1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Driver for USB Mass Storage compliant devices
4 *
5 * Current development and maintenance by:
6 * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
7 *
8 * Developed with the assistance of:
9 * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
10 * (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
11 * (c) 2002 Alan Stern <stern@rowland.org>
12 *
13 * Initial work by:
14 * (c) 1999 Michael Gee (michael@linuxspecific.com)
15 *
16 * This driver is based on the 'USB Mass Storage Class' document. This
17 * describes in detail the protocol used to communicate with such
18 * devices. Clearly, the designers had SCSI and ATAPI commands in
19 * mind when they created this document. The commands are all very
20 * similar to commands in the SCSI-II and ATAPI specifications.
21 *
22 * It is important to note that in a number of cases this class
23 * exhibits class-specific exemptions from the USB specification.
24 * Notably the usage of NAK, STALL and ACK differs from the norm, in
25 * that they are used to communicate wait, failed and OK on commands.
26 *
27 * Also, for certain devices, the interrupt endpoint is used to convey
28 * status of a command.
29 */
30
31 #include <linux/sched.h>
32 #include <linux/gfp.h>
33 #include <linux/errno.h>
34 #include <linux/export.h>
35
36 #include <linux/usb/quirks.h>
37
38 #include <scsi/scsi.h>
39 #include <scsi/scsi_eh.h>
40 #include <scsi/scsi_device.h>
41
42 #include "usb.h"
43 #include "transport.h"
44 #include "protocol.h"
45 #include "scsiglue.h"
46 #include "debug.h"
47
48 #include <linux/blkdev.h>
49 #include "../../scsi/sd.h"
50
51
52 /***********************************************************************
53 * Data transfer routines
54 ***********************************************************************/
55
56 /*
57 * This is subtle, so pay attention:
58 * ---------------------------------
59 * We're very concerned about races with a command abort. Hanging this code
60 * is a sure fire way to hang the kernel. (Note that this discussion applies
61 * only to transactions resulting from a scsi queued-command, since only
62 * these transactions are subject to a scsi abort. Other transactions, such
63 * as those occurring during device-specific initialization, must be handled
64 * by a separate code path.)
65 *
66 * The abort function (usb_storage_command_abort() in scsiglue.c) first
67 * sets the machine state and the ABORTING bit in us->dflags to prevent
68 * new URBs from being submitted. It then calls usb_stor_stop_transport()
69 * below, which atomically tests-and-clears the URB_ACTIVE bit in us->dflags
70 * to see if the current_urb needs to be stopped. Likewise, the SG_ACTIVE
71 * bit is tested to see if the current_sg scatter-gather request needs to be
72 * stopped. The timeout callback routine does much the same thing.
73 *
74 * When a disconnect occurs, the DISCONNECTING bit in us->dflags is set to
75 * prevent new URBs from being submitted, and usb_stor_stop_transport() is
76 * called to stop any ongoing requests.
77 *
78 * The submit function first verifies that the submitting is allowed
79 * (neither ABORTING nor DISCONNECTING bits are set) and that the submit
80 * completes without errors, and only then sets the URB_ACTIVE bit. This
81 * prevents the stop_transport() function from trying to cancel the URB
82 * while the submit call is underway. Next, the submit function must test
83 * the flags to see if an abort or disconnect occurred during the submission
84 * or before the URB_ACTIVE bit was set. If so, it's essential to cancel
85 * the URB if it hasn't been cancelled already (i.e., if the URB_ACTIVE bit
86 * is still set). Either way, the function must then wait for the URB to
87 * finish. Note that the URB can still be in progress even after a call to
88 * usb_unlink_urb() returns.
89 *
90 * The idea is that (1) once the ABORTING or DISCONNECTING bit is set,
91 * either the stop_transport() function or the submitting function
92 * is guaranteed to call usb_unlink_urb() for an active URB,
93 * and (2) test_and_clear_bit() prevents usb_unlink_urb() from being
94 * called more than once or from being called during usb_submit_urb().
95 */
96
97 /*
98 * This is the completion handler which will wake us up when an URB
99 * completes.
100 */
101 static void usb_stor_blocking_completion(struct urb *urb)
102 {
103 struct completion *urb_done_ptr = urb->context;
104
105 complete(urb_done_ptr);
106 }
107
108 /*
109 * This is the common part of the URB message submission code
110 *
111 * All URBs from the usb-storage driver involved in handling a queued scsi
112 * command _must_ pass through this function (or something like it) for the
113 * abort mechanisms to work properly.
114 */
115 static int usb_stor_msg_common(struct us_data *us, int timeout)
116 {
117 struct completion urb_done;
118 long timeleft;
119 int status;
120
121 /* don't submit URBs during abort processing */
122 if (test_bit(US_FLIDX_ABORTING, &us->dflags))
123 return -EIO;
124
125 /* set up data structures for the wakeup system */
126 init_completion(&urb_done);
127
128 /* fill the common fields in the URB */
129 us->current_urb->context = &urb_done;
130 us->current_urb->transfer_flags = 0;
131
132 /*
133 * we assume that if transfer_buffer isn't us->iobuf then it
134 * hasn't been mapped for DMA. Yes, this is clunky, but it's
135 * easier than always having the caller tell us whether the
136 * transfer buffer has already been mapped.
137 */
138 if (us->current_urb->transfer_buffer == us->iobuf)
139 us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
140 us->current_urb->transfer_dma = us->iobuf_dma;
141
142 /* submit the URB */
143 status = usb_submit_urb(us->current_urb, GFP_NOIO);
144 if (status) {
145 /* something went wrong */
146 return status;
147 }
148
149 /*
150 * since the URB has been submitted successfully, it's now okay
151 * to cancel it
152 */
153 set_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
154
155 /* did an abort occur during the submission? */
156 if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
157
158 /* cancel the URB, if it hasn't been cancelled already */
159 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
160 usb_stor_dbg(us, "-- cancelling URB\n");
161 usb_unlink_urb(us->current_urb);
162 }
163 }
164
165 /* wait for the completion of the URB */
166 timeleft = wait_for_completion_interruptible_timeout(
167 &urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT);
168
169 clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
170
171 if (timeleft <= 0) {
172 usb_stor_dbg(us, "%s -- cancelling URB\n",
173 timeleft == 0 ? "Timeout" : "Signal");
174 usb_kill_urb(us->current_urb);
175 }
176
177 /* return the URB status */
178 return us->current_urb->status;
179 }
180
181 /*
182 * Transfer one control message, with timeouts, and allowing early
183 * termination. Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
184 */
185 int usb_stor_control_msg(struct us_data *us, unsigned int pipe,
186 u8 request, u8 requesttype, u16 value, u16 index,
187 void *data, u16 size, int timeout)
188 {
189 int status;
190
191 usb_stor_dbg(us, "rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
192 request, requesttype, value, index, size);
193
194 /* fill in the devrequest structure */
195 us->cr->bRequestType = requesttype;
196 us->cr->bRequest = request;
197 us->cr->wValue = cpu_to_le16(value);
198 us->cr->wIndex = cpu_to_le16(index);
199 us->cr->wLength = cpu_to_le16(size);
200
201 /* fill and submit the URB */
202 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
203 (unsigned char*) us->cr, data, size,
204 usb_stor_blocking_completion, NULL);
205 status = usb_stor_msg_common(us, timeout);
206
207 /* return the actual length of the data transferred if no error */
208 if (status == 0)
209 status = us->current_urb->actual_length;
210 return status;
211 }
212 EXPORT_SYMBOL_GPL(usb_stor_control_msg);
213
214 /*
215 * This is a version of usb_clear_halt() that allows early termination and
216 * doesn't read the status from the device -- this is because some devices
217 * crash their internal firmware when the status is requested after a halt.
218 *
219 * A definitive list of these 'bad' devices is too difficult to maintain or
220 * make complete enough to be useful. This problem was first observed on the
221 * Hagiwara FlashGate DUAL unit. However, bus traces reveal that neither
222 * MacOS nor Windows checks the status after clearing a halt.
223 *
224 * Since many vendors in this space limit their testing to interoperability
225 * with these two OSes, specification violations like this one are common.
226 */
227 int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
228 {
229 int result;
230 int endp = usb_pipeendpoint(pipe);
231
232 if (usb_pipein (pipe))
233 endp |= USB_DIR_IN;
234
235 result = usb_stor_control_msg(us, us->send_ctrl_pipe,
236 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT,
237 USB_ENDPOINT_HALT, endp,
238 NULL, 0, 3*HZ);
239
240 if (result >= 0)
241 usb_reset_endpoint(us->pusb_dev, endp);
242
243 usb_stor_dbg(us, "result = %d\n", result);
244 return result;
245 }
246 EXPORT_SYMBOL_GPL(usb_stor_clear_halt);
247
248
249 /*
250 * Interpret the results of a URB transfer
251 *
252 * This function prints appropriate debugging messages, clears halts on
253 * non-control endpoints, and translates the status to the corresponding
254 * USB_STOR_XFER_xxx return code.
255 */
256 static int interpret_urb_result(struct us_data *us, unsigned int pipe,
257 unsigned int length, int result, unsigned int partial)
258 {
259 usb_stor_dbg(us, "Status code %d; transferred %u/%u\n",
260 result, partial, length);
261 switch (result) {
262
263 /* no error code; did we send all the data? */
264 case 0:
265 if (partial != length) {
266 usb_stor_dbg(us, "-- short transfer\n");
267 return USB_STOR_XFER_SHORT;
268 }
269
270 usb_stor_dbg(us, "-- transfer complete\n");
271 return USB_STOR_XFER_GOOD;
272
273 /* stalled */
274 case -EPIPE:
275 /*
276 * for control endpoints, (used by CB[I]) a stall indicates
277 * a failed command
278 */
279 if (usb_pipecontrol(pipe)) {
280 usb_stor_dbg(us, "-- stall on control pipe\n");
281 return USB_STOR_XFER_STALLED;
282 }
283
284 /* for other sorts of endpoint, clear the stall */
285 usb_stor_dbg(us, "clearing endpoint halt for pipe 0x%x\n",
286 pipe);
287 if (usb_stor_clear_halt(us, pipe) < 0)
288 return USB_STOR_XFER_ERROR;
289 return USB_STOR_XFER_STALLED;
290
291 /* babble - the device tried to send more than we wanted to read */
292 case -EOVERFLOW:
293 usb_stor_dbg(us, "-- babble\n");
294 return USB_STOR_XFER_LONG;
295
296 /* the transfer was cancelled by abort, disconnect, or timeout */
297 case -ECONNRESET:
298 usb_stor_dbg(us, "-- transfer cancelled\n");
299 return USB_STOR_XFER_ERROR;
300
301 /* short scatter-gather read transfer */
302 case -EREMOTEIO:
303 usb_stor_dbg(us, "-- short read transfer\n");
304 return USB_STOR_XFER_SHORT;
305
306 /* abort or disconnect in progress */
307 case -EIO:
308 usb_stor_dbg(us, "-- abort or disconnect in progress\n");
309 return USB_STOR_XFER_ERROR;
310
311 /* the catch-all error case */
312 default:
313 usb_stor_dbg(us, "-- unknown error\n");
314 return USB_STOR_XFER_ERROR;
315 }
316 }
317
318 /*
319 * Transfer one control message, without timeouts, but allowing early
320 * termination. Return codes are USB_STOR_XFER_xxx.
321 */
322 int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
323 u8 request, u8 requesttype, u16 value, u16 index,
324 void *data, u16 size)
325 {
326 int result;
327
328 usb_stor_dbg(us, "rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
329 request, requesttype, value, index, size);
330
331 /* fill in the devrequest structure */
332 us->cr->bRequestType = requesttype;
333 us->cr->bRequest = request;
334 us->cr->wValue = cpu_to_le16(value);
335 us->cr->wIndex = cpu_to_le16(index);
336 us->cr->wLength = cpu_to_le16(size);
337
338 /* fill and submit the URB */
339 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
340 (unsigned char*) us->cr, data, size,
341 usb_stor_blocking_completion, NULL);
342 result = usb_stor_msg_common(us, 0);
343
344 return interpret_urb_result(us, pipe, size, result,
345 us->current_urb->actual_length);
346 }
347 EXPORT_SYMBOL_GPL(usb_stor_ctrl_transfer);
348
349 /*
350 * Receive one interrupt buffer, without timeouts, but allowing early
351 * termination. Return codes are USB_STOR_XFER_xxx.
352 *
353 * This routine always uses us->recv_intr_pipe as the pipe and
354 * us->ep_bInterval as the interrupt interval.
355 */
356 static int usb_stor_intr_transfer(struct us_data *us, void *buf,
357 unsigned int length)
358 {
359 int result;
360 unsigned int pipe = us->recv_intr_pipe;
361 unsigned int maxp;
362
363 usb_stor_dbg(us, "xfer %u bytes\n", length);
364
365 /* calculate the max packet size */
366 maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe));
367 if (maxp > length)
368 maxp = length;
369
370 /* fill and submit the URB */
371 usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
372 maxp, usb_stor_blocking_completion, NULL,
373 us->ep_bInterval);
374 result = usb_stor_msg_common(us, 0);
375
376 return interpret_urb_result(us, pipe, length, result,
377 us->current_urb->actual_length);
378 }
379
380 /*
381 * Transfer one buffer via bulk pipe, without timeouts, but allowing early
382 * termination. Return codes are USB_STOR_XFER_xxx. If the bulk pipe
383 * stalls during the transfer, the halt is automatically cleared.
384 */
385 int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
386 void *buf, unsigned int length, unsigned int *act_len)
387 {
388 int result;
389
390 usb_stor_dbg(us, "xfer %u bytes\n", length);
391
392 /* fill and submit the URB */
393 usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
394 usb_stor_blocking_completion, NULL);
395 result = usb_stor_msg_common(us, 0);
396
397 /* store the actual length of the data transferred */
398 if (act_len)
399 *act_len = us->current_urb->actual_length;
400 return interpret_urb_result(us, pipe, length, result,
401 us->current_urb->actual_length);
402 }
403 EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_buf);
404
405 /*
406 * Transfer a scatter-gather list via bulk transfer
407 *
408 * This function does basically the same thing as usb_stor_bulk_transfer_buf()
409 * above, but it uses the usbcore scatter-gather library.
410 */
411 static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
412 struct scatterlist *sg, int num_sg, unsigned int length,
413 unsigned int *act_len)
414 {
415 int result;
416
417 /* don't submit s-g requests during abort processing */
418 if (test_bit(US_FLIDX_ABORTING, &us->dflags))
419 return USB_STOR_XFER_ERROR;
420
421 /* initialize the scatter-gather request block */
422 usb_stor_dbg(us, "xfer %u bytes, %d entries\n", length, num_sg);
423 result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
424 sg, num_sg, length, GFP_NOIO);
425 if (result) {
426 usb_stor_dbg(us, "usb_sg_init returned %d\n", result);
427 return USB_STOR_XFER_ERROR;
428 }
429
430 /*
431 * since the block has been initialized successfully, it's now
432 * okay to cancel it
433 */
434 set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
435
436 /* did an abort occur during the submission? */
437 if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
438
439 /* cancel the request, if it hasn't been cancelled already */
440 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
441 usb_stor_dbg(us, "-- cancelling sg request\n");
442 usb_sg_cancel(&us->current_sg);
443 }
444 }
445
446 /* wait for the completion of the transfer */
447 usb_sg_wait(&us->current_sg);
448 clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
449
450 result = us->current_sg.status;
451 if (act_len)
452 *act_len = us->current_sg.bytes;
453 return interpret_urb_result(us, pipe, length, result,
454 us->current_sg.bytes);
455 }
456
457 /*
458 * Common used function. Transfer a complete command
459 * via usb_stor_bulk_transfer_sglist() above. Set cmnd resid
460 */
461 int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
462 struct scsi_cmnd* srb)
463 {
464 unsigned int partial;
465 int result = usb_stor_bulk_transfer_sglist(us, pipe, scsi_sglist(srb),
466 scsi_sg_count(srb), scsi_bufflen(srb),
467 &partial);
468
469 scsi_set_resid(srb, scsi_bufflen(srb) - partial);
470 return result;
471 }
472 EXPORT_SYMBOL_GPL(usb_stor_bulk_srb);
473
474 /*
475 * Transfer an entire SCSI command's worth of data payload over the bulk
476 * pipe.
477 *
478 * Note that this uses usb_stor_bulk_transfer_buf() and
479 * usb_stor_bulk_transfer_sglist() to achieve its goals --
480 * this function simply determines whether we're going to use
481 * scatter-gather or not, and acts appropriately.
482 */
483 int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe,
484 void *buf, unsigned int length_left, int use_sg, int *residual)
485 {
486 int result;
487 unsigned int partial;
488
489 /* are we scatter-gathering? */
490 if (use_sg) {
491 /* use the usb core scatter-gather primitives */
492 result = usb_stor_bulk_transfer_sglist(us, pipe,
493 (struct scatterlist *) buf, use_sg,
494 length_left, &partial);
495 length_left -= partial;
496 } else {
497 /* no scatter-gather, just make the request */
498 result = usb_stor_bulk_transfer_buf(us, pipe, buf,
499 length_left, &partial);
500 length_left -= partial;
501 }
502
503 /* store the residual and return the error code */
504 if (residual)
505 *residual = length_left;
506 return result;
507 }
508 EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_sg);
509
510 /***********************************************************************
511 * Transport routines
512 ***********************************************************************/
513
514 /*
515 * There are so many devices that report the capacity incorrectly,
516 * this routine was written to counteract some of the resulting
517 * problems.
518 */
519 static void last_sector_hacks(struct us_data *us, struct scsi_cmnd *srb)
520 {
521 struct gendisk *disk;
522 struct scsi_disk *sdkp;
523 u32 sector;
524
525 /* To Report "Medium Error: Record Not Found */
526 static unsigned char record_not_found[18] = {
527 [0] = 0x70, /* current error */
528 [2] = MEDIUM_ERROR, /* = 0x03 */
529 [7] = 0x0a, /* additional length */
530 [12] = 0x14 /* Record Not Found */
531 };
532
533 /*
534 * If last-sector problems can't occur, whether because the
535 * capacity was already decremented or because the device is
536 * known to report the correct capacity, then we don't need
537 * to do anything.
538 */
539 if (!us->use_last_sector_hacks)
540 return;
541
542 /* Was this command a READ(10) or a WRITE(10)? */
543 if (srb->cmnd[0] != READ_10 && srb->cmnd[0] != WRITE_10)
544 goto done;
545
546 /* Did this command access the last sector? */
547 sector = (srb->cmnd[2] << 24) | (srb->cmnd[3] << 16) |
548 (srb->cmnd[4] << 8) | (srb->cmnd[5]);
549 disk = srb->request->rq_disk;
550 if (!disk)
551 goto done;
552 sdkp = scsi_disk(disk);
553 if (!sdkp)
554 goto done;
555 if (sector + 1 != sdkp->capacity)
556 goto done;
557
558 if (srb->result == SAM_STAT_GOOD && scsi_get_resid(srb) == 0) {
559
560 /*
561 * The command succeeded. We know this device doesn't
562 * have the last-sector bug, so stop checking it.
563 */
564 us->use_last_sector_hacks = 0;
565
566 } else {
567 /*
568 * The command failed. Allow up to 3 retries in case this
569 * is some normal sort of failure. After that, assume the
570 * capacity is wrong and we're trying to access the sector
571 * beyond the end. Replace the result code and sense data
572 * with values that will cause the SCSI core to fail the
573 * command immediately, instead of going into an infinite
574 * (or even just a very long) retry loop.
575 */
576 if (++us->last_sector_retries < 3)
577 return;
578 srb->result = SAM_STAT_CHECK_CONDITION;
579 memcpy(srb->sense_buffer, record_not_found,
580 sizeof(record_not_found));
581 }
582
583 done:
584 /*
585 * Don't reset the retry counter for TEST UNIT READY commands,
586 * because they get issued after device resets which might be
587 * caused by a failed last-sector access.
588 */
589 if (srb->cmnd[0] != TEST_UNIT_READY)
590 us->last_sector_retries = 0;
591 }
592
593 /*
594 * Invoke the transport and basic error-handling/recovery methods
595 *
596 * This is used by the protocol layers to actually send the message to
597 * the device and receive the response.
598 */
599 void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
600 {
601 int need_auto_sense;
602 int result;
603
604 /* send the command to the transport layer */
605 scsi_set_resid(srb, 0);
606 result = us->transport(srb, us);
607
608 /*
609 * if the command gets aborted by the higher layers, we need to
610 * short-circuit all other processing
611 */
612 if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
613 usb_stor_dbg(us, "-- command was aborted\n");
614 srb->result = DID_ABORT << 16;
615 goto Handle_Errors;
616 }
617
618 /* if there is a transport error, reset and don't auto-sense */
619 if (result == USB_STOR_TRANSPORT_ERROR) {
620 usb_stor_dbg(us, "-- transport indicates error, resetting\n");
621 srb->result = DID_ERROR << 16;
622 goto Handle_Errors;
623 }
624
625 /* if the transport provided its own sense data, don't auto-sense */
626 if (result == USB_STOR_TRANSPORT_NO_SENSE) {
627 srb->result = SAM_STAT_CHECK_CONDITION;
628 last_sector_hacks(us, srb);
629 return;
630 }
631
632 srb->result = SAM_STAT_GOOD;
633
634 /*
635 * Determine if we need to auto-sense
636 *
637 * I normally don't use a flag like this, but it's almost impossible
638 * to understand what's going on here if I don't.
639 */
640 need_auto_sense = 0;
641
642 /*
643 * If we're running the CB transport, which is incapable
644 * of determining status on its own, we will auto-sense
645 * unless the operation involved a data-in transfer. Devices
646 * can signal most data-in errors by stalling the bulk-in pipe.
647 */
648 if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_DPCM_USB) &&
649 srb->sc_data_direction != DMA_FROM_DEVICE) {
650 usb_stor_dbg(us, "-- CB transport device requiring auto-sense\n");
651 need_auto_sense = 1;
652 }
653
654 /*
655 * If we have a failure, we're going to do a REQUEST_SENSE
656 * automatically. Note that we differentiate between a command
657 * "failure" and an "error" in the transport mechanism.
658 */
659 if (result == USB_STOR_TRANSPORT_FAILED) {
660 usb_stor_dbg(us, "-- transport indicates command failure\n");
661 need_auto_sense = 1;
662 }
663
664 /*
665 * Determine if this device is SAT by seeing if the
666 * command executed successfully. Otherwise we'll have
667 * to wait for at least one CHECK_CONDITION to determine
668 * SANE_SENSE support
669 */
670 if (unlikely((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
671 result == USB_STOR_TRANSPORT_GOOD &&
672 !(us->fflags & US_FL_SANE_SENSE) &&
673 !(us->fflags & US_FL_BAD_SENSE) &&
674 !(srb->cmnd[2] & 0x20))) {
675 usb_stor_dbg(us, "-- 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 usb_stor_dbg(us, "-- 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 struct scsi_sense_hdr sshdr;
698 const u8 *scdd;
699 u8 fm_ili;
700
701 /* device supports and needs bigger sense buffer */
702 if (us->fflags & US_FL_SANE_SENSE)
703 sense_size = ~0;
704 Retry_Sense:
705 usb_stor_dbg(us, "Issuing auto-REQUEST_SENSE\n");
706
707 scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sense_size);
708
709 /* FIXME: we must do the protocol translation here */
710 if (us->subclass == USB_SC_RBC || us->subclass == USB_SC_SCSI ||
711 us->subclass == USB_SC_CYP_ATACB)
712 srb->cmd_len = 6;
713 else
714 srb->cmd_len = 12;
715
716 /* issue the auto-sense command */
717 scsi_set_resid(srb, 0);
718 temp_result = us->transport(us->srb, us);
719
720 /* let's clean up right away */
721 scsi_eh_restore_cmnd(srb, &ses);
722
723 if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
724 usb_stor_dbg(us, "-- auto-sense aborted\n");
725 srb->result = DID_ABORT << 16;
726
727 /* If SANE_SENSE caused this problem, disable it */
728 if (sense_size != US_SENSE_SIZE) {
729 us->fflags &= ~US_FL_SANE_SENSE;
730 us->fflags |= US_FL_BAD_SENSE;
731 }
732 goto Handle_Errors;
733 }
734
735 /*
736 * Some devices claim to support larger sense but fail when
737 * trying to request it. When a transport failure happens
738 * using US_FS_SANE_SENSE, we always retry with a standard
739 * (small) sense request. This fixes some USB GSM modems
740 */
741 if (temp_result == USB_STOR_TRANSPORT_FAILED &&
742 sense_size != US_SENSE_SIZE) {
743 usb_stor_dbg(us, "-- auto-sense failure, retry small sense\n");
744 sense_size = US_SENSE_SIZE;
745 us->fflags &= ~US_FL_SANE_SENSE;
746 us->fflags |= US_FL_BAD_SENSE;
747 goto Retry_Sense;
748 }
749
750 /* Other failures */
751 if (temp_result != USB_STOR_TRANSPORT_GOOD) {
752 usb_stor_dbg(us, "-- auto-sense failure\n");
753
754 /*
755 * we skip the reset if this happens to be a
756 * multi-target device, since failure of an
757 * auto-sense is perfectly valid
758 */
759 srb->result = DID_ERROR << 16;
760 if (!(us->fflags & US_FL_SCM_MULT_TARG))
761 goto Handle_Errors;
762 return;
763 }
764
765 /*
766 * If the sense data returned is larger than 18-bytes then we
767 * assume this device supports requesting more in the future.
768 * The response code must be 70h through 73h inclusive.
769 */
770 if (srb->sense_buffer[7] > (US_SENSE_SIZE - 8) &&
771 !(us->fflags & US_FL_SANE_SENSE) &&
772 !(us->fflags & US_FL_BAD_SENSE) &&
773 (srb->sense_buffer[0] & 0x7C) == 0x70) {
774 usb_stor_dbg(us, "-- SANE_SENSE support enabled\n");
775 us->fflags |= US_FL_SANE_SENSE;
776
777 /*
778 * Indicate to the user that we truncated their sense
779 * because we didn't know it supported larger sense.
780 */
781 usb_stor_dbg(us, "-- Sense data truncated to %i from %i\n",
782 US_SENSE_SIZE,
783 srb->sense_buffer[7] + 8);
784 srb->sense_buffer[7] = (US_SENSE_SIZE - 8);
785 }
786
787 scsi_normalize_sense(srb->sense_buffer, SCSI_SENSE_BUFFERSIZE,
788 &sshdr);
789
790 usb_stor_dbg(us, "-- Result from auto-sense is %d\n",
791 temp_result);
792 usb_stor_dbg(us, "-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
793 sshdr.response_code, sshdr.sense_key,
794 sshdr.asc, sshdr.ascq);
795 #ifdef CONFIG_USB_STORAGE_DEBUG
796 usb_stor_show_sense(us, sshdr.sense_key, sshdr.asc, sshdr.ascq);
797 #endif
798
799 /* set the result so the higher layers expect this data */
800 srb->result = SAM_STAT_CHECK_CONDITION;
801
802 scdd = scsi_sense_desc_find(srb->sense_buffer,
803 SCSI_SENSE_BUFFERSIZE, 4);
804 fm_ili = (scdd ? scdd[3] : srb->sense_buffer[2]) & 0xA0;
805
806 /*
807 * We often get empty sense data. This could indicate that
808 * everything worked or that there was an unspecified
809 * problem. We have to decide which.
810 */
811 if (sshdr.sense_key == 0 && sshdr.asc == 0 && sshdr.ascq == 0 &&
812 fm_ili == 0) {
813 /*
814 * If things are really okay, then let's show that.
815 * Zero out the sense buffer so the higher layers
816 * won't realize we did an unsolicited auto-sense.
817 */
818 if (result == USB_STOR_TRANSPORT_GOOD) {
819 srb->result = SAM_STAT_GOOD;
820 srb->sense_buffer[0] = 0x0;
821 }
822
823 /*
824 * ATA-passthru commands use sense data to report
825 * the command completion status, and often devices
826 * return Check Condition status when nothing is
827 * wrong.
828 */
829 else if (srb->cmnd[0] == ATA_16 ||
830 srb->cmnd[0] == ATA_12) {
831 /* leave the data alone */
832 }
833
834 /*
835 * If there was a problem, report an unspecified
836 * hardware error to prevent the higher layers from
837 * entering an infinite retry loop.
838 */
839 else {
840 srb->result = DID_ERROR << 16;
841 if ((sshdr.response_code & 0x72) == 0x72)
842 srb->sense_buffer[1] = HARDWARE_ERROR;
843 else
844 srb->sense_buffer[2] = HARDWARE_ERROR;
845 }
846 }
847 }
848
849 /*
850 * Some devices don't work or return incorrect data the first
851 * time they get a READ(10) command, or for the first READ(10)
852 * after a media change. If the INITIAL_READ10 flag is set,
853 * keep track of whether READ(10) commands succeed. If the
854 * previous one succeeded and this one failed, set the REDO_READ10
855 * flag to force a retry.
856 */
857 if (unlikely((us->fflags & US_FL_INITIAL_READ10) &&
858 srb->cmnd[0] == READ_10)) {
859 if (srb->result == SAM_STAT_GOOD) {
860 set_bit(US_FLIDX_READ10_WORKED, &us->dflags);
861 } else if (test_bit(US_FLIDX_READ10_WORKED, &us->dflags)) {
862 clear_bit(US_FLIDX_READ10_WORKED, &us->dflags);
863 set_bit(US_FLIDX_REDO_READ10, &us->dflags);
864 }
865
866 /*
867 * Next, if the REDO_READ10 flag is set, return a result
868 * code that will cause the SCSI core to retry the READ(10)
869 * command immediately.
870 */
871 if (test_bit(US_FLIDX_REDO_READ10, &us->dflags)) {
872 clear_bit(US_FLIDX_REDO_READ10, &us->dflags);
873 srb->result = DID_IMM_RETRY << 16;
874 srb->sense_buffer[0] = 0;
875 }
876 }
877
878 /* Did we transfer less than the minimum amount required? */
879 if ((srb->result == SAM_STAT_GOOD || srb->sense_buffer[2] == 0) &&
880 scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow)
881 srb->result = DID_ERROR << 16;
882
883 last_sector_hacks(us, srb);
884 return;
885
886 /*
887 * Error and abort processing: try to resynchronize with the device
888 * by issuing a port reset. If that fails, try a class-specific
889 * device reset.
890 */
891 Handle_Errors:
892
893 /*
894 * Set the RESETTING bit, and clear the ABORTING bit so that
895 * the reset may proceed.
896 */
897 scsi_lock(us_to_host(us));
898 set_bit(US_FLIDX_RESETTING, &us->dflags);
899 clear_bit(US_FLIDX_ABORTING, &us->dflags);
900 scsi_unlock(us_to_host(us));
901
902 /*
903 * We must release the device lock because the pre_reset routine
904 * will want to acquire it.
905 */
906 mutex_unlock(&us->dev_mutex);
907 result = usb_stor_port_reset(us);
908 mutex_lock(&us->dev_mutex);
909
910 if (result < 0) {
911 scsi_lock(us_to_host(us));
912 usb_stor_report_device_reset(us);
913 scsi_unlock(us_to_host(us));
914 us->transport_reset(us);
915 }
916 clear_bit(US_FLIDX_RESETTING, &us->dflags);
917 last_sector_hacks(us, srb);
918 }
919
920 /* Stop the current URB transfer */
921 void usb_stor_stop_transport(struct us_data *us)
922 {
923 /*
924 * If the state machine is blocked waiting for an URB,
925 * let's wake it up. The test_and_clear_bit() call
926 * guarantees that if a URB has just been submitted,
927 * it won't be cancelled more than once.
928 */
929 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
930 usb_stor_dbg(us, "-- cancelling URB\n");
931 usb_unlink_urb(us->current_urb);
932 }
933
934 /* If we are waiting for a scatter-gather operation, cancel it. */
935 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
936 usb_stor_dbg(us, "-- cancelling sg request\n");
937 usb_sg_cancel(&us->current_sg);
938 }
939 }
940
941 /*
942 * Control/Bulk and Control/Bulk/Interrupt transport
943 */
944
945 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
946 {
947 unsigned int transfer_length = scsi_bufflen(srb);
948 unsigned int pipe = 0;
949 int result;
950
951 /* COMMAND STAGE */
952 /* let's send the command via the control pipe */
953 /*
954 * Command is sometime (f.e. after scsi_eh_prep_cmnd) on the stack.
955 * Stack may be vmallocated. So no DMA for us. Make a copy.
956 */
957 memcpy(us->iobuf, srb->cmnd, srb->cmd_len);
958 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
959 US_CBI_ADSC,
960 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
961 us->ifnum, us->iobuf, srb->cmd_len);
962
963 /* check the return code for the command */
964 usb_stor_dbg(us, "Call to usb_stor_ctrl_transfer() returned %d\n",
965 result);
966
967 /* if we stalled the command, it means command failed */
968 if (result == USB_STOR_XFER_STALLED) {
969 return USB_STOR_TRANSPORT_FAILED;
970 }
971
972 /* Uh oh... serious problem here */
973 if (result != USB_STOR_XFER_GOOD) {
974 return USB_STOR_TRANSPORT_ERROR;
975 }
976
977 /* DATA STAGE */
978 /* transfer the data payload for this command, if one exists*/
979 if (transfer_length) {
980 pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
981 us->recv_bulk_pipe : us->send_bulk_pipe;
982 result = usb_stor_bulk_srb(us, pipe, srb);
983 usb_stor_dbg(us, "CBI data stage result is 0x%x\n", result);
984
985 /* if we stalled the data transfer it means command failed */
986 if (result == USB_STOR_XFER_STALLED)
987 return USB_STOR_TRANSPORT_FAILED;
988 if (result > USB_STOR_XFER_STALLED)
989 return USB_STOR_TRANSPORT_ERROR;
990 }
991
992 /* STATUS STAGE */
993
994 /*
995 * NOTE: CB does not have a status stage. Silly, I know. So
996 * we have to catch this at a higher level.
997 */
998 if (us->protocol != USB_PR_CBI)
999 return USB_STOR_TRANSPORT_GOOD;
1000
1001 result = usb_stor_intr_transfer(us, us->iobuf, 2);
1002 usb_stor_dbg(us, "Got interrupt data (0x%x, 0x%x)\n",
1003 us->iobuf[0], us->iobuf[1]);
1004 if (result != USB_STOR_XFER_GOOD)
1005 return USB_STOR_TRANSPORT_ERROR;
1006
1007 /*
1008 * UFI gives us ASC and ASCQ, like a request sense
1009 *
1010 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI
1011 * devices, so we ignore the information for those commands. Note
1012 * that this means we could be ignoring a real error on these
1013 * commands, but that can't be helped.
1014 */
1015 if (us->subclass == USB_SC_UFI) {
1016 if (srb->cmnd[0] == REQUEST_SENSE ||
1017 srb->cmnd[0] == INQUIRY)
1018 return USB_STOR_TRANSPORT_GOOD;
1019 if (us->iobuf[0])
1020 goto Failed;
1021 return USB_STOR_TRANSPORT_GOOD;
1022 }
1023
1024 /*
1025 * If not UFI, we interpret the data as a result code
1026 * The first byte should always be a 0x0.
1027 *
1028 * Some bogus devices don't follow that rule. They stuff the ASC
1029 * into the first byte -- so if it's non-zero, call it a failure.
1030 */
1031 if (us->iobuf[0]) {
1032 usb_stor_dbg(us, "CBI IRQ data showed reserved bType 0x%x\n",
1033 us->iobuf[0]);
1034 goto Failed;
1035
1036 }
1037
1038 /* The second byte & 0x0F should be 0x0 for good, otherwise error */
1039 switch (us->iobuf[1] & 0x0F) {
1040 case 0x00:
1041 return USB_STOR_TRANSPORT_GOOD;
1042 case 0x01:
1043 goto Failed;
1044 }
1045 return USB_STOR_TRANSPORT_ERROR;
1046
1047 /*
1048 * the CBI spec requires that the bulk pipe must be cleared
1049 * following any data-in/out command failure (section 2.4.3.1.3)
1050 */
1051 Failed:
1052 if (pipe)
1053 usb_stor_clear_halt(us, pipe);
1054 return USB_STOR_TRANSPORT_FAILED;
1055 }
1056 EXPORT_SYMBOL_GPL(usb_stor_CB_transport);
1057
1058 /*
1059 * Bulk only transport
1060 */
1061
1062 /* Determine what the maximum LUN supported is */
1063 int usb_stor_Bulk_max_lun(struct us_data *us)
1064 {
1065 int result;
1066
1067 /* issue the command */
1068 us->iobuf[0] = 0;
1069 result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
1070 US_BULK_GET_MAX_LUN,
1071 USB_DIR_IN | USB_TYPE_CLASS |
1072 USB_RECIP_INTERFACE,
1073 0, us->ifnum, us->iobuf, 1, 10*HZ);
1074
1075 usb_stor_dbg(us, "GetMaxLUN command result is %d, data is %d\n",
1076 result, us->iobuf[0]);
1077
1078 /*
1079 * If we have a successful request, return the result if valid. The
1080 * CBW LUN field is 4 bits wide, so the value reported by the device
1081 * should fit into that.
1082 */
1083 if (result > 0) {
1084 if (us->iobuf[0] < 16) {
1085 return us->iobuf[0];
1086 } else {
1087 dev_info(&us->pusb_intf->dev,
1088 "Max LUN %d is not valid, using 0 instead",
1089 us->iobuf[0]);
1090 }
1091 }
1092
1093 /*
1094 * Some devices don't like GetMaxLUN. They may STALL the control
1095 * pipe, they may return a zero-length result, they may do nothing at
1096 * all and timeout, or they may fail in even more bizarrely creative
1097 * ways. In these cases the best approach is to use the default
1098 * value: only one LUN.
1099 */
1100 return 0;
1101 }
1102
1103 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
1104 {
1105 struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
1106 struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
1107 unsigned int transfer_length = scsi_bufflen(srb);
1108 unsigned int residue;
1109 int result;
1110 int fake_sense = 0;
1111 unsigned int cswlen;
1112 unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
1113
1114 /* Take care of BULK32 devices; set extra byte to 0 */
1115 if (unlikely(us->fflags & US_FL_BULK32)) {
1116 cbwlen = 32;
1117 us->iobuf[31] = 0;
1118 }
1119
1120 /* set up the command wrapper */
1121 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
1122 bcb->DataTransferLength = cpu_to_le32(transfer_length);
1123 bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ?
1124 US_BULK_FLAG_IN : 0;
1125 bcb->Tag = ++us->tag;
1126 bcb->Lun = srb->device->lun;
1127 if (us->fflags & US_FL_SCM_MULT_TARG)
1128 bcb->Lun |= srb->device->id << 4;
1129 bcb->Length = srb->cmd_len;
1130
1131 /* copy the command payload */
1132 memset(bcb->CDB, 0, sizeof(bcb->CDB));
1133 memcpy(bcb->CDB, srb->cmnd, bcb->Length);
1134
1135 /* send it to out endpoint */
1136 usb_stor_dbg(us, "Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
1137 le32_to_cpu(bcb->Signature), bcb->Tag,
1138 le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
1139 (bcb->Lun >> 4), (bcb->Lun & 0x0F),
1140 bcb->Length);
1141 result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
1142 bcb, cbwlen, NULL);
1143 usb_stor_dbg(us, "Bulk command transfer result=%d\n", result);
1144 if (result != USB_STOR_XFER_GOOD)
1145 return USB_STOR_TRANSPORT_ERROR;
1146
1147 /* DATA STAGE */
1148 /* send/receive data payload, if there is any */
1149
1150 /*
1151 * Some USB-IDE converter chips need a 100us delay between the
1152 * command phase and the data phase. Some devices need a little
1153 * more than that, probably because of clock rate inaccuracies.
1154 */
1155 if (unlikely(us->fflags & US_FL_GO_SLOW))
1156 usleep_range(125, 150);
1157
1158 if (transfer_length) {
1159 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
1160 us->recv_bulk_pipe : us->send_bulk_pipe;
1161 result = usb_stor_bulk_srb(us, pipe, srb);
1162 usb_stor_dbg(us, "Bulk data transfer result 0x%x\n", result);
1163 if (result == USB_STOR_XFER_ERROR)
1164 return USB_STOR_TRANSPORT_ERROR;
1165
1166 /*
1167 * If the device tried to send back more data than the
1168 * amount requested, the spec requires us to transfer
1169 * the CSW anyway. Since there's no point retrying the
1170 * the command, we'll return fake sense data indicating
1171 * Illegal Request, Invalid Field in CDB.
1172 */
1173 if (result == USB_STOR_XFER_LONG)
1174 fake_sense = 1;
1175
1176 /*
1177 * Sometimes a device will mistakenly skip the data phase
1178 * and go directly to the status phase without sending a
1179 * zero-length packet. If we get a 13-byte response here,
1180 * check whether it really is a CSW.
1181 */
1182 if (result == USB_STOR_XFER_SHORT &&
1183 srb->sc_data_direction == DMA_FROM_DEVICE &&
1184 transfer_length - scsi_get_resid(srb) ==
1185 US_BULK_CS_WRAP_LEN) {
1186 struct scatterlist *sg = NULL;
1187 unsigned int offset = 0;
1188
1189 if (usb_stor_access_xfer_buf((unsigned char *) bcs,
1190 US_BULK_CS_WRAP_LEN, srb, &sg,
1191 &offset, FROM_XFER_BUF) ==
1192 US_BULK_CS_WRAP_LEN &&
1193 bcs->Signature ==
1194 cpu_to_le32(US_BULK_CS_SIGN)) {
1195 usb_stor_dbg(us, "Device skipped data phase\n");
1196 scsi_set_resid(srb, transfer_length);
1197 goto skipped_data_phase;
1198 }
1199 }
1200 }
1201
1202 /*
1203 * See flow chart on pg 15 of the Bulk Only Transport spec for
1204 * an explanation of how this code works.
1205 */
1206
1207 /* get CSW for device status */
1208 usb_stor_dbg(us, "Attempting to get CSW...\n");
1209 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1210 bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1211
1212 /*
1213 * Some broken devices add unnecessary zero-length packets to the
1214 * end of their data transfers. Such packets show up as 0-length
1215 * CSWs. If we encounter such a thing, try to read the CSW again.
1216 */
1217 if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
1218 usb_stor_dbg(us, "Received 0-length CSW; retrying...\n");
1219 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1220 bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1221 }
1222
1223 /* did the attempt to read the CSW fail? */
1224 if (result == USB_STOR_XFER_STALLED) {
1225
1226 /* get the status again */
1227 usb_stor_dbg(us, "Attempting to get CSW (2nd try)...\n");
1228 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1229 bcs, US_BULK_CS_WRAP_LEN, NULL);
1230 }
1231
1232 /* if we still have a failure at this point, we're in trouble */
1233 usb_stor_dbg(us, "Bulk status result = %d\n", result);
1234 if (result != USB_STOR_XFER_GOOD)
1235 return USB_STOR_TRANSPORT_ERROR;
1236
1237 skipped_data_phase:
1238 /* check bulk status */
1239 residue = le32_to_cpu(bcs->Residue);
1240 usb_stor_dbg(us, "Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
1241 le32_to_cpu(bcs->Signature), bcs->Tag,
1242 residue, bcs->Status);
1243 if (!(bcs->Tag == us->tag || (us->fflags & US_FL_BULK_IGNORE_TAG)) ||
1244 bcs->Status > US_BULK_STAT_PHASE) {
1245 usb_stor_dbg(us, "Bulk logical error\n");
1246 return USB_STOR_TRANSPORT_ERROR;
1247 }
1248
1249 /*
1250 * Some broken devices report odd signatures, so we do not check them
1251 * for validity against the spec. We store the first one we see,
1252 * and check subsequent transfers for validity against this signature.
1253 */
1254 if (!us->bcs_signature) {
1255 us->bcs_signature = bcs->Signature;
1256 if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
1257 usb_stor_dbg(us, "Learnt BCS signature 0x%08X\n",
1258 le32_to_cpu(us->bcs_signature));
1259 } else if (bcs->Signature != us->bcs_signature) {
1260 usb_stor_dbg(us, "Signature mismatch: got %08X, expecting %08X\n",
1261 le32_to_cpu(bcs->Signature),
1262 le32_to_cpu(us->bcs_signature));
1263 return USB_STOR_TRANSPORT_ERROR;
1264 }
1265
1266 /*
1267 * try to compute the actual residue, based on how much data
1268 * was really transferred and what the device tells us
1269 */
1270 if (residue && !(us->fflags & US_FL_IGNORE_RESIDUE)) {
1271
1272 /*
1273 * Heuristically detect devices that generate bogus residues
1274 * by seeing what happens with INQUIRY and READ CAPACITY
1275 * commands.
1276 */
1277 if (bcs->Status == US_BULK_STAT_OK &&
1278 scsi_get_resid(srb) == 0 &&
1279 ((srb->cmnd[0] == INQUIRY &&
1280 transfer_length == 36) ||
1281 (srb->cmnd[0] == READ_CAPACITY &&
1282 transfer_length == 8))) {
1283 us->fflags |= US_FL_IGNORE_RESIDUE;
1284
1285 } else {
1286 residue = min(residue, transfer_length);
1287 scsi_set_resid(srb, max(scsi_get_resid(srb),
1288 (int) residue));
1289 }
1290 }
1291
1292 /* based on the status code, we report good or bad */
1293 switch (bcs->Status) {
1294 case US_BULK_STAT_OK:
1295 /* device babbled -- return fake sense data */
1296 if (fake_sense) {
1297 memcpy(srb->sense_buffer,
1298 usb_stor_sense_invalidCDB,
1299 sizeof(usb_stor_sense_invalidCDB));
1300 return USB_STOR_TRANSPORT_NO_SENSE;
1301 }
1302
1303 /* command good -- note that data could be short */
1304 return USB_STOR_TRANSPORT_GOOD;
1305
1306 case US_BULK_STAT_FAIL:
1307 /* command failed */
1308 return USB_STOR_TRANSPORT_FAILED;
1309
1310 case US_BULK_STAT_PHASE:
1311 /*
1312 * phase error -- note that a transport reset will be
1313 * invoked by the invoke_transport() function
1314 */
1315 return USB_STOR_TRANSPORT_ERROR;
1316 }
1317
1318 /* we should never get here, but if we do, we're in trouble */
1319 return USB_STOR_TRANSPORT_ERROR;
1320 }
1321 EXPORT_SYMBOL_GPL(usb_stor_Bulk_transport);
1322
1323 /***********************************************************************
1324 * Reset routines
1325 ***********************************************************************/
1326
1327 /*
1328 * This is the common part of the device reset code.
1329 *
1330 * It's handy that every transport mechanism uses the control endpoint for
1331 * resets.
1332 *
1333 * Basically, we send a reset with a 5-second timeout, so we don't get
1334 * jammed attempting to do the reset.
1335 */
1336 static int usb_stor_reset_common(struct us_data *us,
1337 u8 request, u8 requesttype,
1338 u16 value, u16 index, void *data, u16 size)
1339 {
1340 int result;
1341 int result2;
1342
1343 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1344 usb_stor_dbg(us, "No reset during disconnect\n");
1345 return -EIO;
1346 }
1347
1348 result = usb_stor_control_msg(us, us->send_ctrl_pipe,
1349 request, requesttype, value, index, data, size,
1350 5*HZ);
1351 if (result < 0) {
1352 usb_stor_dbg(us, "Soft reset failed: %d\n", result);
1353 return result;
1354 }
1355
1356 /*
1357 * Give the device some time to recover from the reset,
1358 * but don't delay disconnect processing.
1359 */
1360 wait_event_interruptible_timeout(us->delay_wait,
1361 test_bit(US_FLIDX_DISCONNECTING, &us->dflags),
1362 HZ*6);
1363 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1364 usb_stor_dbg(us, "Reset interrupted by disconnect\n");
1365 return -EIO;
1366 }
1367
1368 usb_stor_dbg(us, "Soft reset: clearing bulk-in endpoint halt\n");
1369 result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
1370
1371 usb_stor_dbg(us, "Soft reset: clearing bulk-out endpoint halt\n");
1372 result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
1373
1374 /* return a result code based on the result of the clear-halts */
1375 if (result >= 0)
1376 result = result2;
1377 if (result < 0)
1378 usb_stor_dbg(us, "Soft reset failed\n");
1379 else
1380 usb_stor_dbg(us, "Soft reset done\n");
1381 return result;
1382 }
1383
1384 /* This issues a CB[I] Reset to the device in question */
1385 #define CB_RESET_CMD_SIZE 12
1386
1387 int usb_stor_CB_reset(struct us_data *us)
1388 {
1389 memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
1390 us->iobuf[0] = SEND_DIAGNOSTIC;
1391 us->iobuf[1] = 4;
1392 return usb_stor_reset_common(us, US_CBI_ADSC,
1393 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1394 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
1395 }
1396 EXPORT_SYMBOL_GPL(usb_stor_CB_reset);
1397
1398 /*
1399 * This issues a Bulk-only Reset to the device in question, including
1400 * clearing the subsequent endpoint halts that may occur.
1401 */
1402 int usb_stor_Bulk_reset(struct us_data *us)
1403 {
1404 return usb_stor_reset_common(us, US_BULK_RESET_REQUEST,
1405 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1406 0, us->ifnum, NULL, 0);
1407 }
1408 EXPORT_SYMBOL_GPL(usb_stor_Bulk_reset);
1409
1410 /*
1411 * Issue a USB port reset to the device. The caller must not hold
1412 * us->dev_mutex.
1413 */
1414 int usb_stor_port_reset(struct us_data *us)
1415 {
1416 int result;
1417
1418 /*for these devices we must use the class specific method */
1419 if (us->pusb_dev->quirks & USB_QUIRK_RESET)
1420 return -EPERM;
1421
1422 result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
1423 if (result < 0)
1424 usb_stor_dbg(us, "unable to lock device for reset: %d\n",
1425 result);
1426 else {
1427 /* Were we disconnected while waiting for the lock? */
1428 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1429 result = -EIO;
1430 usb_stor_dbg(us, "No reset during disconnect\n");
1431 } else {
1432 result = usb_reset_device(us->pusb_dev);
1433 usb_stor_dbg(us, "usb_reset_device returns %d\n",
1434 result);
1435 }
1436 usb_unlock_device(us->pusb_dev);
1437 }
1438 return result;
1439 }