xref: /openbmc/linux/drivers/usb/storage/transport.c (revision b627b4ed)
1 /* Driver for USB Mass Storage compliant devices
2  *
3  * Current development and maintenance by:
4  *   (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
5  *
6  * Developed with the assistance of:
7  *   (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
8  *   (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
9  *   (c) 2002 Alan Stern <stern@rowland.org>
10  *
11  * Initial work by:
12  *   (c) 1999 Michael Gee (michael@linuxspecific.com)
13  *
14  * This driver is based on the 'USB Mass Storage Class' document. This
15  * describes in detail the protocol used to communicate with such
16  * devices.  Clearly, the designers had SCSI and ATAPI commands in
17  * mind when they created this document.  The commands are all very
18  * similar to commands in the SCSI-II and ATAPI specifications.
19  *
20  * It is important to note that in a number of cases this class
21  * exhibits class-specific exemptions from the USB specification.
22  * Notably the usage of NAK, STALL and ACK differs from the norm, in
23  * that they are used to communicate wait, failed and OK on commands.
24  *
25  * Also, for certain devices, the interrupt endpoint is used to convey
26  * status of a command.
27  *
28  * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
29  * information about this driver.
30  *
31  * This program is free software; you can redistribute it and/or modify it
32  * under the terms of the GNU General Public License as published by the
33  * Free Software Foundation; either version 2, or (at your option) any
34  * later version.
35  *
36  * This program is distributed in the hope that it will be useful, but
37  * WITHOUT ANY WARRANTY; without even the implied warranty of
38  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
39  * General Public License for more details.
40  *
41  * You should have received a copy of the GNU General Public License along
42  * with this program; if not, write to the Free Software Foundation, Inc.,
43  * 675 Mass Ave, Cambridge, MA 02139, USA.
44  */
45 
46 #include <linux/sched.h>
47 #include <linux/errno.h>
48 #include <linux/slab.h>
49 
50 #include <scsi/scsi.h>
51 #include <scsi/scsi_eh.h>
52 #include <scsi/scsi_device.h>
53 
54 #include "usb.h"
55 #include "transport.h"
56 #include "protocol.h"
57 #include "scsiglue.h"
58 #include "debug.h"
59 
60 #include <linux/blkdev.h>
61 #include "../../scsi/sd.h"
62 
63 
64 /***********************************************************************
65  * Data transfer routines
66  ***********************************************************************/
67 
68 /*
69  * This is subtle, so pay attention:
70  * ---------------------------------
71  * We're very concerned about races with a command abort.  Hanging this code
72  * is a sure fire way to hang the kernel.  (Note that this discussion applies
73  * only to transactions resulting from a scsi queued-command, since only
74  * these transactions are subject to a scsi abort.  Other transactions, such
75  * as those occurring during device-specific initialization, must be handled
76  * by a separate code path.)
77  *
78  * The abort function (usb_storage_command_abort() in scsiglue.c) first
79  * sets the machine state and the ABORTING bit in us->dflags to prevent
80  * new URBs from being submitted.  It then calls usb_stor_stop_transport()
81  * below, which atomically tests-and-clears the URB_ACTIVE bit in us->dflags
82  * to see if the current_urb needs to be stopped.  Likewise, the SG_ACTIVE
83  * bit is tested to see if the current_sg scatter-gather request needs to be
84  * stopped.  The timeout callback routine does much the same thing.
85  *
86  * When a disconnect occurs, the DISCONNECTING bit in us->dflags is set to
87  * prevent new URBs from being submitted, and usb_stor_stop_transport() is
88  * called to stop any ongoing requests.
89  *
90  * The submit function first verifies that the submitting is allowed
91  * (neither ABORTING nor DISCONNECTING bits are set) and that the submit
92  * completes without errors, and only then sets the URB_ACTIVE bit.  This
93  * prevents the stop_transport() function from trying to cancel the URB
94  * while the submit call is underway.  Next, the submit function must test
95  * the flags to see if an abort or disconnect occurred during the submission
96  * or before the URB_ACTIVE bit was set.  If so, it's essential to cancel
97  * the URB if it hasn't been cancelled already (i.e., if the URB_ACTIVE bit
98  * is still set).  Either way, the function must then wait for the URB to
99  * finish.  Note that the URB can still be in progress even after a call to
100  * usb_unlink_urb() returns.
101  *
102  * The idea is that (1) once the ABORTING or DISCONNECTING bit is set,
103  * either the stop_transport() function or the submitting function
104  * is guaranteed to call usb_unlink_urb() for an active URB,
105  * and (2) test_and_clear_bit() prevents usb_unlink_urb() from being
106  * called more than once or from being called during usb_submit_urb().
107  */
108 
109 /* This is the completion handler which will wake us up when an URB
110  * completes.
111  */
112 static void usb_stor_blocking_completion(struct urb *urb)
113 {
114 	struct completion *urb_done_ptr = urb->context;
115 
116 	complete(urb_done_ptr);
117 }
118 
119 /* This is the common part of the URB message submission code
120  *
121  * All URBs from the usb-storage driver involved in handling a queued scsi
122  * command _must_ pass through this function (or something like it) for the
123  * abort mechanisms to work properly.
124  */
125 static int usb_stor_msg_common(struct us_data *us, int timeout)
126 {
127 	struct completion urb_done;
128 	long timeleft;
129 	int status;
130 
131 	/* don't submit URBs during abort processing */
132 	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
133 		return -EIO;
134 
135 	/* set up data structures for the wakeup system */
136 	init_completion(&urb_done);
137 
138 	/* fill the common fields in the URB */
139 	us->current_urb->context = &urb_done;
140 	us->current_urb->actual_length = 0;
141 	us->current_urb->error_count = 0;
142 	us->current_urb->status = 0;
143 
144 	/* we assume that if transfer_buffer isn't us->iobuf then it
145 	 * hasn't been mapped for DMA.  Yes, this is clunky, but it's
146 	 * easier than always having the caller tell us whether the
147 	 * transfer buffer has already been mapped. */
148 	us->current_urb->transfer_flags = URB_NO_SETUP_DMA_MAP;
149 	if (us->current_urb->transfer_buffer == us->iobuf)
150 		us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
151 	us->current_urb->transfer_dma = us->iobuf_dma;
152 	us->current_urb->setup_dma = us->cr_dma;
153 
154 	/* submit the URB */
155 	status = usb_submit_urb(us->current_urb, GFP_NOIO);
156 	if (status) {
157 		/* something went wrong */
158 		return status;
159 	}
160 
161 	/* since the URB has been submitted successfully, it's now okay
162 	 * to cancel it */
163 	set_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
164 
165 	/* did an abort occur during the submission? */
166 	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
167 
168 		/* cancel the URB, if it hasn't been cancelled already */
169 		if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
170 			US_DEBUGP("-- cancelling URB\n");
171 			usb_unlink_urb(us->current_urb);
172 		}
173 	}
174 
175 	/* wait for the completion of the URB */
176 	timeleft = wait_for_completion_interruptible_timeout(
177 			&urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT);
178 
179 	clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
180 
181 	if (timeleft <= 0) {
182 		US_DEBUGP("%s -- cancelling URB\n",
183 			  timeleft == 0 ? "Timeout" : "Signal");
184 		usb_kill_urb(us->current_urb);
185 	}
186 
187 	/* return the URB status */
188 	return us->current_urb->status;
189 }
190 
191 /*
192  * Transfer one control message, with timeouts, and allowing early
193  * termination.  Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
194  */
195 int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
196 		 u8 request, u8 requesttype, u16 value, u16 index,
197 		 void *data, u16 size, int timeout)
198 {
199 	int status;
200 
201 	US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
202 			__func__, request, requesttype,
203 			value, index, size);
204 
205 	/* fill in the devrequest structure */
206 	us->cr->bRequestType = requesttype;
207 	us->cr->bRequest = request;
208 	us->cr->wValue = cpu_to_le16(value);
209 	us->cr->wIndex = cpu_to_le16(index);
210 	us->cr->wLength = cpu_to_le16(size);
211 
212 	/* fill and submit the URB */
213 	usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
214 			 (unsigned char*) us->cr, data, size,
215 			 usb_stor_blocking_completion, NULL);
216 	status = usb_stor_msg_common(us, timeout);
217 
218 	/* return the actual length of the data transferred if no error */
219 	if (status == 0)
220 		status = us->current_urb->actual_length;
221 	return status;
222 }
223 EXPORT_SYMBOL_GPL(usb_stor_control_msg);
224 
225 /* This is a version of usb_clear_halt() that allows early termination and
226  * doesn't read the status from the device -- this is because some devices
227  * crash their internal firmware when the status is requested after a halt.
228  *
229  * A definitive list of these 'bad' devices is too difficult to maintain or
230  * make complete enough to be useful.  This problem was first observed on the
231  * Hagiwara FlashGate DUAL unit.  However, bus traces reveal that neither
232  * MacOS nor Windows checks the status after clearing a halt.
233  *
234  * Since many vendors in this space limit their testing to interoperability
235  * with these two OSes, specification violations like this one are common.
236  */
237 int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
238 {
239 	int result;
240 	int endp = usb_pipeendpoint(pipe);
241 
242 	if (usb_pipein (pipe))
243 		endp |= USB_DIR_IN;
244 
245 	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
246 		USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
247 		USB_ENDPOINT_HALT, endp,
248 		NULL, 0, 3*HZ);
249 
250 	/* reset the endpoint toggle */
251 	if (result >= 0)
252 		usb_settoggle(us->pusb_dev, usb_pipeendpoint(pipe),
253 				usb_pipeout(pipe), 0);
254 
255 	US_DEBUGP("%s: result = %d\n", __func__, result);
256 	return result;
257 }
258 EXPORT_SYMBOL_GPL(usb_stor_clear_halt);
259 
260 
261 /*
262  * Interpret the results of a URB transfer
263  *
264  * This function prints appropriate debugging messages, clears halts on
265  * non-control endpoints, and translates the status to the corresponding
266  * USB_STOR_XFER_xxx return code.
267  */
268 static int interpret_urb_result(struct us_data *us, unsigned int pipe,
269 		unsigned int length, int result, unsigned int partial)
270 {
271 	US_DEBUGP("Status code %d; transferred %u/%u\n",
272 			result, partial, length);
273 	switch (result) {
274 
275 	/* no error code; did we send all the data? */
276 	case 0:
277 		if (partial != length) {
278 			US_DEBUGP("-- short transfer\n");
279 			return USB_STOR_XFER_SHORT;
280 		}
281 
282 		US_DEBUGP("-- transfer complete\n");
283 		return USB_STOR_XFER_GOOD;
284 
285 	/* stalled */
286 	case -EPIPE:
287 		/* for control endpoints, (used by CB[I]) a stall indicates
288 		 * a failed command */
289 		if (usb_pipecontrol(pipe)) {
290 			US_DEBUGP("-- stall on control pipe\n");
291 			return USB_STOR_XFER_STALLED;
292 		}
293 
294 		/* for other sorts of endpoint, clear the stall */
295 		US_DEBUGP("clearing endpoint halt for pipe 0x%x\n", pipe);
296 		if (usb_stor_clear_halt(us, pipe) < 0)
297 			return USB_STOR_XFER_ERROR;
298 		return USB_STOR_XFER_STALLED;
299 
300 	/* babble - the device tried to send more than we wanted to read */
301 	case -EOVERFLOW:
302 		US_DEBUGP("-- babble\n");
303 		return USB_STOR_XFER_LONG;
304 
305 	/* the transfer was cancelled by abort, disconnect, or timeout */
306 	case -ECONNRESET:
307 		US_DEBUGP("-- transfer cancelled\n");
308 		return USB_STOR_XFER_ERROR;
309 
310 	/* short scatter-gather read transfer */
311 	case -EREMOTEIO:
312 		US_DEBUGP("-- short read transfer\n");
313 		return USB_STOR_XFER_SHORT;
314 
315 	/* abort or disconnect in progress */
316 	case -EIO:
317 		US_DEBUGP("-- abort or disconnect in progress\n");
318 		return USB_STOR_XFER_ERROR;
319 
320 	/* the catch-all error case */
321 	default:
322 		US_DEBUGP("-- unknown error\n");
323 		return USB_STOR_XFER_ERROR;
324 	}
325 }
326 
327 /*
328  * Transfer one control message, without timeouts, but allowing early
329  * termination.  Return codes are USB_STOR_XFER_xxx.
330  */
331 int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
332 		u8 request, u8 requesttype, u16 value, u16 index,
333 		void *data, u16 size)
334 {
335 	int result;
336 
337 	US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
338 			__func__, request, requesttype,
339 			value, index, size);
340 
341 	/* fill in the devrequest structure */
342 	us->cr->bRequestType = requesttype;
343 	us->cr->bRequest = request;
344 	us->cr->wValue = cpu_to_le16(value);
345 	us->cr->wIndex = cpu_to_le16(index);
346 	us->cr->wLength = cpu_to_le16(size);
347 
348 	/* fill and submit the URB */
349 	usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
350 			 (unsigned char*) us->cr, data, size,
351 			 usb_stor_blocking_completion, NULL);
352 	result = usb_stor_msg_common(us, 0);
353 
354 	return interpret_urb_result(us, pipe, size, result,
355 			us->current_urb->actual_length);
356 }
357 EXPORT_SYMBOL_GPL(usb_stor_ctrl_transfer);
358 
359 /*
360  * Receive one interrupt buffer, without timeouts, but allowing early
361  * termination.  Return codes are USB_STOR_XFER_xxx.
362  *
363  * This routine always uses us->recv_intr_pipe as the pipe and
364  * us->ep_bInterval as the interrupt interval.
365  */
366 static int usb_stor_intr_transfer(struct us_data *us, void *buf,
367 				  unsigned int length)
368 {
369 	int result;
370 	unsigned int pipe = us->recv_intr_pipe;
371 	unsigned int maxp;
372 
373 	US_DEBUGP("%s: xfer %u bytes\n", __func__, length);
374 
375 	/* calculate the max packet size */
376 	maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe));
377 	if (maxp > length)
378 		maxp = length;
379 
380 	/* fill and submit the URB */
381 	usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
382 			maxp, usb_stor_blocking_completion, NULL,
383 			us->ep_bInterval);
384 	result = usb_stor_msg_common(us, 0);
385 
386 	return interpret_urb_result(us, pipe, length, result,
387 			us->current_urb->actual_length);
388 }
389 
390 /*
391  * Transfer one buffer via bulk pipe, without timeouts, but allowing early
392  * termination.  Return codes are USB_STOR_XFER_xxx.  If the bulk pipe
393  * stalls during the transfer, the halt is automatically cleared.
394  */
395 int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
396 	void *buf, unsigned int length, unsigned int *act_len)
397 {
398 	int result;
399 
400 	US_DEBUGP("%s: xfer %u bytes\n", __func__, length);
401 
402 	/* fill and submit the URB */
403 	usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
404 		      usb_stor_blocking_completion, NULL);
405 	result = usb_stor_msg_common(us, 0);
406 
407 	/* store the actual length of the data transferred */
408 	if (act_len)
409 		*act_len = us->current_urb->actual_length;
410 	return interpret_urb_result(us, pipe, length, result,
411 			us->current_urb->actual_length);
412 }
413 EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_buf);
414 
415 /*
416  * Transfer a scatter-gather list via bulk transfer
417  *
418  * This function does basically the same thing as usb_stor_bulk_transfer_buf()
419  * above, but it uses the usbcore scatter-gather library.
420  */
421 static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
422 		struct scatterlist *sg, int num_sg, unsigned int length,
423 		unsigned int *act_len)
424 {
425 	int result;
426 
427 	/* don't submit s-g requests during abort processing */
428 	if (test_bit(US_FLIDX_ABORTING, &us->dflags))
429 		return USB_STOR_XFER_ERROR;
430 
431 	/* initialize the scatter-gather request block */
432 	US_DEBUGP("%s: xfer %u bytes, %d entries\n", __func__,
433 			length, num_sg);
434 	result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
435 			sg, num_sg, length, GFP_NOIO);
436 	if (result) {
437 		US_DEBUGP("usb_sg_init returned %d\n", result);
438 		return USB_STOR_XFER_ERROR;
439 	}
440 
441 	/* since the block has been initialized successfully, it's now
442 	 * okay to cancel it */
443 	set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
444 
445 	/* did an abort occur during the submission? */
446 	if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
447 
448 		/* cancel the request, if it hasn't been cancelled already */
449 		if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
450 			US_DEBUGP("-- cancelling sg request\n");
451 			usb_sg_cancel(&us->current_sg);
452 		}
453 	}
454 
455 	/* wait for the completion of the transfer */
456 	usb_sg_wait(&us->current_sg);
457 	clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
458 
459 	result = us->current_sg.status;
460 	if (act_len)
461 		*act_len = us->current_sg.bytes;
462 	return interpret_urb_result(us, pipe, length, result,
463 			us->current_sg.bytes);
464 }
465 
466 /*
467  * Common used function. Transfer a complete command
468  * via usb_stor_bulk_transfer_sglist() above. Set cmnd resid
469  */
470 int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
471 		      struct scsi_cmnd* srb)
472 {
473 	unsigned int partial;
474 	int result = usb_stor_bulk_transfer_sglist(us, pipe, scsi_sglist(srb),
475 				      scsi_sg_count(srb), scsi_bufflen(srb),
476 				      &partial);
477 
478 	scsi_set_resid(srb, scsi_bufflen(srb) - partial);
479 	return result;
480 }
481 EXPORT_SYMBOL_GPL(usb_stor_bulk_srb);
482 
483 /*
484  * Transfer an entire SCSI command's worth of data payload over the bulk
485  * pipe.
486  *
487  * Note that this uses usb_stor_bulk_transfer_buf() and
488  * usb_stor_bulk_transfer_sglist() to achieve its goals --
489  * this function simply determines whether we're going to use
490  * scatter-gather or not, and acts appropriately.
491  */
492 int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe,
493 		void *buf, unsigned int length_left, int use_sg, int *residual)
494 {
495 	int result;
496 	unsigned int partial;
497 
498 	/* are we scatter-gathering? */
499 	if (use_sg) {
500 		/* use the usb core scatter-gather primitives */
501 		result = usb_stor_bulk_transfer_sglist(us, pipe,
502 				(struct scatterlist *) buf, use_sg,
503 				length_left, &partial);
504 		length_left -= partial;
505 	} else {
506 		/* no scatter-gather, just make the request */
507 		result = usb_stor_bulk_transfer_buf(us, pipe, buf,
508 				length_left, &partial);
509 		length_left -= partial;
510 	}
511 
512 	/* store the residual and return the error code */
513 	if (residual)
514 		*residual = length_left;
515 	return result;
516 }
517 EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_sg);
518 
519 /***********************************************************************
520  * Transport routines
521  ***********************************************************************/
522 
523 /* There are so many devices that report the capacity incorrectly,
524  * this routine was written to counteract some of the resulting
525  * problems.
526  */
527 static void last_sector_hacks(struct us_data *us, struct scsi_cmnd *srb)
528 {
529 	struct gendisk *disk;
530 	struct scsi_disk *sdkp;
531 	u32 sector;
532 
533 	/* To Report "Medium Error: Record Not Found */
534 	static unsigned char record_not_found[18] = {
535 		[0]	= 0x70,			/* current error */
536 		[2]	= MEDIUM_ERROR,		/* = 0x03 */
537 		[7]	= 0x0a,			/* additional length */
538 		[12]	= 0x14			/* Record Not Found */
539 	};
540 
541 	/* If last-sector problems can't occur, whether because the
542 	 * capacity was already decremented or because the device is
543 	 * known to report the correct capacity, then we don't need
544 	 * to do anything.
545 	 */
546 	if (!us->use_last_sector_hacks)
547 		return;
548 
549 	/* Was this command a READ(10) or a WRITE(10)? */
550 	if (srb->cmnd[0] != READ_10 && srb->cmnd[0] != WRITE_10)
551 		goto done;
552 
553 	/* Did this command access the last sector? */
554 	sector = (srb->cmnd[2] << 24) | (srb->cmnd[3] << 16) |
555 			(srb->cmnd[4] << 8) | (srb->cmnd[5]);
556 	disk = srb->request->rq_disk;
557 	if (!disk)
558 		goto done;
559 	sdkp = scsi_disk(disk);
560 	if (!sdkp)
561 		goto done;
562 	if (sector + 1 != sdkp->capacity)
563 		goto done;
564 
565 	if (srb->result == SAM_STAT_GOOD && scsi_get_resid(srb) == 0) {
566 
567 		/* The command succeeded.  We know this device doesn't
568 		 * have the last-sector bug, so stop checking it.
569 		 */
570 		us->use_last_sector_hacks = 0;
571 
572 	} else {
573 		/* The command failed.  Allow up to 3 retries in case this
574 		 * is some normal sort of failure.  After that, assume the
575 		 * capacity is wrong and we're trying to access the sector
576 		 * beyond the end.  Replace the result code and sense data
577 		 * with values that will cause the SCSI core to fail the
578 		 * command immediately, instead of going into an infinite
579 		 * (or even just a very long) retry loop.
580 		 */
581 		if (++us->last_sector_retries < 3)
582 			return;
583 		srb->result = SAM_STAT_CHECK_CONDITION;
584 		memcpy(srb->sense_buffer, record_not_found,
585 				sizeof(record_not_found));
586 	}
587 
588  done:
589 	/* Don't reset the retry counter for TEST UNIT READY commands,
590 	 * because they get issued after device resets which might be
591 	 * caused by a failed last-sector access.
592 	 */
593 	if (srb->cmnd[0] != TEST_UNIT_READY)
594 		us->last_sector_retries = 0;
595 }
596 
597 /* Invoke the transport and basic error-handling/recovery methods
598  *
599  * This is used by the protocol layers to actually send the message to
600  * the device and receive the response.
601  */
602 void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
603 {
604 	int need_auto_sense;
605 	int result;
606 
607 	/* send the command to the transport layer */
608 	scsi_set_resid(srb, 0);
609 	result = us->transport(srb, us);
610 
611 	/* if the command gets aborted by the higher layers, we need to
612 	 * short-circuit all other processing
613 	 */
614 	if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
615 		US_DEBUGP("-- command was aborted\n");
616 		srb->result = DID_ABORT << 16;
617 		goto Handle_Errors;
618 	}
619 
620 	/* if there is a transport error, reset and don't auto-sense */
621 	if (result == USB_STOR_TRANSPORT_ERROR) {
622 		US_DEBUGP("-- transport indicates error, resetting\n");
623 		srb->result = DID_ERROR << 16;
624 		goto Handle_Errors;
625 	}
626 
627 	/* if the transport provided its own sense data, don't auto-sense */
628 	if (result == USB_STOR_TRANSPORT_NO_SENSE) {
629 		srb->result = SAM_STAT_CHECK_CONDITION;
630 		last_sector_hacks(us, srb);
631 		return;
632 	}
633 
634 	srb->result = SAM_STAT_GOOD;
635 
636 	/* Determine if we need to auto-sense
637 	 *
638 	 * I normally don't use a flag like this, but it's almost impossible
639 	 * to understand what's going on here if I don't.
640 	 */
641 	need_auto_sense = 0;
642 
643 	/*
644 	 * If we're running the CB transport, which is incapable
645 	 * of determining status on its own, we will auto-sense
646 	 * unless the operation involved a data-in transfer.  Devices
647 	 * can signal most data-in errors by stalling the bulk-in pipe.
648 	 */
649 	if ((us->protocol == US_PR_CB || us->protocol == US_PR_DPCM_USB) &&
650 			srb->sc_data_direction != DMA_FROM_DEVICE) {
651 		US_DEBUGP("-- CB transport device requiring auto-sense\n");
652 		need_auto_sense = 1;
653 	}
654 
655 	/*
656 	 * If we have a failure, we're going to do a REQUEST_SENSE
657 	 * automatically.  Note that we differentiate between a command
658 	 * "failure" and an "error" in the transport mechanism.
659 	 */
660 	if (result == USB_STOR_TRANSPORT_FAILED) {
661 		US_DEBUGP("-- transport indicates command failure\n");
662 		need_auto_sense = 1;
663 	}
664 
665 	/*
666 	 * Determine if this device is SAT by seeing if the
667 	 * command executed successfully.  Otherwise we'll have
668 	 * to wait for at least one CHECK_CONDITION to determine
669 	 * SANE_SENSE support
670 	 */
671 	if ((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
672 	    result == USB_STOR_TRANSPORT_GOOD &&
673 	    !(us->fflags & US_FL_SANE_SENSE) &&
674 	    !(srb->cmnd[2] & 0x20)) {
675 		US_DEBUGP("-- SAT supported, increasing auto-sense\n");
676 		us->fflags |= US_FL_SANE_SENSE;
677 	}
678 
679 	/*
680 	 * A short transfer on a command where we don't expect it
681 	 * is unusual, but it doesn't mean we need to auto-sense.
682 	 */
683 	if ((scsi_get_resid(srb) > 0) &&
684 	    !((srb->cmnd[0] == REQUEST_SENSE) ||
685 	      (srb->cmnd[0] == INQUIRY) ||
686 	      (srb->cmnd[0] == MODE_SENSE) ||
687 	      (srb->cmnd[0] == LOG_SENSE) ||
688 	      (srb->cmnd[0] == MODE_SENSE_10))) {
689 		US_DEBUGP("-- unexpectedly short transfer\n");
690 	}
691 
692 	/* Now, if we need to do the auto-sense, let's do it */
693 	if (need_auto_sense) {
694 		int temp_result;
695 		struct scsi_eh_save ses;
696 		int sense_size = US_SENSE_SIZE;
697 
698 		/* device supports and needs bigger sense buffer */
699 		if (us->fflags & US_FL_SANE_SENSE)
700 			sense_size = ~0;
701 
702 		US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
703 
704 		scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sense_size);
705 
706 		/* FIXME: we must do the protocol translation here */
707 		if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI ||
708 				us->subclass == US_SC_CYP_ATACB)
709 			srb->cmd_len = 6;
710 		else
711 			srb->cmd_len = 12;
712 
713 		/* issue the auto-sense command */
714 		scsi_set_resid(srb, 0);
715 		temp_result = us->transport(us->srb, us);
716 
717 		/* let's clean up right away */
718 		scsi_eh_restore_cmnd(srb, &ses);
719 
720 		if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
721 			US_DEBUGP("-- auto-sense aborted\n");
722 			srb->result = DID_ABORT << 16;
723 			goto Handle_Errors;
724 		}
725 		if (temp_result != USB_STOR_TRANSPORT_GOOD) {
726 			US_DEBUGP("-- auto-sense failure\n");
727 
728 			/* we skip the reset if this happens to be a
729 			 * multi-target device, since failure of an
730 			 * auto-sense is perfectly valid
731 			 */
732 			srb->result = DID_ERROR << 16;
733 			if (!(us->fflags & US_FL_SCM_MULT_TARG))
734 				goto Handle_Errors;
735 			return;
736 		}
737 
738 		/* If the sense data returned is larger than 18-bytes then we
739 		 * assume this device supports requesting more in the future.
740 		 * The response code must be 70h through 73h inclusive.
741 		 */
742 		if (srb->sense_buffer[7] > (US_SENSE_SIZE - 8) &&
743 		    !(us->fflags & US_FL_SANE_SENSE) &&
744 		    (srb->sense_buffer[0] & 0x7C) == 0x70) {
745 			US_DEBUGP("-- SANE_SENSE support enabled\n");
746 			us->fflags |= US_FL_SANE_SENSE;
747 
748 			/* Indicate to the user that we truncated their sense
749 			 * because we didn't know it supported larger sense.
750 			 */
751 			US_DEBUGP("-- Sense data truncated to %i from %i\n",
752 			          US_SENSE_SIZE,
753 			          srb->sense_buffer[7] + 8);
754 			srb->sense_buffer[7] = (US_SENSE_SIZE - 8);
755 		}
756 
757 		US_DEBUGP("-- Result from auto-sense is %d\n", temp_result);
758 		US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
759 			  srb->sense_buffer[0],
760 			  srb->sense_buffer[2] & 0xf,
761 			  srb->sense_buffer[12],
762 			  srb->sense_buffer[13]);
763 #ifdef CONFIG_USB_STORAGE_DEBUG
764 		usb_stor_show_sense(
765 			  srb->sense_buffer[2] & 0xf,
766 			  srb->sense_buffer[12],
767 			  srb->sense_buffer[13]);
768 #endif
769 
770 		/* set the result so the higher layers expect this data */
771 		srb->result = SAM_STAT_CHECK_CONDITION;
772 
773 		/* If things are really okay, then let's show that.  Zero
774 		 * out the sense buffer so the higher layers won't realize
775 		 * we did an unsolicited auto-sense. */
776 		if (result == USB_STOR_TRANSPORT_GOOD &&
777 			/* Filemark 0, ignore EOM, ILI 0, no sense */
778 				(srb->sense_buffer[2] & 0xaf) == 0 &&
779 			/* No ASC or ASCQ */
780 				srb->sense_buffer[12] == 0 &&
781 				srb->sense_buffer[13] == 0) {
782 			srb->result = SAM_STAT_GOOD;
783 			srb->sense_buffer[0] = 0x0;
784 		}
785 	}
786 
787 	/* Did we transfer less than the minimum amount required? */
788 	if ((srb->result == SAM_STAT_GOOD || srb->sense_buffer[2] == 0) &&
789 			scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow)
790 		srb->result = DID_ERROR << 16;
791 
792 	last_sector_hacks(us, srb);
793 	return;
794 
795 	/* Error and abort processing: try to resynchronize with the device
796 	 * by issuing a port reset.  If that fails, try a class-specific
797 	 * device reset. */
798   Handle_Errors:
799 
800 	/* Set the RESETTING bit, and clear the ABORTING bit so that
801 	 * the reset may proceed. */
802 	scsi_lock(us_to_host(us));
803 	set_bit(US_FLIDX_RESETTING, &us->dflags);
804 	clear_bit(US_FLIDX_ABORTING, &us->dflags);
805 	scsi_unlock(us_to_host(us));
806 
807 	/* We must release the device lock because the pre_reset routine
808 	 * will want to acquire it. */
809 	mutex_unlock(&us->dev_mutex);
810 	result = usb_stor_port_reset(us);
811 	mutex_lock(&us->dev_mutex);
812 
813 	if (result < 0) {
814 		scsi_lock(us_to_host(us));
815 		usb_stor_report_device_reset(us);
816 		scsi_unlock(us_to_host(us));
817 		us->transport_reset(us);
818 	}
819 	clear_bit(US_FLIDX_RESETTING, &us->dflags);
820 	last_sector_hacks(us, srb);
821 }
822 
823 /* Stop the current URB transfer */
824 void usb_stor_stop_transport(struct us_data *us)
825 {
826 	US_DEBUGP("%s called\n", __func__);
827 
828 	/* If the state machine is blocked waiting for an URB,
829 	 * let's wake it up.  The test_and_clear_bit() call
830 	 * guarantees that if a URB has just been submitted,
831 	 * it won't be cancelled more than once. */
832 	if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
833 		US_DEBUGP("-- cancelling URB\n");
834 		usb_unlink_urb(us->current_urb);
835 	}
836 
837 	/* If we are waiting for a scatter-gather operation, cancel it. */
838 	if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
839 		US_DEBUGP("-- cancelling sg request\n");
840 		usb_sg_cancel(&us->current_sg);
841 	}
842 }
843 
844 /*
845  * Control/Bulk and Control/Bulk/Interrupt transport
846  */
847 
848 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
849 {
850 	unsigned int transfer_length = scsi_bufflen(srb);
851 	unsigned int pipe = 0;
852 	int result;
853 
854 	/* COMMAND STAGE */
855 	/* let's send the command via the control pipe */
856 	result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
857 				      US_CBI_ADSC,
858 				      USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
859 				      us->ifnum, srb->cmnd, srb->cmd_len);
860 
861 	/* check the return code for the command */
862 	US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result);
863 
864 	/* if we stalled the command, it means command failed */
865 	if (result == USB_STOR_XFER_STALLED) {
866 		return USB_STOR_TRANSPORT_FAILED;
867 	}
868 
869 	/* Uh oh... serious problem here */
870 	if (result != USB_STOR_XFER_GOOD) {
871 		return USB_STOR_TRANSPORT_ERROR;
872 	}
873 
874 	/* DATA STAGE */
875 	/* transfer the data payload for this command, if one exists*/
876 	if (transfer_length) {
877 		pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
878 				us->recv_bulk_pipe : us->send_bulk_pipe;
879 		result = usb_stor_bulk_srb(us, pipe, srb);
880 		US_DEBUGP("CBI data stage result is 0x%x\n", result);
881 
882 		/* if we stalled the data transfer it means command failed */
883 		if (result == USB_STOR_XFER_STALLED)
884 			return USB_STOR_TRANSPORT_FAILED;
885 		if (result > USB_STOR_XFER_STALLED)
886 			return USB_STOR_TRANSPORT_ERROR;
887 	}
888 
889 	/* STATUS STAGE */
890 
891 	/* NOTE: CB does not have a status stage.  Silly, I know.  So
892 	 * we have to catch this at a higher level.
893 	 */
894 	if (us->protocol != US_PR_CBI)
895 		return USB_STOR_TRANSPORT_GOOD;
896 
897 	result = usb_stor_intr_transfer(us, us->iobuf, 2);
898 	US_DEBUGP("Got interrupt data (0x%x, 0x%x)\n",
899 			us->iobuf[0], us->iobuf[1]);
900 	if (result != USB_STOR_XFER_GOOD)
901 		return USB_STOR_TRANSPORT_ERROR;
902 
903 	/* UFI gives us ASC and ASCQ, like a request sense
904 	 *
905 	 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI
906 	 * devices, so we ignore the information for those commands.  Note
907 	 * that this means we could be ignoring a real error on these
908 	 * commands, but that can't be helped.
909 	 */
910 	if (us->subclass == US_SC_UFI) {
911 		if (srb->cmnd[0] == REQUEST_SENSE ||
912 		    srb->cmnd[0] == INQUIRY)
913 			return USB_STOR_TRANSPORT_GOOD;
914 		if (us->iobuf[0])
915 			goto Failed;
916 		return USB_STOR_TRANSPORT_GOOD;
917 	}
918 
919 	/* If not UFI, we interpret the data as a result code
920 	 * The first byte should always be a 0x0.
921 	 *
922 	 * Some bogus devices don't follow that rule.  They stuff the ASC
923 	 * into the first byte -- so if it's non-zero, call it a failure.
924 	 */
925 	if (us->iobuf[0]) {
926 		US_DEBUGP("CBI IRQ data showed reserved bType 0x%x\n",
927 				us->iobuf[0]);
928 		goto Failed;
929 
930 	}
931 
932 	/* The second byte & 0x0F should be 0x0 for good, otherwise error */
933 	switch (us->iobuf[1] & 0x0F) {
934 		case 0x00:
935 			return USB_STOR_TRANSPORT_GOOD;
936 		case 0x01:
937 			goto Failed;
938 	}
939 	return USB_STOR_TRANSPORT_ERROR;
940 
941 	/* the CBI spec requires that the bulk pipe must be cleared
942 	 * following any data-in/out command failure (section 2.4.3.1.3)
943 	 */
944   Failed:
945 	if (pipe)
946 		usb_stor_clear_halt(us, pipe);
947 	return USB_STOR_TRANSPORT_FAILED;
948 }
949 EXPORT_SYMBOL_GPL(usb_stor_CB_transport);
950 
951 /*
952  * Bulk only transport
953  */
954 
955 /* Determine what the maximum LUN supported is */
956 int usb_stor_Bulk_max_lun(struct us_data *us)
957 {
958 	int result;
959 
960 	/* issue the command */
961 	us->iobuf[0] = 0;
962 	result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
963 				 US_BULK_GET_MAX_LUN,
964 				 USB_DIR_IN | USB_TYPE_CLASS |
965 				 USB_RECIP_INTERFACE,
966 				 0, us->ifnum, us->iobuf, 1, HZ);
967 
968 	US_DEBUGP("GetMaxLUN command result is %d, data is %d\n",
969 		  result, us->iobuf[0]);
970 
971 	/* if we have a successful request, return the result */
972 	if (result > 0)
973 		return us->iobuf[0];
974 
975 	/*
976 	 * Some devices don't like GetMaxLUN.  They may STALL the control
977 	 * pipe, they may return a zero-length result, they may do nothing at
978 	 * all and timeout, or they may fail in even more bizarrely creative
979 	 * ways.  In these cases the best approach is to use the default
980 	 * value: only one LUN.
981 	 */
982 	return 0;
983 }
984 
985 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
986 {
987 	struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
988 	struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
989 	unsigned int transfer_length = scsi_bufflen(srb);
990 	unsigned int residue;
991 	int result;
992 	int fake_sense = 0;
993 	unsigned int cswlen;
994 	unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
995 
996 	/* Take care of BULK32 devices; set extra byte to 0 */
997 	if (unlikely(us->fflags & US_FL_BULK32)) {
998 		cbwlen = 32;
999 		us->iobuf[31] = 0;
1000 	}
1001 
1002 	/* set up the command wrapper */
1003 	bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
1004 	bcb->DataTransferLength = cpu_to_le32(transfer_length);
1005 	bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0;
1006 	bcb->Tag = ++us->tag;
1007 	bcb->Lun = srb->device->lun;
1008 	if (us->fflags & US_FL_SCM_MULT_TARG)
1009 		bcb->Lun |= srb->device->id << 4;
1010 	bcb->Length = srb->cmd_len;
1011 
1012 	/* copy the command payload */
1013 	memset(bcb->CDB, 0, sizeof(bcb->CDB));
1014 	memcpy(bcb->CDB, srb->cmnd, bcb->Length);
1015 
1016 	/* send it to out endpoint */
1017 	US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
1018 			le32_to_cpu(bcb->Signature), bcb->Tag,
1019 			le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
1020 			(bcb->Lun >> 4), (bcb->Lun & 0x0F),
1021 			bcb->Length);
1022 	result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
1023 				bcb, cbwlen, NULL);
1024 	US_DEBUGP("Bulk command transfer result=%d\n", result);
1025 	if (result != USB_STOR_XFER_GOOD)
1026 		return USB_STOR_TRANSPORT_ERROR;
1027 
1028 	/* DATA STAGE */
1029 	/* send/receive data payload, if there is any */
1030 
1031 	/* Some USB-IDE converter chips need a 100us delay between the
1032 	 * command phase and the data phase.  Some devices need a little
1033 	 * more than that, probably because of clock rate inaccuracies. */
1034 	if (unlikely(us->fflags & US_FL_GO_SLOW))
1035 		udelay(125);
1036 
1037 	if (transfer_length) {
1038 		unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
1039 				us->recv_bulk_pipe : us->send_bulk_pipe;
1040 		result = usb_stor_bulk_srb(us, pipe, srb);
1041 		US_DEBUGP("Bulk data transfer result 0x%x\n", result);
1042 		if (result == USB_STOR_XFER_ERROR)
1043 			return USB_STOR_TRANSPORT_ERROR;
1044 
1045 		/* If the device tried to send back more data than the
1046 		 * amount requested, the spec requires us to transfer
1047 		 * the CSW anyway.  Since there's no point retrying the
1048 		 * the command, we'll return fake sense data indicating
1049 		 * Illegal Request, Invalid Field in CDB.
1050 		 */
1051 		if (result == USB_STOR_XFER_LONG)
1052 			fake_sense = 1;
1053 	}
1054 
1055 	/* See flow chart on pg 15 of the Bulk Only Transport spec for
1056 	 * an explanation of how this code works.
1057 	 */
1058 
1059 	/* get CSW for device status */
1060 	US_DEBUGP("Attempting to get CSW...\n");
1061 	result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1062 				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1063 
1064 	/* Some broken devices add unnecessary zero-length packets to the
1065 	 * end of their data transfers.  Such packets show up as 0-length
1066 	 * CSWs.  If we encounter such a thing, try to read the CSW again.
1067 	 */
1068 	if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
1069 		US_DEBUGP("Received 0-length CSW; retrying...\n");
1070 		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1071 				bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1072 	}
1073 
1074 	/* did the attempt to read the CSW fail? */
1075 	if (result == USB_STOR_XFER_STALLED) {
1076 
1077 		/* get the status again */
1078 		US_DEBUGP("Attempting to get CSW (2nd try)...\n");
1079 		result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1080 				bcs, US_BULK_CS_WRAP_LEN, NULL);
1081 	}
1082 
1083 	/* if we still have a failure at this point, we're in trouble */
1084 	US_DEBUGP("Bulk status result = %d\n", result);
1085 	if (result != USB_STOR_XFER_GOOD)
1086 		return USB_STOR_TRANSPORT_ERROR;
1087 
1088 	/* check bulk status */
1089 	residue = le32_to_cpu(bcs->Residue);
1090 	US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
1091 			le32_to_cpu(bcs->Signature), bcs->Tag,
1092 			residue, bcs->Status);
1093 	if (!(bcs->Tag == us->tag || (us->fflags & US_FL_BULK_IGNORE_TAG)) ||
1094 		bcs->Status > US_BULK_STAT_PHASE) {
1095 		US_DEBUGP("Bulk logical error\n");
1096 		return USB_STOR_TRANSPORT_ERROR;
1097 	}
1098 
1099 	/* Some broken devices report odd signatures, so we do not check them
1100 	 * for validity against the spec. We store the first one we see,
1101 	 * and check subsequent transfers for validity against this signature.
1102 	 */
1103 	if (!us->bcs_signature) {
1104 		us->bcs_signature = bcs->Signature;
1105 		if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
1106 			US_DEBUGP("Learnt BCS signature 0x%08X\n",
1107 					le32_to_cpu(us->bcs_signature));
1108 	} else if (bcs->Signature != us->bcs_signature) {
1109 		US_DEBUGP("Signature mismatch: got %08X, expecting %08X\n",
1110 			  le32_to_cpu(bcs->Signature),
1111 			  le32_to_cpu(us->bcs_signature));
1112 		return USB_STOR_TRANSPORT_ERROR;
1113 	}
1114 
1115 	/* try to compute the actual residue, based on how much data
1116 	 * was really transferred and what the device tells us */
1117 	if (residue && !(us->fflags & US_FL_IGNORE_RESIDUE)) {
1118 
1119 		/* Heuristically detect devices that generate bogus residues
1120 		 * by seeing what happens with INQUIRY and READ CAPACITY
1121 		 * commands.
1122 		 */
1123 		if (bcs->Status == US_BULK_STAT_OK &&
1124 				scsi_get_resid(srb) == 0 &&
1125 					((srb->cmnd[0] == INQUIRY &&
1126 						transfer_length == 36) ||
1127 					(srb->cmnd[0] == READ_CAPACITY &&
1128 						transfer_length == 8))) {
1129 			us->fflags |= US_FL_IGNORE_RESIDUE;
1130 
1131 		} else {
1132 			residue = min(residue, transfer_length);
1133 			scsi_set_resid(srb, max(scsi_get_resid(srb),
1134 			                                       (int) residue));
1135 		}
1136 	}
1137 
1138 	/* based on the status code, we report good or bad */
1139 	switch (bcs->Status) {
1140 		case US_BULK_STAT_OK:
1141 			/* device babbled -- return fake sense data */
1142 			if (fake_sense) {
1143 				memcpy(srb->sense_buffer,
1144 				       usb_stor_sense_invalidCDB,
1145 				       sizeof(usb_stor_sense_invalidCDB));
1146 				return USB_STOR_TRANSPORT_NO_SENSE;
1147 			}
1148 
1149 			/* command good -- note that data could be short */
1150 			return USB_STOR_TRANSPORT_GOOD;
1151 
1152 		case US_BULK_STAT_FAIL:
1153 			/* command failed */
1154 			return USB_STOR_TRANSPORT_FAILED;
1155 
1156 		case US_BULK_STAT_PHASE:
1157 			/* phase error -- note that a transport reset will be
1158 			 * invoked by the invoke_transport() function
1159 			 */
1160 			return USB_STOR_TRANSPORT_ERROR;
1161 	}
1162 
1163 	/* we should never get here, but if we do, we're in trouble */
1164 	return USB_STOR_TRANSPORT_ERROR;
1165 }
1166 EXPORT_SYMBOL_GPL(usb_stor_Bulk_transport);
1167 
1168 /***********************************************************************
1169  * Reset routines
1170  ***********************************************************************/
1171 
1172 /* This is the common part of the device reset code.
1173  *
1174  * It's handy that every transport mechanism uses the control endpoint for
1175  * resets.
1176  *
1177  * Basically, we send a reset with a 5-second timeout, so we don't get
1178  * jammed attempting to do the reset.
1179  */
1180 static int usb_stor_reset_common(struct us_data *us,
1181 		u8 request, u8 requesttype,
1182 		u16 value, u16 index, void *data, u16 size)
1183 {
1184 	int result;
1185 	int result2;
1186 
1187 	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1188 		US_DEBUGP("No reset during disconnect\n");
1189 		return -EIO;
1190 	}
1191 
1192 	result = usb_stor_control_msg(us, us->send_ctrl_pipe,
1193 			request, requesttype, value, index, data, size,
1194 			5*HZ);
1195 	if (result < 0) {
1196 		US_DEBUGP("Soft reset failed: %d\n", result);
1197 		return result;
1198 	}
1199 
1200 	/* Give the device some time to recover from the reset,
1201 	 * but don't delay disconnect processing. */
1202 	wait_event_interruptible_timeout(us->delay_wait,
1203 			test_bit(US_FLIDX_DISCONNECTING, &us->dflags),
1204 			HZ*6);
1205 	if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1206 		US_DEBUGP("Reset interrupted by disconnect\n");
1207 		return -EIO;
1208 	}
1209 
1210 	US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n");
1211 	result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
1212 
1213 	US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n");
1214 	result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
1215 
1216 	/* return a result code based on the result of the clear-halts */
1217 	if (result >= 0)
1218 		result = result2;
1219 	if (result < 0)
1220 		US_DEBUGP("Soft reset failed\n");
1221 	else
1222 		US_DEBUGP("Soft reset done\n");
1223 	return result;
1224 }
1225 
1226 /* This issues a CB[I] Reset to the device in question
1227  */
1228 #define CB_RESET_CMD_SIZE	12
1229 
1230 int usb_stor_CB_reset(struct us_data *us)
1231 {
1232 	US_DEBUGP("%s called\n", __func__);
1233 
1234 	memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
1235 	us->iobuf[0] = SEND_DIAGNOSTIC;
1236 	us->iobuf[1] = 4;
1237 	return usb_stor_reset_common(us, US_CBI_ADSC,
1238 				 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1239 				 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
1240 }
1241 EXPORT_SYMBOL_GPL(usb_stor_CB_reset);
1242 
1243 /* This issues a Bulk-only Reset to the device in question, including
1244  * clearing the subsequent endpoint halts that may occur.
1245  */
1246 int usb_stor_Bulk_reset(struct us_data *us)
1247 {
1248 	US_DEBUGP("%s called\n", __func__);
1249 
1250 	return usb_stor_reset_common(us, US_BULK_RESET_REQUEST,
1251 				 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1252 				 0, us->ifnum, NULL, 0);
1253 }
1254 EXPORT_SYMBOL_GPL(usb_stor_Bulk_reset);
1255 
1256 /* Issue a USB port reset to the device.  The caller must not hold
1257  * us->dev_mutex.
1258  */
1259 int usb_stor_port_reset(struct us_data *us)
1260 {
1261 	int result;
1262 
1263 	result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
1264 	if (result < 0)
1265 		US_DEBUGP("unable to lock device for reset: %d\n", result);
1266 	else {
1267 		/* Were we disconnected while waiting for the lock? */
1268 		if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1269 			result = -EIO;
1270 			US_DEBUGP("No reset during disconnect\n");
1271 		} else {
1272 			result = usb_reset_device(us->pusb_dev);
1273 			US_DEBUGP("usb_reset_device returns %d\n",
1274 					result);
1275 		}
1276 		usb_unlock_device(us->pusb_dev);
1277 	}
1278 	return result;
1279 }
1280