ehc->unloaded_mask &= ~(1 << dev->devno);
3006 	}
3007 }
3008 
3009 static int ata_eh_revalidate_and_attach(struct ata_link *link,
3010 					struct ata_device **r_failed_dev)
3011 {
3012 	struct ata_port *ap = link->ap;
3013 	struct ata_eh_context *ehc = &link->eh_context;
3014 	struct ata_device *dev;
3015 	unsigned int new_mask = 0;
3016 	unsigned long flags;
3017 	int rc = 0;
3018 
3019 	DPRINTK("ENTER\n");
3020 
3021 	/* For PATA drive side cable detection to work, IDENTIFY must
3022 	 * be done backwards such that PDIAG- is released by the slave
3023 	 * device before the master device is identified.
3024 	 */
3025 	ata_for_each_dev(dev, link, ALL_REVERSE) {
3026 		unsigned int action = ata_eh_dev_action(dev);
3027 		unsigned int readid_flags = 0;
3028 
3029 		if (ehc->i.flags & ATA_EHI_DID_RESET)
3030 			readid_flags |= ATA_READID_POSTRESET;
3031 
3032 		if ((action & ATA_EH_REVALIDATE) && ata_dev_enabled(dev)) {
3033 			WARN_ON(dev->class == ATA_DEV_PMP);
3034 
3035 			if (ata_phys_link_offline(ata_dev_phys_link(dev))) {
3036 				rc = -EIO;
3037 				goto err;
3038 			}
3039 
3040 			ata_eh_about_to_do(link, dev, ATA_EH_REVALIDATE);
3041 			rc = ata_dev_revalidate(dev, ehc->classes[dev->devno],
3042 						readid_flags);
3043 			if (rc)
3044 				goto err;
3045 
3046 			ata_eh_done(link, dev, ATA_EH_REVALIDATE);
3047 
3048 			/* Configuration may have changed, reconfigure
3049 			 * transfer mode.
3050 			 */
3051 			ehc->i.flags |= ATA_EHI_SETMODE;
3052 
3053 			/* schedule the scsi_rescan_device() here */
3054 			schedule_work(&(ap->scsi_rescan_task));
3055 		} else if (dev->class == ATA_DEV_UNKNOWN &&
3056 			   ehc->tries[dev->devno] &&
3057 			   ata_class_enabled(ehc->classes[dev->devno])) {
3058 			/* Temporarily set dev->class, it will be
3059 			 * permanently set once all configurations are
3060 			 * complete.  This is necessary because new
3061 			 * device configuration is done in two
3062 			 * separate loops.
3063 			 */
3064 			dev->class = ehc->classes[dev->devno];
3065 
3066 			if (dev->class == ATA_DEV_PMP)
3067 				rc = sata_pmp_attach(dev);
3068 			else
3069 				rc = ata_dev_read_id(dev, &dev->class,
3070 						     readid_flags, dev->id);
3071 
3072 			/* read_id might have changed class, store and reset */
3073 			ehc->classes[dev->devno] = dev->class;
3074 			dev->class = ATA_DEV_UNKNOWN;
3075 
3076 			switch (rc) {
3077 			case 0:
3078 				/* clear error info accumulated during probe */
3079 				ata_ering_clear(&dev->ering);
3080 				new_mask |= 1 << dev->devno;
3081 				break;
3082 			case -ENOENT:
3083 				/* IDENTIFY was issued to non-existent
3084 				 * device.  No need to reset.  Just
3085 				 * thaw and ignore the device.
3086 				 */
3087 				ata_eh_thaw_port(ap);
3088 				break;
3089 			default:
3090 				goto err;
3091 			}
3092 		}
3093 	}
3094 
3095 	/* PDIAG- should have been released, ask cable type if post-reset */
3096 	if ((ehc->i.flags & ATA_EHI_DID_RESET) && ata_is_host_link(link)) {
3097 		if (ap->ops->cable_detect)
3098 			ap->cbl = ap->ops->cable_detect(ap);
3099 		ata_force_cbl(ap);
3100 	}
3101 
3102 	/* Configure new devices forward such that user doesn't see
3103 	 * device detection messages backwards.
3104 	 */
3105 	ata_for_each_dev(dev, link, ALL) {
3106 		if (!(new_mask & (1 << dev->devno)))
3107 			continue;
3108 
3109 		dev->class = ehc->classes[dev->devno];
3110 
3111 		if (dev->class == ATA_DEV_PMP)
3112 			continue;
3113 
3114 		ehc->i.flags |= ATA_EHI_PRINTINFO;
3115 		rc = ata_dev_configure(dev);
3116 		ehc->i.flags &= ~ATA_EHI_PRINTINFO;
3117 		if (rc) {
3118 			dev->class = ATA_DEV_UNKNOWN;
3119 			goto err;
3120 		}
3121 
3122 		spin_lock_irqsave(ap->lock, flags);
3123 		ap->pflags |= ATA_PFLAG_SCSI_HOTPLUG;
3124 		spin_unlock_irqrestore(ap->lock, flags);
3125 
3126 		/* new device discovered, configure xfermode */
3127 		ehc->i.flags |= ATA_EHI_SETMODE;
3128 	}
3129 
3130 	return 0;
3131 
3132  err:
3133 	*r_failed_dev = dev;
3134 	DPRINTK("EXIT rc=%d\n", rc);
3135 	return rc;
3136 }
3137 
3138 /**
3139  *	ata_set_mode - Program timings and issue SET FEATURES - XFER
3140  *	@link: link on which timings will be programmed
3141  *	@r_failed_dev: out parameter for failed device
3142  *
3143  *	Set ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
3144  *	ata_set_mode() fails, pointer to the failing device is
3145  *	returned in @r_failed_dev.
3146  *
3147  *	LOCKING:
3148  *	PCI/etc. bus probe sem.
3149  *
3150  *	RETURNS:
3151  *	0 on success, negative errno otherwise
3152  */
3153 int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3154 {
3155 	struct ata_port *ap = link->ap;
3156 	struct ata_device *dev;
3157 	int rc;
3158 
3159 	/* if data transfer is verified, clear DUBIOUS_XFER on ering top */
3160 	ata_for_each_dev(dev, link, ENABLED) {
3161 		if (!(dev->flags & ATA_DFLAG_DUBIOUS_XFER)) {
3162 			struct ata_ering_entry *ent;
3163 
3164 			ent = ata_ering_top(&dev->ering);
3165 			if (ent)
3166 				ent->eflags &= ~ATA_EFLAG_DUBIOUS_XFER;
3167 		}
3168 	}
3169 
3170 	/* has private set_mode? */
3171 	if (ap->ops->set_mode)
3172 		rc = ap->ops->set_mode(link, r_failed_dev);
3173 	else
3174 		rc = ata_do_set_mode(link, r_failed_dev);
3175 
3176 	/* if transfer mode has changed, set DUBIOUS_XFER on device */
3177 	ata_for_each_dev(dev, link, ENABLED) {
3178 		struct ata_eh_context *ehc = &link->eh_context;
3179 		u8 saved_xfer_mode = ehc->saved_xfer_mode[dev->devno];
3180 		u8 saved_ncq = !!(ehc->saved_ncq_enabled & (1 << dev->devno));
3181 
3182 		if (dev->xfer_mode != saved_xfer_mode ||
3183 		    ata_ncq_enabled(dev) != saved_ncq)
3184 			dev->flags |= ATA_DFLAG_DUBIOUS_XFER;
3185 	}
3186 
3187 	return rc;
3188 }
3189 
3190 /**
3191  *	atapi_eh_clear_ua - Clear ATAPI UNIT ATTENTION after reset
3192  *	@dev: ATAPI device to clear UA for
3193  *
3194  *	Resets and other operations can make an ATAPI device raise
3195  *	UNIT ATTENTION which causes the next operation to fail.  This
3196  *	function clears UA.
3197  *
3198  *	LOCKING:
3199  *	EH context (may sleep).
3200  *
3201  *	RETURNS:
3202  *	0 on success, -errno on failure.
3203  */
3204 static int atapi_eh_clear_ua(struct ata_device *dev)
3205 {
3206 	int i;
3207 
3208 	for (i = 0; i < ATA_EH_UA_TRIES; i++) {
3209 		u8 *sense_buffer = dev->link->ap->sector_buf;
3210 		u8 sense_key = 0;
3211 		unsigned int err_mask;
3212 
3213 		err_mask = atapi_eh_tur(dev, &sense_key);
3214 		if (err_mask != 0 && err_mask != AC_ERR_DEV) {
3215 			ata_dev_warn(dev,
3216 				     "TEST_UNIT_READY failed (err_mask=0x%x)\n",
3217 				     err_mask);
3218 			return -EIO;
3219 		}
3220 
3221 		if (!err_mask || sense_key != UNIT_ATTENTION)
3222 			return 0;
3223 
3224 		err_mask = atapi_eh_request_sense(dev, sense_buffer, sense_key);
3225 		if (err_mask) {
3226 			ata_dev_warn(dev, "failed to clear "
3227 				"UNIT ATTENTION (err_mask=0x%x)\n", err_mask);
3228 			return -EIO;
3229 		}
3230 	}
3231 
3232 	ata_dev_warn(dev, "UNIT ATTENTION persists after %d tries\n",
3233 		     ATA_EH_UA_TRIES);
3234 
3235 	return 0;
3236 }
3237 
3238 /**
3239  *	ata_eh_maybe_retry_flush - Retry FLUSH if necessary
3240  *	@dev: ATA device which may need FLUSH retry
3241  *
3242  *	If @dev failed FLUSH, it needs to be reported upper layer
3243  *	immediately as it means that @dev failed to remap and already
3244  *	lost at least a sector and further FLUSH retrials won't make
3245  *	any difference to the lost sector.  However, if FLUSH failed
3246  *	for other reasons, for example transmission error, FLUSH needs
3247  *	to be retried.
3248  *
3249  *	This function determines whether FLUSH failure retry is
3250  *	necessary and performs it if so.
3251  *
3252  *	RETURNS:
3253  *	0 if EH can continue, -errno if EH needs to be repeated.
3254  */
3255 static int ata_eh_maybe_retry_flush(struct ata_device *dev)
3256 {
3257 	struct ata_link *link = dev->link;
3258 	struct ata_port *ap = link->ap;
3259 	struct ata_queued_cmd *qc;
3260 	struct ata_taskfile tf;
3261 	unsigned int err_mask;
3262 	int rc = 0;
3263 
3264 	/* did flush fail for this device? */
3265 	if (!ata_tag_valid(link->active_tag))
3266 		return 0;
3267 
3268 	qc = __ata_qc_from_tag(ap, link->active_tag);
3269 	if (qc->dev != dev || (qc->tf.command != ATA_CMD_FLUSH_EXT &&
3270 			       qc->tf.command != ATA_CMD_FLUSH))
3271 		return 0;
3272 
3273 	/* if the device failed it, it should be reported to upper layers */
3274 	if (qc->err_mask & AC_ERR_DEV)
3275 		return 0;
3276 
3277 	/* flush failed for some other reason, give it another shot */
3278 	ata_tf_init(dev, &tf);
3279 
3280 	tf.command = qc->tf.command;
3281 	tf.flags |= ATA_TFLAG_DEVICE;
3282 	tf.protocol = ATA_PROT_NODATA;
3283 
3284 	ata_dev_warn(dev, "retrying FLUSH 0x%x Emask 0x%x\n",
3285 		       tf.command, qc->err_mask);
3286 
3287 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
3288 	if (!err_mask) {
3289 		/*
3290 		 * FLUSH is complete but there's no way to
3291 		 * successfully complete a failed command from EH.
3292 		 * Making sure retry is allowed at least once and
3293 		 * retrying it should do the trick - whatever was in
3294 		 * the cache is already on the platter and this won't
3295 		 * cause infinite loop.
3296 		 */
3297 		qc->scsicmd->allowed = max(qc->scsicmd->allowed, 1);
3298 	} else {
3299 		ata_dev_warn(dev, "FLUSH failed Emask 0x%x\n",
3300 			       err_mask);
3301 		rc = -EIO;
3302 
3303 		/* if device failed it, report it to upper layers */
3304 		if (err_mask & AC_ERR_DEV) {
3305 			qc->err_mask |= AC_ERR_DEV;
3306 			qc->result_tf = tf;
3307 			if (!(ap->pflags & ATA_PFLAG_FROZEN))
3308 				rc = 0;
3309 		}
3310 	}
3311 	return rc;
3312 }
3313 
3314 /**
3315  *	ata_eh_set_lpm - configure SATA interface power management
3316  *	@link: link to configure power management
3317  *	@policy: the link power management policy
3318  *	@r_failed_dev: out parameter for failed device
3319  *
3320  *	Enable SATA Interface power management.  This will enable
3321  *	Device Interface Power Management (DIPM) for min_power
3322  * 	policy, and then call driver specific callbacks for
3323  *	enabling Host Initiated Power management.
3324  *
3325  *	LOCKING:
3326  *	EH context.
3327  *
3328  *	RETURNS:
3329  *	0 on success, -errno on failure.
3330  */
3331 static int ata_eh_set_lpm(struct ata_link *link, enum ata_lpm_policy policy,
3332 			  struct ata_device **r_failed_dev)
3333 {
3334 	struct ata_port *ap = ata_is_host_link(link) ? link->ap : NULL;
3335 	struct ata_eh_context *ehc = &link->eh_context;
3336 	struct ata_device *dev, *link_dev = NULL, *lpm_dev = NULL;
3337 	enum ata_lpm_policy old_policy = link->lpm_policy;
3338 	bool no_dipm = link->ap->flags & ATA_FLAG_NO_DIPM;
3339 	unsigned int hints = ATA_LPM_EMPTY | ATA_LPM_HIPM;
3340 	unsigned int err_mask;
3341 	int rc;
3342 
3343 	/* if the link or host doesn't do LPM, noop */
3344 	if ((link->flags & ATA_LFLAG_NO_LPM) || (ap && !ap->ops->set_lpm))
3345 		return 0;
3346 
3347 	/*
3348 	 * DIPM is enabled only for MIN_POWER as some devices
3349 	 * misbehave when the host NACKs transition to SLUMBER.  Order
3350 	 * device and link configurations such that the host always
3351 	 * allows DIPM requests.
3352 	 */
3353 	ata_for_each_dev(dev, link, ENABLED) {
3354 		bool hipm = ata_id_has_hipm(dev->id);
3355 		bool dipm = ata_id_has_dipm(dev->id) && !no_dipm;
3356 
3357 		/* find the first enabled and LPM enabled devices */
3358 		if (!link_dev)
3359 			link_dev = dev;
3360 
3361 		if (!lpm_dev && (hipm || dipm))
3362 			lpm_dev = dev;
3363 
3364 		hints &= ~ATA_LPM_EMPTY;
3365 		if (!hipm)
3366 			hints &= ~ATA_LPM_HIPM;
3367 
3368 		/* disable DIPM before changing link config */
3369 		if (policy != ATA_LPM_MIN_POWER && dipm) {
3370 			err_mask = ata_dev_set_feature(dev,
3371 					SETFEATURES_SATA_DISABLE, SATA_DIPM);
3372 			if (err_mask && err_mask != AC_ERR_DEV) {
3373 				ata_dev_warn(dev,
3374 					     "failed to disable DIPM, Emask 0x%x\n",
3375 					     err_mask);
3376 				rc = -EIO;
3377 				goto fail;
3378 			}
3379 		}
3380 	}
3381 
3382 	if (ap) {
3383 		rc = ap->ops->set_lpm(link, policy, hints);
3384 		if (!rc && ap->slave_link)
3385 			rc = ap->ops->set_lpm(ap->slave_link, policy, hints);
3386 	} else
3387 		rc = sata_pmp_set_lpm(link, policy, hints);
3388 
3389 	/*
3390 	 * Attribute link config failure to the first (LPM) enabled
3391 	 * device on the link.
3392 	 */
3393 	if (rc) {
3394 		if (rc == -EOPNOTSUPP) {
3395 			link->flags |= ATA_LFLAG_NO_LPM;
3396 			return 0;
3397 		}
3398 		dev = lpm_dev ? lpm_dev : link_dev;
3399 		goto fail;
3400 	}
3401 
3402 	/*
3403 	 * Low level driver acked the transition.  Issue DIPM command
3404 	 * with the new policy set.
3405 	 */
3406 	link->lpm_policy = policy;
3407 	if (ap && ap->slave_link)
3408 		ap->slave_link->lpm_policy = policy;
3409 
3410 	/* host config updated, enable DIPM if transitioning to MIN_POWER */
3411 	ata_for_each_dev(dev, link, ENABLED) {
3412 		if (policy == ATA_LPM_MIN_POWER && !no_dipm &&
3413 		    ata_id_has_dipm(dev->id)) {
3414 			err_mask = ata_dev_set_feature(dev,
3415 					SETFEATURES_SATA_ENABLE, SATA_DIPM);
3416 			if (err_mask && err_mask != AC_ERR_DEV) {
3417 				ata_dev_warn(dev,
3418 					"failed to enable DIPM, Emask 0x%x\n",
3419 					err_mask);
3420 				rc = -EIO;
3421 				goto fail;
3422 			}
3423 		}
3424 	}
3425 
3426 	return 0;
3427 
3428 fail:
3429 	/* restore the old policy */
3430 	link->lpm_policy = old_policy;
3431 	if (ap && ap->slave_link)
3432 		ap->slave_link->lpm_policy = old_policy;
3433 
3434 	/* if no device or only one more chance is left, disable LPM */
3435 	if (!dev || ehc->tries[dev->devno] <= 2) {
3436 		ata_link_warn(link, "disabling LPM on the link\n");
3437 		link->flags |= ATA_LFLAG_NO_LPM;
3438 	}
3439 	if (r_failed_dev)
3440 		*r_failed_dev = dev;
3441 	return rc;
3442 }
3443 
3444 int ata_link_nr_enabled(struct ata_link *link)
3445 {
3446 	struct ata_device *dev;
3447 	int cnt = 0;
3448 
3449 	ata_for_each_dev(dev, link, ENABLED)
3450 		cnt++;
3451 	return cnt;
3452 }
3453 
3454 static int ata_link_nr_vacant(struct ata_link *link)
3455 {
3456 	struct ata_device *dev;
3457 	int cnt = 0;
3458 
3459 	ata_for_each_dev(dev, link, ALL)
3460 		if (dev->class == ATA_DEV_UNKNOWN)
3461 			cnt++;
3462 	return cnt;
3463 }
3464 
3465 static int ata_eh_skip_recovery(struct ata_link *link)
3466 {
3467 	struct ata_port *ap = link->ap;
3468 	struct ata_eh_context *ehc = &link->eh_context;
3469 	struct ata_device *dev;
3470 
3471 	/* skip disabled links */
3472 	if (link->flags & ATA_LFLAG_DISABLED)
3473 		return 1;
3474 
3475 	/* skip if explicitly requested */
3476 	if (ehc->i.flags & ATA_EHI_NO_RECOVERY)
3477 		return 1;
3478 
3479 	/* thaw frozen port and recover failed devices */
3480 	if ((ap->pflags & ATA_PFLAG_FROZEN) || ata_link_nr_enabled(link))
3481 		return 0;
3482 
3483 	/* reset at least once if reset is requested */
3484 	if ((ehc->i.action & ATA_EH_RESET) &&
3485 	    !(ehc->i.flags & ATA_EHI_DID_RESET))
3486 		return 0;
3487 
3488 	/* skip if class codes for all vacant slots are ATA_DEV_NONE */
3489 	ata_for_each_dev(dev, link, ALL) {
3490 		if (dev->class == ATA_DEV_UNKNOWN &&
3491 		    ehc->classes[dev->devno] != ATA_DEV_NONE)
3492 			return 0;
3493 	}
3494 
3495 	return 1;
3496 }
3497 
3498 static int ata_count_probe_trials_cb(struct ata_ering_entry *ent, void *void_arg)
3499 {
3500 	u64 interval = msecs_to_jiffies(ATA_EH_PROBE_TRIAL_INTERVAL);
3501 	u64 now = get_jiffies_64();
3502 	int *trials = void_arg;
3503 
3504 	if ((ent->eflags & ATA_EFLAG_OLD_ER) ||
3505 	    (ent->timestamp < now - min(now, interval)))
3506 		return -1;
3507 
3508 	(*trials)++;
3509 	return 0;
3510 }
3511 
3512 static int ata_eh_schedule_probe(struct ata_device *dev)
3513 {
3514 	struct ata_eh_context *ehc = &dev->link->eh_context;
3515 	struct ata_link *link = ata_dev_phys_link(dev);
3516 	int trials = 0;
3517 
3518 	if (!(ehc->i.probe_mask & (1 << dev->devno)) ||
3519 	    (ehc->did_probe_mask & (1 << dev->devno)))
3520 		return 0;
3521 
3522 	ata_eh_detach_dev(dev);
3523 	ata_dev_init(dev);
3524 	ehc->did_probe_mask |= (1 << dev->devno);
3525 	ehc->i.action |= ATA_EH_RESET;
3526 	ehc->saved_xfer_mode[dev->devno] = 0;
3527 	ehc->saved_ncq_enabled &= ~(1 << dev->devno);
3528 
3529 	/* the link maybe in a deep sleep, wake it up */
3530 	if (link->lpm_policy > ATA_LPM_MAX_POWER) {
3531 		if (ata_is_host_link(link))
3532 			link->ap->ops->set_lpm(link, ATA_LPM_MAX_POWER,
3533 					       ATA_LPM_EMPTY);
3534 		else
3535 			sata_pmp_set_lpm(link, ATA_LPM_MAX_POWER,
3536 					 ATA_LPM_EMPTY);
3537 	}
3538 
3539 	/* Record and count probe trials on the ering.  The specific
3540 	 * error mask used is irrelevant.  Because a successful device
3541 	 * detection clears the ering, this count accumulates only if
3542 	 * there are consecutive failed probes.
3543 	 *
3544 	 * If the count is equal to or higher than ATA_EH_PROBE_TRIALS
3545 	 * in the last ATA_EH_PROBE_TRIAL_INTERVAL, link speed is
3546 	 * forced to 1.5Gbps.
3547 	 *
3548 	 * This is to work around cases where failed link speed
3549 	 * negotiation results in device misdetection leading to
3550 	 * infinite DEVXCHG or PHRDY CHG events.
3551 	 */
3552 	ata_ering_record(&dev->ering, 0, AC_ERR_OTHER);
3553 	ata_ering_map(&dev->ering, ata_count_probe_trials_cb, &trials);
3554 
3555 	if (trials > ATA_EH_PROBE_TRIALS)
3556 		sata_down_spd_limit(link, 1);
3557 
3558 	return 1;
3559 }
3560 
3561 static int ata_eh_handle_dev_fail(struct ata_device *dev, int err)
3562 {
3563 	struct ata_eh_context *ehc = &dev->link->eh_context;
3564 
3565 	/* -EAGAIN from EH routine indicates retry without prejudice.
3566 	 * The requester is responsible for ensuring forward progress.
3567 	 */
3568 	if (err != -EAGAIN)
3569 		ehc->tries[dev->devno]--;
3570 
3571 	switch (err) {
3572 	case -ENODEV:
3573 		/* device missing or wrong IDENTIFY data, schedule probing */
3574 		ehc->i.probe_mask |= (1 << dev->devno);
3575 	case -EINVAL:
3576 		/* give it just one more chance */
3577 		ehc->tries[dev->devno] = min(ehc->tries[dev->devno], 1);
3578 	case -EIO:
3579 		if (ehc->tries[dev->devno] == 1) {
3580 			/* This is the last chance, better to slow
3581 			 * down than lose it.
3582 			 */
3583 			sata_down_spd_limit(ata_dev_phys_link(dev), 0);
3584 			if (dev->pio_mode > XFER_PIO_0)
3585 				ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
3586 		}
3587 	}
3588 
3589 	if (ata_dev_enabled(dev) && !ehc->tries[dev->devno]) {
3590 		/* disable device if it has used up all its chances */
3591 		ata_dev_disable(dev);
3592 
3593 		/* detach if offline */
3594 		if (ata_phys_link_offline(ata_dev_phys_link(dev)))
3595 			ata_eh_detach_dev(dev);
3596 
3597 		/* schedule probe if necessary */
3598 		if (ata_eh_schedule_probe(dev)) {
3599 			ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
3600 			memset(ehc->cmd_timeout_idx[dev->devno], 0,
3601 			       sizeof(ehc->cmd_timeout_idx[dev->devno]));
3602 		}
3603 
3604 		return 1;
3605 	} else {
3606 		ehc->i.action |= ATA_EH_RESET;
3607 		return 0;
3608 	}
3609 }
3610 
3611 /**
3612  *	ata_eh_recover - recover host port after error
3613  *	@ap: host port to recover
3614  *	@prereset: prereset method (can be NULL)
3615  *	@softreset: softreset method (can be NULL)
3616  *	@hardreset: hardreset method (can be NULL)
3617  *	@postreset: postreset method (can be NULL)
3618  *	@r_failed_link: out parameter for failed link
3619  *
3620  *	This is the alpha and omega, eum and yang, heart and soul of
3621  *	libata exception handling.  On entry, actions required to
3622  *	recover each link and hotplug requests are recorded in the
3623  *	link's eh_context.  This function executes all the operations
3624  *	with appropriate retrials and fallbacks to resurrect failed
3625  *	devices, detach goners and greet newcomers.
3626  *
3627  *	LOCKING:
3628  *	Kernel thread context (may sleep).
3629  *
3630  *	RETURNS:
3631  *	0 on success, -errno on failure.
3632  */
3633 int ata_eh_recover(struct ata_port *ap, ata_prereset_fn_t prereset,
3634 		   ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
3635 		   ata_postreset_fn_t postreset,
3636 		   struct ata_link **r_failed_link)
3637 {
3638 	struct ata_link *link;
3639 	struct ata_device *dev;
3640 	int rc, nr_fails;
3641 	unsigned long flags, deadline;
3642 
3643 	DPRINTK("ENTER\n");
3644 
3645 	/* prep for recovery */
3646 	ata_for_each_link(link, ap, EDGE) {
3647 		struct ata_eh_context *ehc = &link->eh_context;
3648 
3649 		/* re-enable link? */
3650 		if (ehc->i.action & ATA_EH_ENABLE_LINK) {
3651 			ata_eh_about_to_do(link, NULL, ATA_EH_ENABLE_LINK);
3652 			spin_lock_irqsave(ap->lock, flags);
3653 			link->flags &= ~ATA_LFLAG_DISABLED;
3654 			spin_unlock_irqrestore(ap->lock, flags);
3655 			ata_eh_done(link, NULL, ATA_EH_ENABLE_LINK);
3656 		}
3657 
3658 		ata_for_each_dev(dev, link, ALL) {
3659 			if (link->flags & ATA_LFLAG_NO_RETRY)
3660 				ehc->tries[dev->devno] = 1;
3661 			else
3662 				ehc->tries[dev->devno] = ATA_EH_DEV_TRIES;
3663 
3664 			/* collect port action mask recorded in dev actions */
3665 			ehc->i.action |= ehc->i.dev_action[dev->devno] &
3666 					 ~ATA_EH_PERDEV_MASK;
3667 			ehc->i.dev_action[dev->devno] &= ATA_EH_PERDEV_MASK;
3668 
3669 			/* process hotplug request */
3670 			if (dev->flags & ATA_DFLAG_DETACH)
3671 				ata_eh_detach_dev(dev);
3672 
3673 			/* schedule probe if necessary */
3674 			if (!ata_dev_enabled(dev))
3675 				ata_eh_schedule_probe(dev);
3676 		}
3677 	}
3678 
3679  retry:
3680 	rc = 0;
3681 
3682 	/* if UNLOADING, finish immediately */
3683 	if (ap->pflags & ATA_PFLAG_UNLOADING)
3684 		goto out;
3685 
3686 	/* prep for EH */
3687 	ata_for_each_link(link, ap, EDGE) {
3688 		struct ata_eh_context *ehc = &link->eh_context;
3689 
3690 		/* skip EH if possible. */
3691 		if (ata_eh_skip_recovery(link))
3692 			ehc->i.action = 0;
3693 
3694 		ata_for_each_dev(dev, link, ALL)
3695 			ehc->classes[dev->devno] = ATA_DEV_UNKNOWN;
3696 	}
3697 
3698 	/* reset */
3699 	ata_for_each_link(link, ap, EDGE) {
3700 		struct ata_eh_context *ehc = &link->eh_context;
3701 
3702 		if (!(ehc->i.action & ATA_EH_RESET))
3703 			continue;
3704 
3705 		rc = ata_eh_reset(link, ata_link_nr_vacant(link),
3706 				  prereset, softreset, hardreset, postreset);
3707 		if (rc) {
3708 			ata_link_err(link, "reset failed, giving up\n");
3709 			goto out;
3710 		}
3711 	}
3712 
3713 	do {
3714 		unsigned long now;
3715 
3716 		/*
3717 		 * clears ATA_EH_PARK in eh_info and resets
3718 		 * ap->park_req_pending
3719 		 */
3720 		ata_eh_pull_park_action(ap);
3721 
3722 		deadline = jiffies;
3723 		ata_for_each_link(link, ap, EDGE) {
3724 			ata_for_each_dev(dev, link, ALL) {
3725 				struct ata_eh_context *ehc = &link->eh_context;
3726 				unsigned long tmp;
3727 
3728 				if (dev->class != ATA_DEV_ATA)
3729 					continue;
3730 				if (!(ehc->i.dev_action[dev->devno] &
3731 				      ATA_EH_PARK))
3732 					continue;
3733 				tmp = dev->unpark_deadline;
3734 				if (time_before(deadline, tmp))
3735 					deadline = tmp;
3736 				else if (time_before_eq(tmp, jiffies))
3737 					continue;
3738 				if (ehc->unloaded_mask & (1 << dev->devno))
3739 					continue;
3740 
3741 				ata_eh_park_issue_cmd(dev, 1);
3742 			}
3743 		}
3744 
3745 		now = jiffies;
3746 		if (time_before_eq(deadline, now))
3747 			break;
3748 
3749 		ata_eh_release(ap);
3750 		deadline = wait_for_completion_timeout(&ap->park_req_pending,
3751 						       deadline - now);
3752 		ata_eh_acquire(ap);
3753 	} while (deadline);
3754 	ata_for_each_link(link, ap, EDGE) {
3755 		ata_for_each_dev(dev, link, ALL) {
3756 			if (!(link->eh_context.unloaded_mask &
3757 			      (1 << dev->devno)))
3758 				continue;
3759 
3760 			ata_eh_park_issue_cmd(dev, 0);
3761 			ata_eh_done(link, dev, ATA_EH_PARK);
3762 		}
3763 	}
3764 
3765 	/* the rest */
3766 	nr_fails = 0;
3767 	ata_for_each_link(link, ap, PMP_FIRST) {
3768 		struct ata_eh_context *ehc = &link->eh_context;
3769 
3770 		if (sata_pmp_attached(ap) && ata_is_host_link(link))
3771 			goto config_lpm;
3772 
3773 		/* revalidate existing devices and attach new ones */
3774 		rc = ata_eh_revalidate_and_attach(link, &dev);
3775 		if (rc)
3776 			goto rest_fail;
3777 
3778 		/* if PMP got attached, return, pmp EH will take care of it */
3779 		if (link->device->class == ATA_DEV_PMP) {
3780 			ehc->i.action = 0;
3781 			return 0;
3782 		}
3783 
3784 		/* configure transfer mode if necessary */
3785 		if (ehc->i.flags & ATA_EHI_SETMODE) {
3786 			rc = ata_set_mode(link, &dev);
3787 			if (rc)
3788 				goto rest_fail;
3789 			ehc->i.flags &= ~ATA_EHI_SETMODE;
3790 		}
3791 
3792 		/* If reset has been issued, clear UA to avoid
3793 		 * disrupting the current users of the device.
3794 		 */
3795 		if (ehc->i.flags & ATA_EHI_DID_RESET) {
3796 			ata_for_each_dev(dev, link, ALL) {
3797 				if (dev->class != ATA_DEV_ATAPI)
3798 					continue;
3799 				rc = atapi_eh_clear_ua(dev);
3800 				if (rc)
3801 					goto rest_fail;
3802 			}
3803 		}
3804 
3805 		/* retry flush if necessary */
3806 		ata_for_each_dev(dev, link, ALL) {
3807 			if (dev->class != ATA_DEV_ATA)
3808 				continue;
3809 			rc = ata_eh_maybe_retry_flush(dev);
3810 			if (rc)
3811 				goto rest_fail;
3812 		}
3813 
3814 	config_lpm:
3815 		/* configure link power saving */
3816 		if (link->lpm_policy != ap->target_lpm_policy) {
3817 			rc = ata_eh_set_lpm(link, ap->target_lpm_policy, &dev);
3818 			if (rc)
3819 				goto rest_fail;
3820 		}
3821 
3822 		/* this link is okay now */
3823 		ehc->i.flags = 0;
3824 		continue;
3825 
3826 	rest_fail:
3827 		nr_fails++;
3828 		if (dev)
3829 			ata_eh_handle_dev_fail(dev, rc);
3830 
3831 		if (ap->pflags & ATA_PFLAG_FROZEN) {
3832 			/* PMP reset requires working host port.
3833 			 * Can't retry if it's frozen.
3834 			 */
3835 			if (sata_pmp_attached(ap))
3836 				goto out;
3837 			break;
3838 		}
3839 	}
3840 
3841 	if (nr_fails)
3842 		goto retry;
3843 
3844  out:
3845 	if (rc && r_failed_link)
3846 		*r_failed_link = link;
3847 
3848 	DPRINTK("EXIT, rc=%d\n", rc);
3849 	return rc;
3850 }
3851 
3852 /**
3853  *	ata_eh_finish - finish up EH
3854  *	@ap: host port to finish EH for
3855  *
3856  *	Recovery is complete.  Clean up EH states and retry or finish
3857  *	failed qcs.
3858  *
3859  *	LOCKING:
3860  *	None.
3861  */
3862 void ata_eh_finish(struct ata_port *ap)
3863 {
3864 	int tag;
3865 
3866 	/* retry or finish qcs */
3867 	for (tag = 0; tag < ATA_MAX_QUEUE; tag++) {
3868 		struct ata_queued_cmd *qc = __ata_qc_from_tag(ap, tag);
3869 
3870 		if (!(qc->flags & ATA_QCFLAG_FAILED))
3871 			continue;
3872 
3873 		if (qc->err_mask) {
3874 			/* FIXME: Once EH migration is complete,
3875 			 * generate sense data in this function,
3876 			 * considering both err_mask and tf.
3877 			 */
3878 			if (qc->flags & ATA_QCFLAG_RETRY)
3879 				ata_eh_qc_retry(qc);
3880 			else
3881 				ata_eh_qc_complete(qc);
3882 		} else {
3883 			if (qc->flags & ATA_QCFLAG_SENSE_VALID) {
3884 				ata_eh_qc_complete(qc);
3885 			} else {
3886 				/* feed zero TF to sense generation */
3887 				memset(&qc->result_tf, 0, sizeof(qc->result_tf));
3888 				ata_eh_qc_retry(qc);
3889 			}
3890 		}
3891 	}
3892 
3893 	/* make sure nr_active_links is zero after EH */
3894 	WARN_ON(ap->nr_active_links);
3895 	ap->nr_active_links = 0;
3896 }
3897 
3898 /**
3899  *	ata_do_eh - do standard error handling
3900  *	@ap: host port to handle error for
3901  *
3902  *	@prereset: prereset method (can be NULL)
3903  *	@softreset: softreset method (can be NULL)
3904  *	@hardreset: hardreset method (can be NULL)
3905  *	@postreset: postreset method (can be NULL)
3906  *
3907  *	Perform standard error handling sequence.
3908  *
3909  *	LOCKING:
3910  *	Kernel thread context (may sleep).
3911  */
3912 void ata_do_eh(struct ata_port *ap, ata_prereset_fn_t prereset,
3913 	       ata_reset_fn_t softreset, ata_reset_fn_t hardreset,
3914 	       ata_postreset_fn_t postreset)
3915 {
3916 	struct ata_device *dev;
3917 	int rc;
3918 
3919 	ata_eh_autopsy(ap);
3920 	ata_eh_report(ap);
3921 
3922 	rc = ata_eh_recover(ap, prereset, softreset, hardreset, postreset,
3923 			    NULL);
3924 	if (rc) {
3925 		ata_for_each_dev(dev, &ap->link, ALL)
3926 			ata_dev_disable(dev);
3927 	}
3928 
3929 	ata_eh_finish(ap);
3930 }
3931 
3932 /**
3933  *	ata_std_error_handler - standard error handler
3934  *	@ap: host port to handle error for
3935  *
3936  *	Standard error handler
3937  *
3938  *	LOCKING:
3939  *	Kernel thread context (may sleep).
3940  */
3941 void ata_std_error_handler(struct ata_port *ap)
3942 {
3943 	struct ata_port_operations *ops = ap->ops;
3944 	ata_reset_fn_t hardreset = ops->hardreset;
3945 
3946 	/* ignore built-in hardreset if SCR access is not available */
3947 	if (hardreset == sata_std_hardreset && !sata_scr_valid(&ap->link))
3948 		hardreset = NULL;
3949 
3950 	ata_do_eh(ap, ops->prereset, ops->softreset, hardreset, ops->postreset);
3951 }
3952 
3953 #ifdef CONFIG_PM
3954 /**
3955  *	ata_eh_handle_port_suspend - perform port suspend operation
3956  *	@ap: port to suspend
3957  *
3958  *	Suspend @ap.
3959  *
3960  *	LOCKING:
3961  *	Kernel thread context (may sleep).
3962  */
3963 static void ata_eh_handle_port_suspend(struct ata_port *ap)
3964 {
3965 	unsigned long flags;
3966 	int rc = 0;
3967 
3968 	/* are we suspending? */
3969 	spin_lock_irqsave(ap->lock, flags);
3970 	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
3971 	    ap->pm_mesg.event == PM_EVENT_ON) {
3972 		spin_unlock_irqrestore(ap->lock, flags);
3973 		return;
3974 	}
3975 	spin_unlock_irqrestore(ap->lock, flags);
3976 
3977 	WARN_ON(ap->pflags & ATA_PFLAG_SUSPENDED);
3978 
3979 	/* tell ACPI we're suspending */
3980 	rc = ata_acpi_on_suspend(ap);
3981 	if (rc)
3982 		goto out;
3983 
3984 	/* suspend */
3985 	ata_eh_freeze_port(ap);
3986 
3987 	if (ap->ops->port_suspend)
3988 		rc = ap->ops->port_suspend(ap, ap->pm_mesg);
3989 
3990 	ata_acpi_set_state(ap, PMSG_SUSPEND);
3991  out:
3992 	/* report result */
3993 	spin_lock_irqsave(ap->lock, flags);
3994 
3995 	ap->pflags &= ~ATA_PFLAG_PM_PENDING;
3996 	if (rc == 0)
3997 		ap->pflags |= ATA_PFLAG_SUSPENDED;
3998 	else if (ap->pflags & ATA_PFLAG_FROZEN)
3999 		ata_port_schedule_eh(ap);
4000 
4001 	if (ap->pm_result) {
4002 		*ap->pm_result = rc;
4003 		ap->pm_result = NULL;
4004 	}
4005 
4006 	spin_unlock_irqrestore(ap->lock, flags);
4007 
4008 	return;
4009 }
4010 
4011 /**
4012  *	ata_eh_handle_port_resume - perform port resume operation
4013  *	@ap: port to resume
4014  *
4015  *	Resume @ap.
4016  *
4017  *	LOCKING:
4018  *	Kernel thread context (may sleep).
4019  */
4020 static void ata_eh_handle_port_resume(struct ata_port *ap)
4021 {
4022 	struct ata_link *link;
4023 	struct ata_device *dev;
4024 	unsigned long flags;
4025 	int rc = 0;
4026 
4027 	/* are we resuming? */
4028 	spin_lock_irqsave(ap->lock, flags);
4029 	if (!(ap->pflags & ATA_PFLAG_PM_PENDING) ||
4030 	    ap->pm_mesg.event != PM_EVENT_ON) {
4031 		spin_unlock_irqrestore(ap->lock, flags);
4032 		return;
4033 	}
4034 	spin_unlock_irqrestore(ap->lock, flags);
4035 
4036 	WARN_ON(!(ap->pflags & ATA_PFLAG_SUSPENDED));
4037 
4038 	/*
4039 	 * Error timestamps are in jiffies which doesn't run while
4040 	 * suspended and PHY events during resume isn't too uncommon.
4041 	 * When the two are combined, it can lead to unnecessary speed
4042 	 * downs if the machine is suspended and resumed repeatedly.
4043 	 * Clear error history.
4044 	 */
4045 	ata_for_each_link(link, ap, HOST_FIRST)
4046 		ata_for_each_dev(dev, link, ALL)
4047 			ata_ering_clear(&dev->ering);
4048 
4049 	ata_acpi_set_state(ap, PMSG_ON);
4050 
4051 	if (ap->ops->port_resume)
4052 		rc = ap->ops->port_resume(ap);
4053 
4054 	/* tell ACPI that we're resuming */
4055 	ata_acpi_on_resume(ap);
4056 
4057 	/* report result */
4058 	spin_lock_irqsave(ap->lock, flags);
4059 	ap->pflags &= ~(ATA_PFLAG_PM_PENDING | ATA_PFLAG_SUSPENDED);
4060 	if (ap->pm_result) {
4061 		*ap->pm_result = rc;
4062 		ap->pm_result = NULL;
4063 	}
4064 	spin_unlock_irqrestore(ap->lock, flags);
4065 }
4066 #endif /* CONFIG_PM */
4067