xref: /openbmc/linux/drivers/usb/storage/uas.c (revision aeb64ff3)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * USB Attached SCSI
4  * Note that this is not the same as the USB Mass Storage driver
5  *
6  * Copyright Hans de Goede <hdegoede@redhat.com> for Red Hat, Inc. 2013 - 2016
7  * Copyright Matthew Wilcox for Intel Corp, 2010
8  * Copyright Sarah Sharp for Intel Corp, 2010
9  */
10 
11 #include <linux/blkdev.h>
12 #include <linux/slab.h>
13 #include <linux/types.h>
14 #include <linux/module.h>
15 #include <linux/usb.h>
16 #include <linux/usb_usual.h>
17 #include <linux/usb/hcd.h>
18 #include <linux/usb/storage.h>
19 #include <linux/usb/uas.h>
20 
21 #include <scsi/scsi.h>
22 #include <scsi/scsi_eh.h>
23 #include <scsi/scsi_dbg.h>
24 #include <scsi/scsi_cmnd.h>
25 #include <scsi/scsi_device.h>
26 #include <scsi/scsi_host.h>
27 #include <scsi/scsi_tcq.h>
28 
29 #include "uas-detect.h"
30 #include "scsiglue.h"
31 
32 #define MAX_CMNDS 256
33 
34 struct uas_dev_info {
35 	struct usb_interface *intf;
36 	struct usb_device *udev;
37 	struct usb_anchor cmd_urbs;
38 	struct usb_anchor sense_urbs;
39 	struct usb_anchor data_urbs;
40 	unsigned long flags;
41 	int qdepth, resetting;
42 	unsigned cmd_pipe, status_pipe, data_in_pipe, data_out_pipe;
43 	unsigned use_streams:1;
44 	unsigned shutdown:1;
45 	struct scsi_cmnd *cmnd[MAX_CMNDS];
46 	spinlock_t lock;
47 	struct work_struct work;
48 };
49 
50 enum {
51 	SUBMIT_STATUS_URB	= BIT(1),
52 	ALLOC_DATA_IN_URB	= BIT(2),
53 	SUBMIT_DATA_IN_URB	= BIT(3),
54 	ALLOC_DATA_OUT_URB	= BIT(4),
55 	SUBMIT_DATA_OUT_URB	= BIT(5),
56 	ALLOC_CMD_URB		= BIT(6),
57 	SUBMIT_CMD_URB		= BIT(7),
58 	COMMAND_INFLIGHT        = BIT(8),
59 	DATA_IN_URB_INFLIGHT    = BIT(9),
60 	DATA_OUT_URB_INFLIGHT   = BIT(10),
61 	COMMAND_ABORTED         = BIT(11),
62 	IS_IN_WORK_LIST         = BIT(12),
63 };
64 
65 /* Overrides scsi_pointer */
66 struct uas_cmd_info {
67 	unsigned int state;
68 	unsigned int uas_tag;
69 	struct urb *cmd_urb;
70 	struct urb *data_in_urb;
71 	struct urb *data_out_urb;
72 };
73 
74 /* I hate forward declarations, but I actually have a loop */
75 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
76 				struct uas_dev_info *devinfo);
77 static void uas_do_work(struct work_struct *work);
78 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller);
79 static void uas_free_streams(struct uas_dev_info *devinfo);
80 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
81 				int status);
82 
83 static void uas_do_work(struct work_struct *work)
84 {
85 	struct uas_dev_info *devinfo =
86 		container_of(work, struct uas_dev_info, work);
87 	struct uas_cmd_info *cmdinfo;
88 	struct scsi_cmnd *cmnd;
89 	unsigned long flags;
90 	int i, err;
91 
92 	spin_lock_irqsave(&devinfo->lock, flags);
93 
94 	if (devinfo->resetting)
95 		goto out;
96 
97 	for (i = 0; i < devinfo->qdepth; i++) {
98 		if (!devinfo->cmnd[i])
99 			continue;
100 
101 		cmnd = devinfo->cmnd[i];
102 		cmdinfo = (void *)&cmnd->SCp;
103 
104 		if (!(cmdinfo->state & IS_IN_WORK_LIST))
105 			continue;
106 
107 		err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
108 		if (!err)
109 			cmdinfo->state &= ~IS_IN_WORK_LIST;
110 		else
111 			schedule_work(&devinfo->work);
112 	}
113 out:
114 	spin_unlock_irqrestore(&devinfo->lock, flags);
115 }
116 
117 static void uas_add_work(struct uas_cmd_info *cmdinfo)
118 {
119 	struct scsi_pointer *scp = (void *)cmdinfo;
120 	struct scsi_cmnd *cmnd = container_of(scp, struct scsi_cmnd, SCp);
121 	struct uas_dev_info *devinfo = cmnd->device->hostdata;
122 
123 	lockdep_assert_held(&devinfo->lock);
124 	cmdinfo->state |= IS_IN_WORK_LIST;
125 	schedule_work(&devinfo->work);
126 }
127 
128 static void uas_zap_pending(struct uas_dev_info *devinfo, int result)
129 {
130 	struct uas_cmd_info *cmdinfo;
131 	struct scsi_cmnd *cmnd;
132 	unsigned long flags;
133 	int i, err;
134 
135 	spin_lock_irqsave(&devinfo->lock, flags);
136 	for (i = 0; i < devinfo->qdepth; i++) {
137 		if (!devinfo->cmnd[i])
138 			continue;
139 
140 		cmnd = devinfo->cmnd[i];
141 		cmdinfo = (void *)&cmnd->SCp;
142 		uas_log_cmd_state(cmnd, __func__, 0);
143 		/* Sense urbs were killed, clear COMMAND_INFLIGHT manually */
144 		cmdinfo->state &= ~COMMAND_INFLIGHT;
145 		cmnd->result = result << 16;
146 		err = uas_try_complete(cmnd, __func__);
147 		WARN_ON(err != 0);
148 	}
149 	spin_unlock_irqrestore(&devinfo->lock, flags);
150 }
151 
152 static void uas_sense(struct urb *urb, struct scsi_cmnd *cmnd)
153 {
154 	struct sense_iu *sense_iu = urb->transfer_buffer;
155 	struct scsi_device *sdev = cmnd->device;
156 
157 	if (urb->actual_length > 16) {
158 		unsigned len = be16_to_cpup(&sense_iu->len);
159 		if (len + 16 != urb->actual_length) {
160 			int newlen = min(len + 16, urb->actual_length) - 16;
161 			if (newlen < 0)
162 				newlen = 0;
163 			sdev_printk(KERN_INFO, sdev, "%s: urb length %d "
164 				"disagrees with IU sense data length %d, "
165 				"using %d bytes of sense data\n", __func__,
166 					urb->actual_length, len, newlen);
167 			len = newlen;
168 		}
169 		memcpy(cmnd->sense_buffer, sense_iu->sense, len);
170 	}
171 
172 	cmnd->result = sense_iu->status;
173 }
174 
175 static void uas_log_cmd_state(struct scsi_cmnd *cmnd, const char *prefix,
176 			      int status)
177 {
178 	struct uas_cmd_info *ci = (void *)&cmnd->SCp;
179 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
180 
181 	scmd_printk(KERN_INFO, cmnd,
182 		    "%s %d uas-tag %d inflight:%s%s%s%s%s%s%s%s%s%s%s%s ",
183 		    prefix, status, cmdinfo->uas_tag,
184 		    (ci->state & SUBMIT_STATUS_URB)     ? " s-st"  : "",
185 		    (ci->state & ALLOC_DATA_IN_URB)     ? " a-in"  : "",
186 		    (ci->state & SUBMIT_DATA_IN_URB)    ? " s-in"  : "",
187 		    (ci->state & ALLOC_DATA_OUT_URB)    ? " a-out" : "",
188 		    (ci->state & SUBMIT_DATA_OUT_URB)   ? " s-out" : "",
189 		    (ci->state & ALLOC_CMD_URB)         ? " a-cmd" : "",
190 		    (ci->state & SUBMIT_CMD_URB)        ? " s-cmd" : "",
191 		    (ci->state & COMMAND_INFLIGHT)      ? " CMD"   : "",
192 		    (ci->state & DATA_IN_URB_INFLIGHT)  ? " IN"    : "",
193 		    (ci->state & DATA_OUT_URB_INFLIGHT) ? " OUT"   : "",
194 		    (ci->state & COMMAND_ABORTED)       ? " abort" : "",
195 		    (ci->state & IS_IN_WORK_LIST)       ? " work"  : "");
196 	scsi_print_command(cmnd);
197 }
198 
199 static void uas_free_unsubmitted_urbs(struct scsi_cmnd *cmnd)
200 {
201 	struct uas_cmd_info *cmdinfo;
202 
203 	if (!cmnd)
204 		return;
205 
206 	cmdinfo = (void *)&cmnd->SCp;
207 
208 	if (cmdinfo->state & SUBMIT_CMD_URB)
209 		usb_free_urb(cmdinfo->cmd_urb);
210 
211 	/* data urbs may have never gotten their submit flag set */
212 	if (!(cmdinfo->state & DATA_IN_URB_INFLIGHT))
213 		usb_free_urb(cmdinfo->data_in_urb);
214 	if (!(cmdinfo->state & DATA_OUT_URB_INFLIGHT))
215 		usb_free_urb(cmdinfo->data_out_urb);
216 }
217 
218 static int uas_try_complete(struct scsi_cmnd *cmnd, const char *caller)
219 {
220 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
221 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
222 
223 	lockdep_assert_held(&devinfo->lock);
224 	if (cmdinfo->state & (COMMAND_INFLIGHT |
225 			      DATA_IN_URB_INFLIGHT |
226 			      DATA_OUT_URB_INFLIGHT |
227 			      COMMAND_ABORTED))
228 		return -EBUSY;
229 	devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
230 	uas_free_unsubmitted_urbs(cmnd);
231 	cmnd->scsi_done(cmnd);
232 	return 0;
233 }
234 
235 static void uas_xfer_data(struct urb *urb, struct scsi_cmnd *cmnd,
236 			  unsigned direction)
237 {
238 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
239 	int err;
240 
241 	cmdinfo->state |= direction | SUBMIT_STATUS_URB;
242 	err = uas_submit_urbs(cmnd, cmnd->device->hostdata);
243 	if (err) {
244 		uas_add_work(cmdinfo);
245 	}
246 }
247 
248 static bool uas_evaluate_response_iu(struct response_iu *riu, struct scsi_cmnd *cmnd)
249 {
250 	u8 response_code = riu->response_code;
251 
252 	switch (response_code) {
253 	case RC_INCORRECT_LUN:
254 		cmnd->result = DID_BAD_TARGET << 16;
255 		break;
256 	case RC_TMF_SUCCEEDED:
257 		cmnd->result = DID_OK << 16;
258 		break;
259 	case RC_TMF_NOT_SUPPORTED:
260 		cmnd->result = DID_TARGET_FAILURE << 16;
261 		break;
262 	default:
263 		uas_log_cmd_state(cmnd, "response iu", response_code);
264 		cmnd->result = DID_ERROR << 16;
265 		break;
266 	}
267 
268 	return response_code == RC_TMF_SUCCEEDED;
269 }
270 
271 static void uas_stat_cmplt(struct urb *urb)
272 {
273 	struct iu *iu = urb->transfer_buffer;
274 	struct Scsi_Host *shost = urb->context;
275 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
276 	struct urb *data_in_urb = NULL;
277 	struct urb *data_out_urb = NULL;
278 	struct scsi_cmnd *cmnd;
279 	struct uas_cmd_info *cmdinfo;
280 	unsigned long flags;
281 	unsigned int idx;
282 	int status = urb->status;
283 	bool success;
284 
285 	spin_lock_irqsave(&devinfo->lock, flags);
286 
287 	if (devinfo->resetting)
288 		goto out;
289 
290 	if (status) {
291 		if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
292 			dev_err(&urb->dev->dev, "stat urb: status %d\n", status);
293 		goto out;
294 	}
295 
296 	idx = be16_to_cpup(&iu->tag) - 1;
297 	if (idx >= MAX_CMNDS || !devinfo->cmnd[idx]) {
298 		dev_err(&urb->dev->dev,
299 			"stat urb: no pending cmd for uas-tag %d\n", idx + 1);
300 		goto out;
301 	}
302 
303 	cmnd = devinfo->cmnd[idx];
304 	cmdinfo = (void *)&cmnd->SCp;
305 
306 	if (!(cmdinfo->state & COMMAND_INFLIGHT)) {
307 		uas_log_cmd_state(cmnd, "unexpected status cmplt", 0);
308 		goto out;
309 	}
310 
311 	switch (iu->iu_id) {
312 	case IU_ID_STATUS:
313 		uas_sense(urb, cmnd);
314 		if (cmnd->result != 0) {
315 			/* cancel data transfers on error */
316 			data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
317 			data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
318 		}
319 		cmdinfo->state &= ~COMMAND_INFLIGHT;
320 		uas_try_complete(cmnd, __func__);
321 		break;
322 	case IU_ID_READ_READY:
323 		if (!cmdinfo->data_in_urb ||
324 				(cmdinfo->state & DATA_IN_URB_INFLIGHT)) {
325 			uas_log_cmd_state(cmnd, "unexpected read rdy", 0);
326 			break;
327 		}
328 		uas_xfer_data(urb, cmnd, SUBMIT_DATA_IN_URB);
329 		break;
330 	case IU_ID_WRITE_READY:
331 		if (!cmdinfo->data_out_urb ||
332 				(cmdinfo->state & DATA_OUT_URB_INFLIGHT)) {
333 			uas_log_cmd_state(cmnd, "unexpected write rdy", 0);
334 			break;
335 		}
336 		uas_xfer_data(urb, cmnd, SUBMIT_DATA_OUT_URB);
337 		break;
338 	case IU_ID_RESPONSE:
339 		cmdinfo->state &= ~COMMAND_INFLIGHT;
340 		success = uas_evaluate_response_iu((struct response_iu *)iu, cmnd);
341 		if (!success) {
342 			/* Error, cancel data transfers */
343 			data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
344 			data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
345 		}
346 		uas_try_complete(cmnd, __func__);
347 		break;
348 	default:
349 		uas_log_cmd_state(cmnd, "bogus IU", iu->iu_id);
350 	}
351 out:
352 	usb_free_urb(urb);
353 	spin_unlock_irqrestore(&devinfo->lock, flags);
354 
355 	/* Unlinking of data urbs must be done without holding the lock */
356 	if (data_in_urb) {
357 		usb_unlink_urb(data_in_urb);
358 		usb_put_urb(data_in_urb);
359 	}
360 	if (data_out_urb) {
361 		usb_unlink_urb(data_out_urb);
362 		usb_put_urb(data_out_urb);
363 	}
364 }
365 
366 static void uas_data_cmplt(struct urb *urb)
367 {
368 	struct scsi_cmnd *cmnd = urb->context;
369 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
370 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
371 	struct scsi_data_buffer *sdb = &cmnd->sdb;
372 	unsigned long flags;
373 	int status = urb->status;
374 
375 	spin_lock_irqsave(&devinfo->lock, flags);
376 
377 	if (cmdinfo->data_in_urb == urb) {
378 		cmdinfo->state &= ~DATA_IN_URB_INFLIGHT;
379 		cmdinfo->data_in_urb = NULL;
380 	} else if (cmdinfo->data_out_urb == urb) {
381 		cmdinfo->state &= ~DATA_OUT_URB_INFLIGHT;
382 		cmdinfo->data_out_urb = NULL;
383 	}
384 
385 	if (devinfo->resetting)
386 		goto out;
387 
388 	/* Data urbs should not complete before the cmd urb is submitted */
389 	if (cmdinfo->state & SUBMIT_CMD_URB) {
390 		uas_log_cmd_state(cmnd, "unexpected data cmplt", 0);
391 		goto out;
392 	}
393 
394 	if (status) {
395 		if (status != -ENOENT && status != -ECONNRESET && status != -ESHUTDOWN)
396 			uas_log_cmd_state(cmnd, "data cmplt err", status);
397 		/* error: no data transfered */
398 		scsi_set_resid(cmnd, sdb->length);
399 	} else {
400 		scsi_set_resid(cmnd, sdb->length - urb->actual_length);
401 	}
402 	uas_try_complete(cmnd, __func__);
403 out:
404 	usb_free_urb(urb);
405 	spin_unlock_irqrestore(&devinfo->lock, flags);
406 }
407 
408 static void uas_cmd_cmplt(struct urb *urb)
409 {
410 	if (urb->status)
411 		dev_err(&urb->dev->dev, "cmd cmplt err %d\n", urb->status);
412 
413 	usb_free_urb(urb);
414 }
415 
416 static struct urb *uas_alloc_data_urb(struct uas_dev_info *devinfo, gfp_t gfp,
417 				      struct scsi_cmnd *cmnd,
418 				      enum dma_data_direction dir)
419 {
420 	struct usb_device *udev = devinfo->udev;
421 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
422 	struct urb *urb = usb_alloc_urb(0, gfp);
423 	struct scsi_data_buffer *sdb = &cmnd->sdb;
424 	unsigned int pipe = (dir == DMA_FROM_DEVICE)
425 		? devinfo->data_in_pipe : devinfo->data_out_pipe;
426 
427 	if (!urb)
428 		goto out;
429 	usb_fill_bulk_urb(urb, udev, pipe, NULL, sdb->length,
430 			  uas_data_cmplt, cmnd);
431 	if (devinfo->use_streams)
432 		urb->stream_id = cmdinfo->uas_tag;
433 	urb->num_sgs = udev->bus->sg_tablesize ? sdb->table.nents : 0;
434 	urb->sg = sdb->table.sgl;
435  out:
436 	return urb;
437 }
438 
439 static struct urb *uas_alloc_sense_urb(struct uas_dev_info *devinfo, gfp_t gfp,
440 				       struct scsi_cmnd *cmnd)
441 {
442 	struct usb_device *udev = devinfo->udev;
443 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
444 	struct urb *urb = usb_alloc_urb(0, gfp);
445 	struct sense_iu *iu;
446 
447 	if (!urb)
448 		goto out;
449 
450 	iu = kzalloc(sizeof(*iu), gfp);
451 	if (!iu)
452 		goto free;
453 
454 	usb_fill_bulk_urb(urb, udev, devinfo->status_pipe, iu, sizeof(*iu),
455 			  uas_stat_cmplt, cmnd->device->host);
456 	if (devinfo->use_streams)
457 		urb->stream_id = cmdinfo->uas_tag;
458 	urb->transfer_flags |= URB_FREE_BUFFER;
459  out:
460 	return urb;
461  free:
462 	usb_free_urb(urb);
463 	return NULL;
464 }
465 
466 static struct urb *uas_alloc_cmd_urb(struct uas_dev_info *devinfo, gfp_t gfp,
467 					struct scsi_cmnd *cmnd)
468 {
469 	struct usb_device *udev = devinfo->udev;
470 	struct scsi_device *sdev = cmnd->device;
471 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
472 	struct urb *urb = usb_alloc_urb(0, gfp);
473 	struct command_iu *iu;
474 	int len;
475 
476 	if (!urb)
477 		goto out;
478 
479 	len = cmnd->cmd_len - 16;
480 	if (len < 0)
481 		len = 0;
482 	len = ALIGN(len, 4);
483 	iu = kzalloc(sizeof(*iu) + len, gfp);
484 	if (!iu)
485 		goto free;
486 
487 	iu->iu_id = IU_ID_COMMAND;
488 	iu->tag = cpu_to_be16(cmdinfo->uas_tag);
489 	iu->prio_attr = UAS_SIMPLE_TAG;
490 	iu->len = len;
491 	int_to_scsilun(sdev->lun, &iu->lun);
492 	memcpy(iu->cdb, cmnd->cmnd, cmnd->cmd_len);
493 
494 	usb_fill_bulk_urb(urb, udev, devinfo->cmd_pipe, iu, sizeof(*iu) + len,
495 							uas_cmd_cmplt, NULL);
496 	urb->transfer_flags |= URB_FREE_BUFFER;
497  out:
498 	return urb;
499  free:
500 	usb_free_urb(urb);
501 	return NULL;
502 }
503 
504 /*
505  * Why should I request the Status IU before sending the Command IU?  Spec
506  * says to, but also says the device may receive them in any order.  Seems
507  * daft to me.
508  */
509 
510 static struct urb *uas_submit_sense_urb(struct scsi_cmnd *cmnd, gfp_t gfp)
511 {
512 	struct uas_dev_info *devinfo = cmnd->device->hostdata;
513 	struct urb *urb;
514 	int err;
515 
516 	urb = uas_alloc_sense_urb(devinfo, gfp, cmnd);
517 	if (!urb)
518 		return NULL;
519 	usb_anchor_urb(urb, &devinfo->sense_urbs);
520 	err = usb_submit_urb(urb, gfp);
521 	if (err) {
522 		usb_unanchor_urb(urb);
523 		uas_log_cmd_state(cmnd, "sense submit err", err);
524 		usb_free_urb(urb);
525 		return NULL;
526 	}
527 	return urb;
528 }
529 
530 static int uas_submit_urbs(struct scsi_cmnd *cmnd,
531 			   struct uas_dev_info *devinfo)
532 {
533 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
534 	struct urb *urb;
535 	int err;
536 
537 	lockdep_assert_held(&devinfo->lock);
538 	if (cmdinfo->state & SUBMIT_STATUS_URB) {
539 		urb = uas_submit_sense_urb(cmnd, GFP_ATOMIC);
540 		if (!urb)
541 			return SCSI_MLQUEUE_DEVICE_BUSY;
542 		cmdinfo->state &= ~SUBMIT_STATUS_URB;
543 	}
544 
545 	if (cmdinfo->state & ALLOC_DATA_IN_URB) {
546 		cmdinfo->data_in_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
547 							cmnd, DMA_FROM_DEVICE);
548 		if (!cmdinfo->data_in_urb)
549 			return SCSI_MLQUEUE_DEVICE_BUSY;
550 		cmdinfo->state &= ~ALLOC_DATA_IN_URB;
551 	}
552 
553 	if (cmdinfo->state & SUBMIT_DATA_IN_URB) {
554 		usb_anchor_urb(cmdinfo->data_in_urb, &devinfo->data_urbs);
555 		err = usb_submit_urb(cmdinfo->data_in_urb, GFP_ATOMIC);
556 		if (err) {
557 			usb_unanchor_urb(cmdinfo->data_in_urb);
558 			uas_log_cmd_state(cmnd, "data in submit err", err);
559 			return SCSI_MLQUEUE_DEVICE_BUSY;
560 		}
561 		cmdinfo->state &= ~SUBMIT_DATA_IN_URB;
562 		cmdinfo->state |= DATA_IN_URB_INFLIGHT;
563 	}
564 
565 	if (cmdinfo->state & ALLOC_DATA_OUT_URB) {
566 		cmdinfo->data_out_urb = uas_alloc_data_urb(devinfo, GFP_ATOMIC,
567 							cmnd, DMA_TO_DEVICE);
568 		if (!cmdinfo->data_out_urb)
569 			return SCSI_MLQUEUE_DEVICE_BUSY;
570 		cmdinfo->state &= ~ALLOC_DATA_OUT_URB;
571 	}
572 
573 	if (cmdinfo->state & SUBMIT_DATA_OUT_URB) {
574 		usb_anchor_urb(cmdinfo->data_out_urb, &devinfo->data_urbs);
575 		err = usb_submit_urb(cmdinfo->data_out_urb, GFP_ATOMIC);
576 		if (err) {
577 			usb_unanchor_urb(cmdinfo->data_out_urb);
578 			uas_log_cmd_state(cmnd, "data out submit err", err);
579 			return SCSI_MLQUEUE_DEVICE_BUSY;
580 		}
581 		cmdinfo->state &= ~SUBMIT_DATA_OUT_URB;
582 		cmdinfo->state |= DATA_OUT_URB_INFLIGHT;
583 	}
584 
585 	if (cmdinfo->state & ALLOC_CMD_URB) {
586 		cmdinfo->cmd_urb = uas_alloc_cmd_urb(devinfo, GFP_ATOMIC, cmnd);
587 		if (!cmdinfo->cmd_urb)
588 			return SCSI_MLQUEUE_DEVICE_BUSY;
589 		cmdinfo->state &= ~ALLOC_CMD_URB;
590 	}
591 
592 	if (cmdinfo->state & SUBMIT_CMD_URB) {
593 		usb_anchor_urb(cmdinfo->cmd_urb, &devinfo->cmd_urbs);
594 		err = usb_submit_urb(cmdinfo->cmd_urb, GFP_ATOMIC);
595 		if (err) {
596 			usb_unanchor_urb(cmdinfo->cmd_urb);
597 			uas_log_cmd_state(cmnd, "cmd submit err", err);
598 			return SCSI_MLQUEUE_DEVICE_BUSY;
599 		}
600 		cmdinfo->cmd_urb = NULL;
601 		cmdinfo->state &= ~SUBMIT_CMD_URB;
602 		cmdinfo->state |= COMMAND_INFLIGHT;
603 	}
604 
605 	return 0;
606 }
607 
608 static int uas_queuecommand_lck(struct scsi_cmnd *cmnd,
609 					void (*done)(struct scsi_cmnd *))
610 {
611 	struct scsi_device *sdev = cmnd->device;
612 	struct uas_dev_info *devinfo = sdev->hostdata;
613 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
614 	unsigned long flags;
615 	int idx, err;
616 
617 	BUILD_BUG_ON(sizeof(struct uas_cmd_info) > sizeof(struct scsi_pointer));
618 
619 	/* Re-check scsi_block_requests now that we've the host-lock */
620 	if (cmnd->device->host->host_self_blocked)
621 		return SCSI_MLQUEUE_DEVICE_BUSY;
622 
623 	if ((devinfo->flags & US_FL_NO_ATA_1X) &&
624 			(cmnd->cmnd[0] == ATA_12 || cmnd->cmnd[0] == ATA_16)) {
625 		memcpy(cmnd->sense_buffer, usb_stor_sense_invalidCDB,
626 		       sizeof(usb_stor_sense_invalidCDB));
627 		cmnd->result = SAM_STAT_CHECK_CONDITION;
628 		cmnd->scsi_done(cmnd);
629 		return 0;
630 	}
631 
632 	spin_lock_irqsave(&devinfo->lock, flags);
633 
634 	if (devinfo->resetting) {
635 		cmnd->result = DID_ERROR << 16;
636 		cmnd->scsi_done(cmnd);
637 		spin_unlock_irqrestore(&devinfo->lock, flags);
638 		return 0;
639 	}
640 
641 	/* Find a free uas-tag */
642 	for (idx = 0; idx < devinfo->qdepth; idx++) {
643 		if (!devinfo->cmnd[idx])
644 			break;
645 	}
646 	if (idx == devinfo->qdepth) {
647 		spin_unlock_irqrestore(&devinfo->lock, flags);
648 		return SCSI_MLQUEUE_DEVICE_BUSY;
649 	}
650 
651 	cmnd->scsi_done = done;
652 
653 	memset(cmdinfo, 0, sizeof(*cmdinfo));
654 	cmdinfo->uas_tag = idx + 1; /* uas-tag == usb-stream-id, so 1 based */
655 	cmdinfo->state = SUBMIT_STATUS_URB | ALLOC_CMD_URB | SUBMIT_CMD_URB;
656 
657 	switch (cmnd->sc_data_direction) {
658 	case DMA_FROM_DEVICE:
659 		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
660 		break;
661 	case DMA_BIDIRECTIONAL:
662 		cmdinfo->state |= ALLOC_DATA_IN_URB | SUBMIT_DATA_IN_URB;
663 		/* fall through */
664 	case DMA_TO_DEVICE:
665 		cmdinfo->state |= ALLOC_DATA_OUT_URB | SUBMIT_DATA_OUT_URB;
666 	case DMA_NONE:
667 		break;
668 	}
669 
670 	if (!devinfo->use_streams)
671 		cmdinfo->state &= ~(SUBMIT_DATA_IN_URB | SUBMIT_DATA_OUT_URB);
672 
673 	err = uas_submit_urbs(cmnd, devinfo);
674 	if (err) {
675 		/* If we did nothing, give up now */
676 		if (cmdinfo->state & SUBMIT_STATUS_URB) {
677 			spin_unlock_irqrestore(&devinfo->lock, flags);
678 			return SCSI_MLQUEUE_DEVICE_BUSY;
679 		}
680 		uas_add_work(cmdinfo);
681 	}
682 
683 	devinfo->cmnd[idx] = cmnd;
684 	spin_unlock_irqrestore(&devinfo->lock, flags);
685 	return 0;
686 }
687 
688 static DEF_SCSI_QCMD(uas_queuecommand)
689 
690 /*
691  * For now we do not support actually sending an abort to the device, so
692  * this eh always fails. Still we must define it to make sure that we've
693  * dropped all references to the cmnd in question once this function exits.
694  */
695 static int uas_eh_abort_handler(struct scsi_cmnd *cmnd)
696 {
697 	struct uas_cmd_info *cmdinfo = (void *)&cmnd->SCp;
698 	struct uas_dev_info *devinfo = (void *)cmnd->device->hostdata;
699 	struct urb *data_in_urb = NULL;
700 	struct urb *data_out_urb = NULL;
701 	unsigned long flags;
702 
703 	spin_lock_irqsave(&devinfo->lock, flags);
704 
705 	uas_log_cmd_state(cmnd, __func__, 0);
706 
707 	/* Ensure that try_complete does not call scsi_done */
708 	cmdinfo->state |= COMMAND_ABORTED;
709 
710 	/* Drop all refs to this cmnd, kill data urbs to break their ref */
711 	devinfo->cmnd[cmdinfo->uas_tag - 1] = NULL;
712 	if (cmdinfo->state & DATA_IN_URB_INFLIGHT)
713 		data_in_urb = usb_get_urb(cmdinfo->data_in_urb);
714 	if (cmdinfo->state & DATA_OUT_URB_INFLIGHT)
715 		data_out_urb = usb_get_urb(cmdinfo->data_out_urb);
716 
717 	uas_free_unsubmitted_urbs(cmnd);
718 
719 	spin_unlock_irqrestore(&devinfo->lock, flags);
720 
721 	if (data_in_urb) {
722 		usb_kill_urb(data_in_urb);
723 		usb_put_urb(data_in_urb);
724 	}
725 	if (data_out_urb) {
726 		usb_kill_urb(data_out_urb);
727 		usb_put_urb(data_out_urb);
728 	}
729 
730 	return FAILED;
731 }
732 
733 static int uas_eh_device_reset_handler(struct scsi_cmnd *cmnd)
734 {
735 	struct scsi_device *sdev = cmnd->device;
736 	struct uas_dev_info *devinfo = sdev->hostdata;
737 	struct usb_device *udev = devinfo->udev;
738 	unsigned long flags;
739 	int err;
740 
741 	err = usb_lock_device_for_reset(udev, devinfo->intf);
742 	if (err) {
743 		shost_printk(KERN_ERR, sdev->host,
744 			     "%s FAILED to get lock err %d\n", __func__, err);
745 		return FAILED;
746 	}
747 
748 	shost_printk(KERN_INFO, sdev->host, "%s start\n", __func__);
749 
750 	spin_lock_irqsave(&devinfo->lock, flags);
751 	devinfo->resetting = 1;
752 	spin_unlock_irqrestore(&devinfo->lock, flags);
753 
754 	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
755 	usb_kill_anchored_urbs(&devinfo->sense_urbs);
756 	usb_kill_anchored_urbs(&devinfo->data_urbs);
757 	uas_zap_pending(devinfo, DID_RESET);
758 
759 	err = usb_reset_device(udev);
760 
761 	spin_lock_irqsave(&devinfo->lock, flags);
762 	devinfo->resetting = 0;
763 	spin_unlock_irqrestore(&devinfo->lock, flags);
764 
765 	usb_unlock_device(udev);
766 
767 	if (err) {
768 		shost_printk(KERN_INFO, sdev->host, "%s FAILED err %d\n",
769 			     __func__, err);
770 		return FAILED;
771 	}
772 
773 	shost_printk(KERN_INFO, sdev->host, "%s success\n", __func__);
774 	return SUCCESS;
775 }
776 
777 static int uas_target_alloc(struct scsi_target *starget)
778 {
779 	struct uas_dev_info *devinfo = (struct uas_dev_info *)
780 			dev_to_shost(starget->dev.parent)->hostdata;
781 
782 	if (devinfo->flags & US_FL_NO_REPORT_LUNS)
783 		starget->no_report_luns = 1;
784 
785 	return 0;
786 }
787 
788 static int uas_slave_alloc(struct scsi_device *sdev)
789 {
790 	struct uas_dev_info *devinfo =
791 		(struct uas_dev_info *)sdev->host->hostdata;
792 
793 	sdev->hostdata = devinfo;
794 
795 	/*
796 	 * The protocol has no requirements on alignment in the strict sense.
797 	 * Controllers may or may not have alignment restrictions.
798 	 * As this is not exported, we use an extremely conservative guess.
799 	 */
800 	blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
801 
802 	if (devinfo->flags & US_FL_MAX_SECTORS_64)
803 		blk_queue_max_hw_sectors(sdev->request_queue, 64);
804 	else if (devinfo->flags & US_FL_MAX_SECTORS_240)
805 		blk_queue_max_hw_sectors(sdev->request_queue, 240);
806 
807 	return 0;
808 }
809 
810 static int uas_slave_configure(struct scsi_device *sdev)
811 {
812 	struct uas_dev_info *devinfo = sdev->hostdata;
813 
814 	if (devinfo->flags & US_FL_NO_REPORT_OPCODES)
815 		sdev->no_report_opcodes = 1;
816 
817 	/* A few buggy USB-ATA bridges don't understand FUA */
818 	if (devinfo->flags & US_FL_BROKEN_FUA)
819 		sdev->broken_fua = 1;
820 
821 	/* UAS also needs to support FL_ALWAYS_SYNC */
822 	if (devinfo->flags & US_FL_ALWAYS_SYNC) {
823 		sdev->skip_ms_page_3f = 1;
824 		sdev->skip_ms_page_8 = 1;
825 		sdev->wce_default_on = 1;
826 	}
827 
828 	/* Some disks cannot handle READ_CAPACITY_16 */
829 	if (devinfo->flags & US_FL_NO_READ_CAPACITY_16)
830 		sdev->no_read_capacity_16 = 1;
831 
832 	/*
833 	 * Some disks return the total number of blocks in response
834 	 * to READ CAPACITY rather than the highest block number.
835 	 * If this device makes that mistake, tell the sd driver.
836 	 */
837 	if (devinfo->flags & US_FL_FIX_CAPACITY)
838 		sdev->fix_capacity = 1;
839 
840 	/*
841 	 * in some cases we have to guess
842 	 */
843 	if (devinfo->flags & US_FL_CAPACITY_HEURISTICS)
844 		sdev->guess_capacity = 1;
845 
846 	/*
847 	 * Some devices don't like MODE SENSE with page=0x3f,
848 	 * which is the command used for checking if a device
849 	 * is write-protected.  Now that we tell the sd driver
850 	 * to do a 192-byte transfer with this command the
851 	 * majority of devices work fine, but a few still can't
852 	 * handle it.  The sd driver will simply assume those
853 	 * devices are write-enabled.
854 	 */
855 	if (devinfo->flags & US_FL_NO_WP_DETECT)
856 		sdev->skip_ms_page_3f = 1;
857 
858 	scsi_change_queue_depth(sdev, devinfo->qdepth - 2);
859 	return 0;
860 }
861 
862 static struct scsi_host_template uas_host_template = {
863 	.module = THIS_MODULE,
864 	.name = "uas",
865 	.queuecommand = uas_queuecommand,
866 	.target_alloc = uas_target_alloc,
867 	.slave_alloc = uas_slave_alloc,
868 	.slave_configure = uas_slave_configure,
869 	.eh_abort_handler = uas_eh_abort_handler,
870 	.eh_device_reset_handler = uas_eh_device_reset_handler,
871 	.this_id = -1,
872 	.skip_settle_delay = 1,
873 	.dma_boundary = PAGE_SIZE - 1,
874 };
875 
876 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
877 		    vendorName, productName, useProtocol, useTransport, \
878 		    initFunction, flags) \
879 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
880 	.driver_info = (flags) }
881 
882 static struct usb_device_id uas_usb_ids[] = {
883 #	include "unusual_uas.h"
884 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_BULK) },
885 	{ USB_INTERFACE_INFO(USB_CLASS_MASS_STORAGE, USB_SC_SCSI, USB_PR_UAS) },
886 	{ }
887 };
888 MODULE_DEVICE_TABLE(usb, uas_usb_ids);
889 
890 #undef UNUSUAL_DEV
891 
892 static int uas_switch_interface(struct usb_device *udev,
893 				struct usb_interface *intf)
894 {
895 	struct usb_host_interface *alt;
896 
897 	alt = uas_find_uas_alt_setting(intf);
898 	if (!alt)
899 		return -ENODEV;
900 
901 	return usb_set_interface(udev, alt->desc.bInterfaceNumber,
902 			alt->desc.bAlternateSetting);
903 }
904 
905 static int uas_configure_endpoints(struct uas_dev_info *devinfo)
906 {
907 	struct usb_host_endpoint *eps[4] = { };
908 	struct usb_device *udev = devinfo->udev;
909 	int r;
910 
911 	r = uas_find_endpoints(devinfo->intf->cur_altsetting, eps);
912 	if (r)
913 		return r;
914 
915 	devinfo->cmd_pipe = usb_sndbulkpipe(udev,
916 					    usb_endpoint_num(&eps[0]->desc));
917 	devinfo->status_pipe = usb_rcvbulkpipe(udev,
918 					    usb_endpoint_num(&eps[1]->desc));
919 	devinfo->data_in_pipe = usb_rcvbulkpipe(udev,
920 					    usb_endpoint_num(&eps[2]->desc));
921 	devinfo->data_out_pipe = usb_sndbulkpipe(udev,
922 					    usb_endpoint_num(&eps[3]->desc));
923 
924 	if (udev->speed < USB_SPEED_SUPER) {
925 		devinfo->qdepth = 32;
926 		devinfo->use_streams = 0;
927 	} else {
928 		devinfo->qdepth = usb_alloc_streams(devinfo->intf, eps + 1,
929 						    3, MAX_CMNDS, GFP_NOIO);
930 		if (devinfo->qdepth < 0)
931 			return devinfo->qdepth;
932 		devinfo->use_streams = 1;
933 	}
934 
935 	return 0;
936 }
937 
938 static void uas_free_streams(struct uas_dev_info *devinfo)
939 {
940 	struct usb_device *udev = devinfo->udev;
941 	struct usb_host_endpoint *eps[3];
942 
943 	eps[0] = usb_pipe_endpoint(udev, devinfo->status_pipe);
944 	eps[1] = usb_pipe_endpoint(udev, devinfo->data_in_pipe);
945 	eps[2] = usb_pipe_endpoint(udev, devinfo->data_out_pipe);
946 	usb_free_streams(devinfo->intf, eps, 3, GFP_NOIO);
947 }
948 
949 static int uas_probe(struct usb_interface *intf, const struct usb_device_id *id)
950 {
951 	int result = -ENOMEM;
952 	struct Scsi_Host *shost = NULL;
953 	struct uas_dev_info *devinfo;
954 	struct usb_device *udev = interface_to_usbdev(intf);
955 	unsigned long dev_flags;
956 
957 	if (!uas_use_uas_driver(intf, id, &dev_flags))
958 		return -ENODEV;
959 
960 	if (uas_switch_interface(udev, intf))
961 		return -ENODEV;
962 
963 	shost = scsi_host_alloc(&uas_host_template,
964 				sizeof(struct uas_dev_info));
965 	if (!shost)
966 		goto set_alt0;
967 
968 	shost->max_cmd_len = 16 + 252;
969 	shost->max_id = 1;
970 	shost->max_lun = 256;
971 	shost->max_channel = 0;
972 	shost->sg_tablesize = udev->bus->sg_tablesize;
973 
974 	devinfo = (struct uas_dev_info *)shost->hostdata;
975 	devinfo->intf = intf;
976 	devinfo->udev = udev;
977 	devinfo->resetting = 0;
978 	devinfo->shutdown = 0;
979 	devinfo->flags = dev_flags;
980 	init_usb_anchor(&devinfo->cmd_urbs);
981 	init_usb_anchor(&devinfo->sense_urbs);
982 	init_usb_anchor(&devinfo->data_urbs);
983 	spin_lock_init(&devinfo->lock);
984 	INIT_WORK(&devinfo->work, uas_do_work);
985 
986 	result = uas_configure_endpoints(devinfo);
987 	if (result)
988 		goto set_alt0;
989 
990 	/*
991 	 * 1 tag is reserved for untagged commands +
992 	 * 1 tag to avoid off by one errors in some bridge firmwares
993 	 */
994 	shost->can_queue = devinfo->qdepth - 2;
995 
996 	usb_set_intfdata(intf, shost);
997 	result = scsi_add_host(shost, &intf->dev);
998 	if (result)
999 		goto free_streams;
1000 
1001 	scsi_scan_host(shost);
1002 	return result;
1003 
1004 free_streams:
1005 	uas_free_streams(devinfo);
1006 	usb_set_intfdata(intf, NULL);
1007 set_alt0:
1008 	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1009 	if (shost)
1010 		scsi_host_put(shost);
1011 	return result;
1012 }
1013 
1014 static int uas_cmnd_list_empty(struct uas_dev_info *devinfo)
1015 {
1016 	unsigned long flags;
1017 	int i, r = 1;
1018 
1019 	spin_lock_irqsave(&devinfo->lock, flags);
1020 
1021 	for (i = 0; i < devinfo->qdepth; i++) {
1022 		if (devinfo->cmnd[i]) {
1023 			r = 0; /* Not empty */
1024 			break;
1025 		}
1026 	}
1027 
1028 	spin_unlock_irqrestore(&devinfo->lock, flags);
1029 
1030 	return r;
1031 }
1032 
1033 /*
1034  * Wait for any pending cmnds to complete, on usb-2 sense_urbs may temporarily
1035  * get empty while there still is more work to do due to sense-urbs completing
1036  * with a READ/WRITE_READY iu code, so keep waiting until the list gets empty.
1037  */
1038 static int uas_wait_for_pending_cmnds(struct uas_dev_info *devinfo)
1039 {
1040 	unsigned long start_time;
1041 	int r;
1042 
1043 	start_time = jiffies;
1044 	do {
1045 		flush_work(&devinfo->work);
1046 
1047 		r = usb_wait_anchor_empty_timeout(&devinfo->sense_urbs, 5000);
1048 		if (r == 0)
1049 			return -ETIME;
1050 
1051 		r = usb_wait_anchor_empty_timeout(&devinfo->data_urbs, 500);
1052 		if (r == 0)
1053 			return -ETIME;
1054 
1055 		if (time_after(jiffies, start_time + 5 * HZ))
1056 			return -ETIME;
1057 	} while (!uas_cmnd_list_empty(devinfo));
1058 
1059 	return 0;
1060 }
1061 
1062 static int uas_pre_reset(struct usb_interface *intf)
1063 {
1064 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1065 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1066 	unsigned long flags;
1067 
1068 	if (devinfo->shutdown)
1069 		return 0;
1070 
1071 	/* Block new requests */
1072 	spin_lock_irqsave(shost->host_lock, flags);
1073 	scsi_block_requests(shost);
1074 	spin_unlock_irqrestore(shost->host_lock, flags);
1075 
1076 	if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1077 		shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1078 		scsi_unblock_requests(shost);
1079 		return 1;
1080 	}
1081 
1082 	uas_free_streams(devinfo);
1083 
1084 	return 0;
1085 }
1086 
1087 static int uas_post_reset(struct usb_interface *intf)
1088 {
1089 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1090 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1091 	unsigned long flags;
1092 	int err;
1093 
1094 	if (devinfo->shutdown)
1095 		return 0;
1096 
1097 	err = uas_configure_endpoints(devinfo);
1098 	if (err && err != -ENODEV)
1099 		shost_printk(KERN_ERR, shost,
1100 			     "%s: alloc streams error %d after reset",
1101 			     __func__, err);
1102 
1103 	/* we must unblock the host in every case lest we deadlock */
1104 	spin_lock_irqsave(shost->host_lock, flags);
1105 	scsi_report_bus_reset(shost, 0);
1106 	spin_unlock_irqrestore(shost->host_lock, flags);
1107 
1108 	scsi_unblock_requests(shost);
1109 
1110 	return err ? 1 : 0;
1111 }
1112 
1113 static int uas_suspend(struct usb_interface *intf, pm_message_t message)
1114 {
1115 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1116 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1117 
1118 	if (uas_wait_for_pending_cmnds(devinfo) != 0) {
1119 		shost_printk(KERN_ERR, shost, "%s: timed out\n", __func__);
1120 		return -ETIME;
1121 	}
1122 
1123 	return 0;
1124 }
1125 
1126 static int uas_resume(struct usb_interface *intf)
1127 {
1128 	return 0;
1129 }
1130 
1131 static int uas_reset_resume(struct usb_interface *intf)
1132 {
1133 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1134 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1135 	unsigned long flags;
1136 	int err;
1137 
1138 	err = uas_configure_endpoints(devinfo);
1139 	if (err) {
1140 		shost_printk(KERN_ERR, shost,
1141 			     "%s: alloc streams error %d after reset",
1142 			     __func__, err);
1143 		return -EIO;
1144 	}
1145 
1146 	spin_lock_irqsave(shost->host_lock, flags);
1147 	scsi_report_bus_reset(shost, 0);
1148 	spin_unlock_irqrestore(shost->host_lock, flags);
1149 
1150 	return 0;
1151 }
1152 
1153 static void uas_disconnect(struct usb_interface *intf)
1154 {
1155 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1156 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1157 	unsigned long flags;
1158 
1159 	spin_lock_irqsave(&devinfo->lock, flags);
1160 	devinfo->resetting = 1;
1161 	spin_unlock_irqrestore(&devinfo->lock, flags);
1162 
1163 	cancel_work_sync(&devinfo->work);
1164 	usb_kill_anchored_urbs(&devinfo->cmd_urbs);
1165 	usb_kill_anchored_urbs(&devinfo->sense_urbs);
1166 	usb_kill_anchored_urbs(&devinfo->data_urbs);
1167 	uas_zap_pending(devinfo, DID_NO_CONNECT);
1168 
1169 	scsi_remove_host(shost);
1170 	uas_free_streams(devinfo);
1171 	scsi_host_put(shost);
1172 }
1173 
1174 /*
1175  * Put the device back in usb-storage mode on shutdown, as some BIOS-es
1176  * hang on reboot when the device is still in uas mode. Note the reset is
1177  * necessary as some devices won't revert to usb-storage mode without it.
1178  */
1179 static void uas_shutdown(struct device *dev)
1180 {
1181 	struct usb_interface *intf = to_usb_interface(dev);
1182 	struct usb_device *udev = interface_to_usbdev(intf);
1183 	struct Scsi_Host *shost = usb_get_intfdata(intf);
1184 	struct uas_dev_info *devinfo = (struct uas_dev_info *)shost->hostdata;
1185 
1186 	if (system_state != SYSTEM_RESTART)
1187 		return;
1188 
1189 	devinfo->shutdown = 1;
1190 	uas_free_streams(devinfo);
1191 	usb_set_interface(udev, intf->altsetting[0].desc.bInterfaceNumber, 0);
1192 	usb_reset_device(udev);
1193 }
1194 
1195 static struct usb_driver uas_driver = {
1196 	.name = "uas",
1197 	.probe = uas_probe,
1198 	.disconnect = uas_disconnect,
1199 	.pre_reset = uas_pre_reset,
1200 	.post_reset = uas_post_reset,
1201 	.suspend = uas_suspend,
1202 	.resume = uas_resume,
1203 	.reset_resume = uas_reset_resume,
1204 	.drvwrap.driver.shutdown = uas_shutdown,
1205 	.id_table = uas_usb_ids,
1206 };
1207 
1208 module_usb_driver(uas_driver);
1209 
1210 MODULE_LICENSE("GPL");
1211 MODULE_IMPORT_NS(USB_STORAGE);
1212 MODULE_AUTHOR(
1213 	"Hans de Goede <hdegoede@redhat.com>, Matthew Wilcox and Sarah Sharp");
1214