Full support for Ginger Console
[linux-ginger.git] / drivers / usb / storage / transport.c
blob589f6b4404f0b1550718c66353ec4c807c0a46ac
1 /* Driver for USB Mass Storage compliant devices
3 * Current development and maintenance by:
4 * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
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>
11 * Initial work by:
12 * (c) 1999 Michael Gee (michael@linuxspecific.com)
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.
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.
25 * Also, for certain devices, the interrupt endpoint is used to convey
26 * status of a command.
28 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
29 * information about this driver.
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.
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.
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.
46 #include <linux/sched.h>
47 #include <linux/errno.h>
48 #include <linux/slab.h>
50 #include <scsi/scsi.h>
51 #include <scsi/scsi_eh.h>
52 #include <scsi/scsi_device.h>
54 #include "usb.h"
55 #include "transport.h"
56 #include "protocol.h"
57 #include "scsiglue.h"
58 #include "debug.h"
60 #include <linux/blkdev.h>
61 #include "../../scsi/sd.h"
64 /***********************************************************************
65 * Data transfer routines
66 ***********************************************************************/
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.)
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.
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.
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.
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().
109 /* This is the completion handler which will wake us up when an URB
110 * completes.
112 static void usb_stor_blocking_completion(struct urb *urb)
114 struct completion *urb_done_ptr = urb->context;
116 complete(urb_done_ptr);
119 /* This is the common part of the URB message submission code
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.
125 static int usb_stor_msg_common(struct us_data *us, int timeout)
127 struct completion urb_done;
128 long timeleft;
129 int status;
131 /* don't submit URBs during abort processing */
132 if (test_bit(US_FLIDX_ABORTING, &us->dflags))
133 return -EIO;
135 /* set up data structures for the wakeup system */
136 init_completion(&urb_done);
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;
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;
154 /* submit the URB */
155 status = usb_submit_urb(us->current_urb, GFP_NOIO);
156 if (status) {
157 /* something went wrong */
158 return status;
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);
165 /* did an abort occur during the submission? */
166 if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
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);
175 /* wait for the completion of the URB */
176 timeleft = wait_for_completion_interruptible_timeout(
177 &urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT);
179 clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags);
181 if (timeleft <= 0) {
182 US_DEBUGP("%s -- cancelling URB\n",
183 timeleft == 0 ? "Timeout" : "Signal");
184 usb_kill_urb(us->current_urb);
187 /* return the URB status */
188 return us->current_urb->status;
192 * Transfer one control message, with timeouts, and allowing early
193 * termination. Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx.
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)
199 int status;
201 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
202 __func__, request, requesttype,
203 value, index, size);
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);
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);
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;
223 EXPORT_SYMBOL_GPL(usb_stor_control_msg);
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.
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.
234 * Since many vendors in this space limit their testing to interoperability
235 * with these two OSes, specification violations like this one are common.
237 int usb_stor_clear_halt(struct us_data *us, unsigned int pipe)
239 int result;
240 int endp = usb_pipeendpoint(pipe);
242 if (usb_pipein (pipe))
243 endp |= USB_DIR_IN;
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);
250 if (result >= 0)
251 usb_reset_endpoint(us->pusb_dev, endp);
253 US_DEBUGP("%s: result = %d\n", __func__, result);
254 return result;
256 EXPORT_SYMBOL_GPL(usb_stor_clear_halt);
260 * Interpret the results of a URB transfer
262 * This function prints appropriate debugging messages, clears halts on
263 * non-control endpoints, and translates the status to the corresponding
264 * USB_STOR_XFER_xxx return code.
266 static int interpret_urb_result(struct us_data *us, unsigned int pipe,
267 unsigned int length, int result, unsigned int partial)
269 US_DEBUGP("Status code %d; transferred %u/%u\n",
270 result, partial, length);
271 switch (result) {
273 /* no error code; did we send all the data? */
274 case 0:
275 if (partial != length) {
276 US_DEBUGP("-- short transfer\n");
277 return USB_STOR_XFER_SHORT;
280 US_DEBUGP("-- transfer complete\n");
281 return USB_STOR_XFER_GOOD;
283 /* stalled */
284 case -EPIPE:
285 /* for control endpoints, (used by CB[I]) a stall indicates
286 * a failed command */
287 if (usb_pipecontrol(pipe)) {
288 US_DEBUGP("-- stall on control pipe\n");
289 return USB_STOR_XFER_STALLED;
292 /* for other sorts of endpoint, clear the stall */
293 US_DEBUGP("clearing endpoint halt for pipe 0x%x\n", pipe);
294 if (usb_stor_clear_halt(us, pipe) < 0)
295 return USB_STOR_XFER_ERROR;
296 return USB_STOR_XFER_STALLED;
298 /* babble - the device tried to send more than we wanted to read */
299 case -EOVERFLOW:
300 US_DEBUGP("-- babble\n");
301 return USB_STOR_XFER_LONG;
303 /* the transfer was cancelled by abort, disconnect, or timeout */
304 case -ECONNRESET:
305 US_DEBUGP("-- transfer cancelled\n");
306 return USB_STOR_XFER_ERROR;
308 /* short scatter-gather read transfer */
309 case -EREMOTEIO:
310 US_DEBUGP("-- short read transfer\n");
311 return USB_STOR_XFER_SHORT;
313 /* abort or disconnect in progress */
314 case -EIO:
315 US_DEBUGP("-- abort or disconnect in progress\n");
316 return USB_STOR_XFER_ERROR;
318 /* the catch-all error case */
319 default:
320 US_DEBUGP("-- unknown error\n");
321 return USB_STOR_XFER_ERROR;
326 * Transfer one control message, without timeouts, but allowing early
327 * termination. Return codes are USB_STOR_XFER_xxx.
329 int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe,
330 u8 request, u8 requesttype, u16 value, u16 index,
331 void *data, u16 size)
333 int result;
335 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n",
336 __func__, request, requesttype,
337 value, index, size);
339 /* fill in the devrequest structure */
340 us->cr->bRequestType = requesttype;
341 us->cr->bRequest = request;
342 us->cr->wValue = cpu_to_le16(value);
343 us->cr->wIndex = cpu_to_le16(index);
344 us->cr->wLength = cpu_to_le16(size);
346 /* fill and submit the URB */
347 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe,
348 (unsigned char*) us->cr, data, size,
349 usb_stor_blocking_completion, NULL);
350 result = usb_stor_msg_common(us, 0);
352 return interpret_urb_result(us, pipe, size, result,
353 us->current_urb->actual_length);
355 EXPORT_SYMBOL_GPL(usb_stor_ctrl_transfer);
358 * Receive one interrupt buffer, without timeouts, but allowing early
359 * termination. Return codes are USB_STOR_XFER_xxx.
361 * This routine always uses us->recv_intr_pipe as the pipe and
362 * us->ep_bInterval as the interrupt interval.
364 static int usb_stor_intr_transfer(struct us_data *us, void *buf,
365 unsigned int length)
367 int result;
368 unsigned int pipe = us->recv_intr_pipe;
369 unsigned int maxp;
371 US_DEBUGP("%s: xfer %u bytes\n", __func__, length);
373 /* calculate the max packet size */
374 maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe));
375 if (maxp > length)
376 maxp = length;
378 /* fill and submit the URB */
379 usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf,
380 maxp, usb_stor_blocking_completion, NULL,
381 us->ep_bInterval);
382 result = usb_stor_msg_common(us, 0);
384 return interpret_urb_result(us, pipe, length, result,
385 us->current_urb->actual_length);
389 * Transfer one buffer via bulk pipe, without timeouts, but allowing early
390 * termination. Return codes are USB_STOR_XFER_xxx. If the bulk pipe
391 * stalls during the transfer, the halt is automatically cleared.
393 int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe,
394 void *buf, unsigned int length, unsigned int *act_len)
396 int result;
398 US_DEBUGP("%s: xfer %u bytes\n", __func__, length);
400 /* fill and submit the URB */
401 usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length,
402 usb_stor_blocking_completion, NULL);
403 result = usb_stor_msg_common(us, 0);
405 /* store the actual length of the data transferred */
406 if (act_len)
407 *act_len = us->current_urb->actual_length;
408 return interpret_urb_result(us, pipe, length, result,
409 us->current_urb->actual_length);
411 EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_buf);
414 * Transfer a scatter-gather list via bulk transfer
416 * This function does basically the same thing as usb_stor_bulk_transfer_buf()
417 * above, but it uses the usbcore scatter-gather library.
419 static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe,
420 struct scatterlist *sg, int num_sg, unsigned int length,
421 unsigned int *act_len)
423 int result;
425 /* don't submit s-g requests during abort processing */
426 if (test_bit(US_FLIDX_ABORTING, &us->dflags))
427 return USB_STOR_XFER_ERROR;
429 /* initialize the scatter-gather request block */
430 US_DEBUGP("%s: xfer %u bytes, %d entries\n", __func__,
431 length, num_sg);
432 result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0,
433 sg, num_sg, length, GFP_NOIO);
434 if (result) {
435 US_DEBUGP("usb_sg_init returned %d\n", result);
436 return USB_STOR_XFER_ERROR;
439 /* since the block has been initialized successfully, it's now
440 * okay to cancel it */
441 set_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
443 /* did an abort occur during the submission? */
444 if (test_bit(US_FLIDX_ABORTING, &us->dflags)) {
446 /* cancel the request, if it hasn't been cancelled already */
447 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
448 US_DEBUGP("-- cancelling sg request\n");
449 usb_sg_cancel(&us->current_sg);
453 /* wait for the completion of the transfer */
454 usb_sg_wait(&us->current_sg);
455 clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags);
457 result = us->current_sg.status;
458 if (act_len)
459 *act_len = us->current_sg.bytes;
460 return interpret_urb_result(us, pipe, length, result,
461 us->current_sg.bytes);
465 * Common used function. Transfer a complete command
466 * via usb_stor_bulk_transfer_sglist() above. Set cmnd resid
468 int usb_stor_bulk_srb(struct us_data* us, unsigned int pipe,
469 struct scsi_cmnd* srb)
471 unsigned int partial;
472 int result = usb_stor_bulk_transfer_sglist(us, pipe, scsi_sglist(srb),
473 scsi_sg_count(srb), scsi_bufflen(srb),
474 &partial);
476 scsi_set_resid(srb, scsi_bufflen(srb) - partial);
477 return result;
479 EXPORT_SYMBOL_GPL(usb_stor_bulk_srb);
482 * Transfer an entire SCSI command's worth of data payload over the bulk
483 * pipe.
485 * Note that this uses usb_stor_bulk_transfer_buf() and
486 * usb_stor_bulk_transfer_sglist() to achieve its goals --
487 * this function simply determines whether we're going to use
488 * scatter-gather or not, and acts appropriately.
490 int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe,
491 void *buf, unsigned int length_left, int use_sg, int *residual)
493 int result;
494 unsigned int partial;
496 /* are we scatter-gathering? */
497 if (use_sg) {
498 /* use the usb core scatter-gather primitives */
499 result = usb_stor_bulk_transfer_sglist(us, pipe,
500 (struct scatterlist *) buf, use_sg,
501 length_left, &partial);
502 length_left -= partial;
503 } else {
504 /* no scatter-gather, just make the request */
505 result = usb_stor_bulk_transfer_buf(us, pipe, buf,
506 length_left, &partial);
507 length_left -= partial;
510 /* store the residual and return the error code */
511 if (residual)
512 *residual = length_left;
513 return result;
515 EXPORT_SYMBOL_GPL(usb_stor_bulk_transfer_sg);
517 /***********************************************************************
518 * Transport routines
519 ***********************************************************************/
521 /* There are so many devices that report the capacity incorrectly,
522 * this routine was written to counteract some of the resulting
523 * problems.
525 static void last_sector_hacks(struct us_data *us, struct scsi_cmnd *srb)
527 struct gendisk *disk;
528 struct scsi_disk *sdkp;
529 u32 sector;
531 /* To Report "Medium Error: Record Not Found */
532 static unsigned char record_not_found[18] = {
533 [0] = 0x70, /* current error */
534 [2] = MEDIUM_ERROR, /* = 0x03 */
535 [7] = 0x0a, /* additional length */
536 [12] = 0x14 /* Record Not Found */
539 /* If last-sector problems can't occur, whether because the
540 * capacity was already decremented or because the device is
541 * known to report the correct capacity, then we don't need
542 * to do anything.
544 if (!us->use_last_sector_hacks)
545 return;
547 /* Was this command a READ(10) or a WRITE(10)? */
548 if (srb->cmnd[0] != READ_10 && srb->cmnd[0] != WRITE_10)
549 goto done;
551 /* Did this command access the last sector? */
552 sector = (srb->cmnd[2] << 24) | (srb->cmnd[3] << 16) |
553 (srb->cmnd[4] << 8) | (srb->cmnd[5]);
554 disk = srb->request->rq_disk;
555 if (!disk)
556 goto done;
557 sdkp = scsi_disk(disk);
558 if (!sdkp)
559 goto done;
560 if (sector + 1 != sdkp->capacity)
561 goto done;
563 if (srb->result == SAM_STAT_GOOD && scsi_get_resid(srb) == 0) {
565 /* The command succeeded. We know this device doesn't
566 * have the last-sector bug, so stop checking it.
568 us->use_last_sector_hacks = 0;
570 } else {
571 /* The command failed. Allow up to 3 retries in case this
572 * is some normal sort of failure. After that, assume the
573 * capacity is wrong and we're trying to access the sector
574 * beyond the end. Replace the result code and sense data
575 * with values that will cause the SCSI core to fail the
576 * command immediately, instead of going into an infinite
577 * (or even just a very long) retry loop.
579 if (++us->last_sector_retries < 3)
580 return;
581 srb->result = SAM_STAT_CHECK_CONDITION;
582 memcpy(srb->sense_buffer, record_not_found,
583 sizeof(record_not_found));
586 done:
587 /* Don't reset the retry counter for TEST UNIT READY commands,
588 * because they get issued after device resets which might be
589 * caused by a failed last-sector access.
591 if (srb->cmnd[0] != TEST_UNIT_READY)
592 us->last_sector_retries = 0;
595 /* Invoke the transport and basic error-handling/recovery methods
597 * This is used by the protocol layers to actually send the message to
598 * the device and receive the response.
600 void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
602 int need_auto_sense;
603 int result;
605 /* send the command to the transport layer */
606 scsi_set_resid(srb, 0);
607 result = us->transport(srb, us);
609 /* if the command gets aborted by the higher layers, we need to
610 * short-circuit all other processing
612 if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
613 US_DEBUGP("-- command was aborted\n");
614 srb->result = DID_ABORT << 16;
615 goto Handle_Errors;
618 /* if there is a transport error, reset and don't auto-sense */
619 if (result == USB_STOR_TRANSPORT_ERROR) {
620 US_DEBUGP("-- transport indicates error, resetting\n");
621 srb->result = DID_ERROR << 16;
622 goto Handle_Errors;
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;
632 srb->result = SAM_STAT_GOOD;
634 /* Determine if we need to auto-sense
636 * I normally don't use a flag like this, but it's almost impossible
637 * to understand what's going on here if I don't.
639 need_auto_sense = 0;
642 * If we're running the CB transport, which is incapable
643 * of determining status on its own, we will auto-sense
644 * unless the operation involved a data-in transfer. Devices
645 * can signal most data-in errors by stalling the bulk-in pipe.
647 if ((us->protocol == US_PR_CB || us->protocol == US_PR_DPCM_USB) &&
648 srb->sc_data_direction != DMA_FROM_DEVICE) {
649 US_DEBUGP("-- CB transport device requiring auto-sense\n");
650 need_auto_sense = 1;
654 * If we have a failure, we're going to do a REQUEST_SENSE
655 * automatically. Note that we differentiate between a command
656 * "failure" and an "error" in the transport mechanism.
658 if (result == USB_STOR_TRANSPORT_FAILED) {
659 US_DEBUGP("-- transport indicates command failure\n");
660 need_auto_sense = 1;
664 * Determine if this device is SAT by seeing if the
665 * command executed successfully. Otherwise we'll have
666 * to wait for at least one CHECK_CONDITION to determine
667 * SANE_SENSE support
669 if ((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
670 result == USB_STOR_TRANSPORT_GOOD &&
671 !(us->fflags & US_FL_SANE_SENSE) &&
672 !(srb->cmnd[2] & 0x20)) {
673 US_DEBUGP("-- SAT supported, increasing auto-sense\n");
674 us->fflags |= US_FL_SANE_SENSE;
678 * A short transfer on a command where we don't expect it
679 * is unusual, but it doesn't mean we need to auto-sense.
681 if ((scsi_get_resid(srb) > 0) &&
682 !((srb->cmnd[0] == REQUEST_SENSE) ||
683 (srb->cmnd[0] == INQUIRY) ||
684 (srb->cmnd[0] == MODE_SENSE) ||
685 (srb->cmnd[0] == LOG_SENSE) ||
686 (srb->cmnd[0] == MODE_SENSE_10))) {
687 US_DEBUGP("-- unexpectedly short transfer\n");
690 /* Now, if we need to do the auto-sense, let's do it */
691 if (need_auto_sense) {
692 int temp_result;
693 struct scsi_eh_save ses;
694 int sense_size = US_SENSE_SIZE;
696 /* device supports and needs bigger sense buffer */
697 if (us->fflags & US_FL_SANE_SENSE)
698 sense_size = ~0;
699 Retry_Sense:
700 US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
702 scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sense_size);
704 /* FIXME: we must do the protocol translation here */
705 if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI ||
706 us->subclass == US_SC_CYP_ATACB)
707 srb->cmd_len = 6;
708 else
709 srb->cmd_len = 12;
711 /* issue the auto-sense command */
712 scsi_set_resid(srb, 0);
713 temp_result = us->transport(us->srb, us);
715 /* let's clean up right away */
716 scsi_eh_restore_cmnd(srb, &ses);
718 if (test_bit(US_FLIDX_TIMED_OUT, &us->dflags)) {
719 US_DEBUGP("-- auto-sense aborted\n");
720 srb->result = DID_ABORT << 16;
721 goto Handle_Errors;
724 /* Some devices claim to support larger sense but fail when
725 * trying to request it. When a transport failure happens
726 * using US_FS_SANE_SENSE, we always retry with a standard
727 * (small) sense request. This fixes some USB GSM modems
729 if (temp_result == USB_STOR_TRANSPORT_FAILED &&
730 (us->fflags & US_FL_SANE_SENSE) &&
731 sense_size != US_SENSE_SIZE) {
732 US_DEBUGP("-- auto-sense failure, retry small sense\n");
733 sense_size = US_SENSE_SIZE;
734 goto Retry_Sense;
737 /* Other failures */
738 if (temp_result != USB_STOR_TRANSPORT_GOOD) {
739 US_DEBUGP("-- auto-sense failure\n");
741 /* we skip the reset if this happens to be a
742 * multi-target device, since failure of an
743 * auto-sense is perfectly valid
745 srb->result = DID_ERROR << 16;
746 if (!(us->fflags & US_FL_SCM_MULT_TARG))
747 goto Handle_Errors;
748 return;
751 /* If the sense data returned is larger than 18-bytes then we
752 * assume this device supports requesting more in the future.
753 * The response code must be 70h through 73h inclusive.
755 if (srb->sense_buffer[7] > (US_SENSE_SIZE - 8) &&
756 !(us->fflags & US_FL_SANE_SENSE) &&
757 (srb->sense_buffer[0] & 0x7C) == 0x70) {
758 US_DEBUGP("-- SANE_SENSE support enabled\n");
759 us->fflags |= US_FL_SANE_SENSE;
761 /* Indicate to the user that we truncated their sense
762 * because we didn't know it supported larger sense.
764 US_DEBUGP("-- Sense data truncated to %i from %i\n",
765 US_SENSE_SIZE,
766 srb->sense_buffer[7] + 8);
767 srb->sense_buffer[7] = (US_SENSE_SIZE - 8);
770 US_DEBUGP("-- Result from auto-sense is %d\n", temp_result);
771 US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
772 srb->sense_buffer[0],
773 srb->sense_buffer[2] & 0xf,
774 srb->sense_buffer[12],
775 srb->sense_buffer[13]);
776 #ifdef CONFIG_USB_STORAGE_DEBUG
777 usb_stor_show_sense(
778 srb->sense_buffer[2] & 0xf,
779 srb->sense_buffer[12],
780 srb->sense_buffer[13]);
781 #endif
783 /* set the result so the higher layers expect this data */
784 srb->result = SAM_STAT_CHECK_CONDITION;
786 /* We often get empty sense data. This could indicate that
787 * everything worked or that there was an unspecified
788 * problem. We have to decide which.
790 if ( /* Filemark 0, ignore EOM, ILI 0, no sense */
791 (srb->sense_buffer[2] & 0xaf) == 0 &&
792 /* No ASC or ASCQ */
793 srb->sense_buffer[12] == 0 &&
794 srb->sense_buffer[13] == 0) {
796 /* If things are really okay, then let's show that.
797 * Zero out the sense buffer so the higher layers
798 * won't realize we did an unsolicited auto-sense.
800 if (result == USB_STOR_TRANSPORT_GOOD) {
801 srb->result = SAM_STAT_GOOD;
802 srb->sense_buffer[0] = 0x0;
804 /* If there was a problem, report an unspecified
805 * hardware error to prevent the higher layers from
806 * entering an infinite retry loop.
808 } else {
809 srb->result = DID_ERROR << 16;
810 srb->sense_buffer[2] = HARDWARE_ERROR;
815 /* Did we transfer less than the minimum amount required? */
816 if ((srb->result == SAM_STAT_GOOD || srb->sense_buffer[2] == 0) &&
817 scsi_bufflen(srb) - scsi_get_resid(srb) < srb->underflow)
818 srb->result = DID_ERROR << 16;
820 last_sector_hacks(us, srb);
821 return;
823 /* Error and abort processing: try to resynchronize with the device
824 * by issuing a port reset. If that fails, try a class-specific
825 * device reset. */
826 Handle_Errors:
828 /* Set the RESETTING bit, and clear the ABORTING bit so that
829 * the reset may proceed. */
830 scsi_lock(us_to_host(us));
831 set_bit(US_FLIDX_RESETTING, &us->dflags);
832 clear_bit(US_FLIDX_ABORTING, &us->dflags);
833 scsi_unlock(us_to_host(us));
835 /* We must release the device lock because the pre_reset routine
836 * will want to acquire it. */
837 mutex_unlock(&us->dev_mutex);
838 result = usb_stor_port_reset(us);
839 mutex_lock(&us->dev_mutex);
841 if (result < 0) {
842 scsi_lock(us_to_host(us));
843 usb_stor_report_device_reset(us);
844 scsi_unlock(us_to_host(us));
845 us->transport_reset(us);
847 clear_bit(US_FLIDX_RESETTING, &us->dflags);
848 last_sector_hacks(us, srb);
851 /* Stop the current URB transfer */
852 void usb_stor_stop_transport(struct us_data *us)
854 US_DEBUGP("%s called\n", __func__);
856 /* If the state machine is blocked waiting for an URB,
857 * let's wake it up. The test_and_clear_bit() call
858 * guarantees that if a URB has just been submitted,
859 * it won't be cancelled more than once. */
860 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->dflags)) {
861 US_DEBUGP("-- cancelling URB\n");
862 usb_unlink_urb(us->current_urb);
865 /* If we are waiting for a scatter-gather operation, cancel it. */
866 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->dflags)) {
867 US_DEBUGP("-- cancelling sg request\n");
868 usb_sg_cancel(&us->current_sg);
873 * Control/Bulk and Control/Bulk/Interrupt transport
876 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us)
878 unsigned int transfer_length = scsi_bufflen(srb);
879 unsigned int pipe = 0;
880 int result;
882 /* COMMAND STAGE */
883 /* let's send the command via the control pipe */
884 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe,
885 US_CBI_ADSC,
886 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0,
887 us->ifnum, srb->cmnd, srb->cmd_len);
889 /* check the return code for the command */
890 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result);
892 /* if we stalled the command, it means command failed */
893 if (result == USB_STOR_XFER_STALLED) {
894 return USB_STOR_TRANSPORT_FAILED;
897 /* Uh oh... serious problem here */
898 if (result != USB_STOR_XFER_GOOD) {
899 return USB_STOR_TRANSPORT_ERROR;
902 /* DATA STAGE */
903 /* transfer the data payload for this command, if one exists*/
904 if (transfer_length) {
905 pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
906 us->recv_bulk_pipe : us->send_bulk_pipe;
907 result = usb_stor_bulk_srb(us, pipe, srb);
908 US_DEBUGP("CBI data stage result is 0x%x\n", result);
910 /* if we stalled the data transfer it means command failed */
911 if (result == USB_STOR_XFER_STALLED)
912 return USB_STOR_TRANSPORT_FAILED;
913 if (result > USB_STOR_XFER_STALLED)
914 return USB_STOR_TRANSPORT_ERROR;
917 /* STATUS STAGE */
919 /* NOTE: CB does not have a status stage. Silly, I know. So
920 * we have to catch this at a higher level.
922 if (us->protocol != US_PR_CBI)
923 return USB_STOR_TRANSPORT_GOOD;
925 result = usb_stor_intr_transfer(us, us->iobuf, 2);
926 US_DEBUGP("Got interrupt data (0x%x, 0x%x)\n",
927 us->iobuf[0], us->iobuf[1]);
928 if (result != USB_STOR_XFER_GOOD)
929 return USB_STOR_TRANSPORT_ERROR;
931 /* UFI gives us ASC and ASCQ, like a request sense
933 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI
934 * devices, so we ignore the information for those commands. Note
935 * that this means we could be ignoring a real error on these
936 * commands, but that can't be helped.
938 if (us->subclass == US_SC_UFI) {
939 if (srb->cmnd[0] == REQUEST_SENSE ||
940 srb->cmnd[0] == INQUIRY)
941 return USB_STOR_TRANSPORT_GOOD;
942 if (us->iobuf[0])
943 goto Failed;
944 return USB_STOR_TRANSPORT_GOOD;
947 /* If not UFI, we interpret the data as a result code
948 * The first byte should always be a 0x0.
950 * Some bogus devices don't follow that rule. They stuff the ASC
951 * into the first byte -- so if it's non-zero, call it a failure.
953 if (us->iobuf[0]) {
954 US_DEBUGP("CBI IRQ data showed reserved bType 0x%x\n",
955 us->iobuf[0]);
956 goto Failed;
960 /* The second byte & 0x0F should be 0x0 for good, otherwise error */
961 switch (us->iobuf[1] & 0x0F) {
962 case 0x00:
963 return USB_STOR_TRANSPORT_GOOD;
964 case 0x01:
965 goto Failed;
967 return USB_STOR_TRANSPORT_ERROR;
969 /* the CBI spec requires that the bulk pipe must be cleared
970 * following any data-in/out command failure (section 2.4.3.1.3)
972 Failed:
973 if (pipe)
974 usb_stor_clear_halt(us, pipe);
975 return USB_STOR_TRANSPORT_FAILED;
977 EXPORT_SYMBOL_GPL(usb_stor_CB_transport);
980 * Bulk only transport
983 /* Determine what the maximum LUN supported is */
984 int usb_stor_Bulk_max_lun(struct us_data *us)
986 int result;
988 /* issue the command */
989 us->iobuf[0] = 0;
990 result = usb_stor_control_msg(us, us->recv_ctrl_pipe,
991 US_BULK_GET_MAX_LUN,
992 USB_DIR_IN | USB_TYPE_CLASS |
993 USB_RECIP_INTERFACE,
994 0, us->ifnum, us->iobuf, 1, 10*HZ);
996 US_DEBUGP("GetMaxLUN command result is %d, data is %d\n",
997 result, us->iobuf[0]);
999 /* if we have a successful request, return the result */
1000 if (result > 0)
1001 return us->iobuf[0];
1004 * Some devices don't like GetMaxLUN. They may STALL the control
1005 * pipe, they may return a zero-length result, they may do nothing at
1006 * all and timeout, or they may fail in even more bizarrely creative
1007 * ways. In these cases the best approach is to use the default
1008 * value: only one LUN.
1010 return 0;
1013 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us)
1015 struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf;
1016 struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf;
1017 unsigned int transfer_length = scsi_bufflen(srb);
1018 unsigned int residue;
1019 int result;
1020 int fake_sense = 0;
1021 unsigned int cswlen;
1022 unsigned int cbwlen = US_BULK_CB_WRAP_LEN;
1024 /* Take care of BULK32 devices; set extra byte to 0 */
1025 if (unlikely(us->fflags & US_FL_BULK32)) {
1026 cbwlen = 32;
1027 us->iobuf[31] = 0;
1030 /* set up the command wrapper */
1031 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN);
1032 bcb->DataTransferLength = cpu_to_le32(transfer_length);
1033 bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0;
1034 bcb->Tag = ++us->tag;
1035 bcb->Lun = srb->device->lun;
1036 if (us->fflags & US_FL_SCM_MULT_TARG)
1037 bcb->Lun |= srb->device->id << 4;
1038 bcb->Length = srb->cmd_len;
1040 /* copy the command payload */
1041 memset(bcb->CDB, 0, sizeof(bcb->CDB));
1042 memcpy(bcb->CDB, srb->cmnd, bcb->Length);
1044 /* send it to out endpoint */
1045 US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n",
1046 le32_to_cpu(bcb->Signature), bcb->Tag,
1047 le32_to_cpu(bcb->DataTransferLength), bcb->Flags,
1048 (bcb->Lun >> 4), (bcb->Lun & 0x0F),
1049 bcb->Length);
1050 result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe,
1051 bcb, cbwlen, NULL);
1052 US_DEBUGP("Bulk command transfer result=%d\n", result);
1053 if (result != USB_STOR_XFER_GOOD)
1054 return USB_STOR_TRANSPORT_ERROR;
1056 /* DATA STAGE */
1057 /* send/receive data payload, if there is any */
1059 /* Some USB-IDE converter chips need a 100us delay between the
1060 * command phase and the data phase. Some devices need a little
1061 * more than that, probably because of clock rate inaccuracies. */
1062 if (unlikely(us->fflags & US_FL_GO_SLOW))
1063 udelay(125);
1065 if (transfer_length) {
1066 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ?
1067 us->recv_bulk_pipe : us->send_bulk_pipe;
1068 result = usb_stor_bulk_srb(us, pipe, srb);
1069 US_DEBUGP("Bulk data transfer result 0x%x\n", result);
1070 if (result == USB_STOR_XFER_ERROR)
1071 return USB_STOR_TRANSPORT_ERROR;
1073 /* If the device tried to send back more data than the
1074 * amount requested, the spec requires us to transfer
1075 * the CSW anyway. Since there's no point retrying the
1076 * the command, we'll return fake sense data indicating
1077 * Illegal Request, Invalid Field in CDB.
1079 if (result == USB_STOR_XFER_LONG)
1080 fake_sense = 1;
1083 /* See flow chart on pg 15 of the Bulk Only Transport spec for
1084 * an explanation of how this code works.
1087 /* get CSW for device status */
1088 US_DEBUGP("Attempting to get CSW...\n");
1089 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1090 bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1092 /* Some broken devices add unnecessary zero-length packets to the
1093 * end of their data transfers. Such packets show up as 0-length
1094 * CSWs. If we encounter such a thing, try to read the CSW again.
1096 if (result == USB_STOR_XFER_SHORT && cswlen == 0) {
1097 US_DEBUGP("Received 0-length CSW; retrying...\n");
1098 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1099 bcs, US_BULK_CS_WRAP_LEN, &cswlen);
1102 /* did the attempt to read the CSW fail? */
1103 if (result == USB_STOR_XFER_STALLED) {
1105 /* get the status again */
1106 US_DEBUGP("Attempting to get CSW (2nd try)...\n");
1107 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe,
1108 bcs, US_BULK_CS_WRAP_LEN, NULL);
1111 /* if we still have a failure at this point, we're in trouble */
1112 US_DEBUGP("Bulk status result = %d\n", result);
1113 if (result != USB_STOR_XFER_GOOD)
1114 return USB_STOR_TRANSPORT_ERROR;
1116 /* check bulk status */
1117 residue = le32_to_cpu(bcs->Residue);
1118 US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n",
1119 le32_to_cpu(bcs->Signature), bcs->Tag,
1120 residue, bcs->Status);
1121 if (!(bcs->Tag == us->tag || (us->fflags & US_FL_BULK_IGNORE_TAG)) ||
1122 bcs->Status > US_BULK_STAT_PHASE) {
1123 US_DEBUGP("Bulk logical error\n");
1124 return USB_STOR_TRANSPORT_ERROR;
1127 /* Some broken devices report odd signatures, so we do not check them
1128 * for validity against the spec. We store the first one we see,
1129 * and check subsequent transfers for validity against this signature.
1131 if (!us->bcs_signature) {
1132 us->bcs_signature = bcs->Signature;
1133 if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN))
1134 US_DEBUGP("Learnt BCS signature 0x%08X\n",
1135 le32_to_cpu(us->bcs_signature));
1136 } else if (bcs->Signature != us->bcs_signature) {
1137 US_DEBUGP("Signature mismatch: got %08X, expecting %08X\n",
1138 le32_to_cpu(bcs->Signature),
1139 le32_to_cpu(us->bcs_signature));
1140 return USB_STOR_TRANSPORT_ERROR;
1143 /* try to compute the actual residue, based on how much data
1144 * was really transferred and what the device tells us */
1145 if (residue && !(us->fflags & US_FL_IGNORE_RESIDUE)) {
1147 /* Heuristically detect devices that generate bogus residues
1148 * by seeing what happens with INQUIRY and READ CAPACITY
1149 * commands.
1151 if (bcs->Status == US_BULK_STAT_OK &&
1152 scsi_get_resid(srb) == 0 &&
1153 ((srb->cmnd[0] == INQUIRY &&
1154 transfer_length == 36) ||
1155 (srb->cmnd[0] == READ_CAPACITY &&
1156 transfer_length == 8))) {
1157 us->fflags |= US_FL_IGNORE_RESIDUE;
1159 } else {
1160 residue = min(residue, transfer_length);
1161 scsi_set_resid(srb, max(scsi_get_resid(srb),
1162 (int) residue));
1166 /* based on the status code, we report good or bad */
1167 switch (bcs->Status) {
1168 case US_BULK_STAT_OK:
1169 /* device babbled -- return fake sense data */
1170 if (fake_sense) {
1171 memcpy(srb->sense_buffer,
1172 usb_stor_sense_invalidCDB,
1173 sizeof(usb_stor_sense_invalidCDB));
1174 return USB_STOR_TRANSPORT_NO_SENSE;
1177 /* command good -- note that data could be short */
1178 return USB_STOR_TRANSPORT_GOOD;
1180 case US_BULK_STAT_FAIL:
1181 /* command failed */
1182 return USB_STOR_TRANSPORT_FAILED;
1184 case US_BULK_STAT_PHASE:
1185 /* phase error -- note that a transport reset will be
1186 * invoked by the invoke_transport() function
1188 return USB_STOR_TRANSPORT_ERROR;
1191 /* we should never get here, but if we do, we're in trouble */
1192 return USB_STOR_TRANSPORT_ERROR;
1194 EXPORT_SYMBOL_GPL(usb_stor_Bulk_transport);
1196 /***********************************************************************
1197 * Reset routines
1198 ***********************************************************************/
1200 /* This is the common part of the device reset code.
1202 * It's handy that every transport mechanism uses the control endpoint for
1203 * resets.
1205 * Basically, we send a reset with a 5-second timeout, so we don't get
1206 * jammed attempting to do the reset.
1208 static int usb_stor_reset_common(struct us_data *us,
1209 u8 request, u8 requesttype,
1210 u16 value, u16 index, void *data, u16 size)
1212 int result;
1213 int result2;
1215 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1216 US_DEBUGP("No reset during disconnect\n");
1217 return -EIO;
1220 result = usb_stor_control_msg(us, us->send_ctrl_pipe,
1221 request, requesttype, value, index, data, size,
1222 5*HZ);
1223 if (result < 0) {
1224 US_DEBUGP("Soft reset failed: %d\n", result);
1225 return result;
1228 /* Give the device some time to recover from the reset,
1229 * but don't delay disconnect processing. */
1230 wait_event_interruptible_timeout(us->delay_wait,
1231 test_bit(US_FLIDX_DISCONNECTING, &us->dflags),
1232 HZ*6);
1233 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1234 US_DEBUGP("Reset interrupted by disconnect\n");
1235 return -EIO;
1238 US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n");
1239 result = usb_stor_clear_halt(us, us->recv_bulk_pipe);
1241 US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n");
1242 result2 = usb_stor_clear_halt(us, us->send_bulk_pipe);
1244 /* return a result code based on the result of the clear-halts */
1245 if (result >= 0)
1246 result = result2;
1247 if (result < 0)
1248 US_DEBUGP("Soft reset failed\n");
1249 else
1250 US_DEBUGP("Soft reset done\n");
1251 return result;
1254 /* This issues a CB[I] Reset to the device in question
1256 #define CB_RESET_CMD_SIZE 12
1258 int usb_stor_CB_reset(struct us_data *us)
1260 US_DEBUGP("%s called\n", __func__);
1262 memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE);
1263 us->iobuf[0] = SEND_DIAGNOSTIC;
1264 us->iobuf[1] = 4;
1265 return usb_stor_reset_common(us, US_CBI_ADSC,
1266 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1267 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE);
1269 EXPORT_SYMBOL_GPL(usb_stor_CB_reset);
1271 /* This issues a Bulk-only Reset to the device in question, including
1272 * clearing the subsequent endpoint halts that may occur.
1274 int usb_stor_Bulk_reset(struct us_data *us)
1276 US_DEBUGP("%s called\n", __func__);
1278 return usb_stor_reset_common(us, US_BULK_RESET_REQUEST,
1279 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
1280 0, us->ifnum, NULL, 0);
1282 EXPORT_SYMBOL_GPL(usb_stor_Bulk_reset);
1284 /* Issue a USB port reset to the device. The caller must not hold
1285 * us->dev_mutex.
1287 int usb_stor_port_reset(struct us_data *us)
1289 int result;
1291 result = usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf);
1292 if (result < 0)
1293 US_DEBUGP("unable to lock device for reset: %d\n", result);
1294 else {
1295 /* Were we disconnected while waiting for the lock? */
1296 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
1297 result = -EIO;
1298 US_DEBUGP("No reset during disconnect\n");
1299 } else {
1300 result = usb_reset_device(us->pusb_dev);
1301 US_DEBUGP("usb_reset_device returns %d\n",
1302 result);
1304 usb_unlock_device(us->pusb_dev);
1306 return result;