1 /* Driver for USB Mass Storage compliant devices 2 * 3 * $Id: transport.c,v 1.47 2002/04/22 03:39:43 mdharm Exp $ 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 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more 31 * information about this driver. 32 * 33 * This program is free software; you can redistribute it and/or modify it 34 * under the terms of the GNU General Public License as published by the 35 * Free Software Foundation; either version 2, or (at your option) any 36 * later version. 37 * 38 * This program is distributed in the hope that it will be useful, but 39 * WITHOUT ANY WARRANTY; without even the implied warranty of 40 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 41 * General Public License for more details. 42 * 43 * You should have received a copy of the GNU General Public License along 44 * with this program; if not, write to the Free Software Foundation, Inc., 45 * 675 Mass Ave, Cambridge, MA 02139, USA. 46 */ 47 48 #include <linux/config.h> 49 #include <linux/sched.h> 50 #include <linux/errno.h> 51 #include <linux/slab.h> 52 53 #include <scsi/scsi.h> 54 #include <scsi/scsi_cmnd.h> 55 #include <scsi/scsi_device.h> 56 57 #include "usb.h" 58 #include "transport.h" 59 #include "protocol.h" 60 #include "scsiglue.h" 61 #include "debug.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->flags 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->flags 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->flags 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, struct pt_regs *regs) 113 { 114 struct completion *urb_done_ptr = (struct completion *)urb->context; 115 116 complete(urb_done_ptr); 117 } 118 119 /* This is the timeout handler which will cancel an URB when its timeout 120 * expires. 121 */ 122 static void timeout_handler(unsigned long us_) 123 { 124 struct us_data *us = (struct us_data *) us_; 125 126 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) { 127 US_DEBUGP("Timeout -- cancelling URB\n"); 128 usb_unlink_urb(us->current_urb); 129 } 130 } 131 132 /* This is the common part of the URB message submission code 133 * 134 * All URBs from the usb-storage driver involved in handling a queued scsi 135 * command _must_ pass through this function (or something like it) for the 136 * abort mechanisms to work properly. 137 */ 138 static int usb_stor_msg_common(struct us_data *us, int timeout) 139 { 140 struct completion urb_done; 141 struct timer_list to_timer; 142 int status; 143 144 /* don't submit URBs during abort/disconnect processing */ 145 if (us->flags & ABORTING_OR_DISCONNECTING) 146 return -EIO; 147 148 /* set up data structures for the wakeup system */ 149 init_completion(&urb_done); 150 151 /* fill the common fields in the URB */ 152 us->current_urb->context = &urb_done; 153 us->current_urb->actual_length = 0; 154 us->current_urb->error_count = 0; 155 us->current_urb->status = 0; 156 157 /* we assume that if transfer_buffer isn't us->iobuf then it 158 * hasn't been mapped for DMA. Yes, this is clunky, but it's 159 * easier than always having the caller tell us whether the 160 * transfer buffer has already been mapped. */ 161 us->current_urb->transfer_flags = URB_NO_SETUP_DMA_MAP; 162 if (us->current_urb->transfer_buffer == us->iobuf) 163 us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 164 us->current_urb->transfer_dma = us->iobuf_dma; 165 us->current_urb->setup_dma = us->cr_dma; 166 167 /* submit the URB */ 168 status = usb_submit_urb(us->current_urb, GFP_NOIO); 169 if (status) { 170 /* something went wrong */ 171 return status; 172 } 173 174 /* since the URB has been submitted successfully, it's now okay 175 * to cancel it */ 176 set_bit(US_FLIDX_URB_ACTIVE, &us->flags); 177 178 /* did an abort/disconnect occur during the submission? */ 179 if (us->flags & ABORTING_OR_DISCONNECTING) { 180 181 /* cancel the URB, if it hasn't been cancelled already */ 182 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) { 183 US_DEBUGP("-- cancelling URB\n"); 184 usb_unlink_urb(us->current_urb); 185 } 186 } 187 188 /* submit the timeout timer, if a timeout was requested */ 189 if (timeout > 0) { 190 init_timer(&to_timer); 191 to_timer.expires = jiffies + timeout; 192 to_timer.function = timeout_handler; 193 to_timer.data = (unsigned long) us; 194 add_timer(&to_timer); 195 } 196 197 /* wait for the completion of the URB */ 198 wait_for_completion(&urb_done); 199 clear_bit(US_FLIDX_URB_ACTIVE, &us->flags); 200 201 /* clean up the timeout timer */ 202 if (timeout > 0) 203 del_timer_sync(&to_timer); 204 205 /* return the URB status */ 206 return us->current_urb->status; 207 } 208 209 /* 210 * Transfer one control message, with timeouts, and allowing early 211 * termination. Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx. 212 */ 213 int usb_stor_control_msg(struct us_data *us, unsigned int pipe, 214 u8 request, u8 requesttype, u16 value, u16 index, 215 void *data, u16 size, int timeout) 216 { 217 int status; 218 219 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n", 220 __FUNCTION__, request, requesttype, 221 value, index, size); 222 223 /* fill in the devrequest structure */ 224 us->cr->bRequestType = requesttype; 225 us->cr->bRequest = request; 226 us->cr->wValue = cpu_to_le16(value); 227 us->cr->wIndex = cpu_to_le16(index); 228 us->cr->wLength = cpu_to_le16(size); 229 230 /* fill and submit the URB */ 231 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe, 232 (unsigned char*) us->cr, data, size, 233 usb_stor_blocking_completion, NULL); 234 status = usb_stor_msg_common(us, timeout); 235 236 /* return the actual length of the data transferred if no error */ 237 if (status == 0) 238 status = us->current_urb->actual_length; 239 return status; 240 } 241 242 /* This is a version of usb_clear_halt() that allows early termination and 243 * doesn't read the status from the device -- this is because some devices 244 * crash their internal firmware when the status is requested after a halt. 245 * 246 * A definitive list of these 'bad' devices is too difficult to maintain or 247 * make complete enough to be useful. This problem was first observed on the 248 * Hagiwara FlashGate DUAL unit. However, bus traces reveal that neither 249 * MacOS nor Windows checks the status after clearing a halt. 250 * 251 * Since many vendors in this space limit their testing to interoperability 252 * with these two OSes, specification violations like this one are common. 253 */ 254 int usb_stor_clear_halt(struct us_data *us, unsigned int pipe) 255 { 256 int result; 257 int endp = usb_pipeendpoint(pipe); 258 259 if (usb_pipein (pipe)) 260 endp |= USB_DIR_IN; 261 262 result = usb_stor_control_msg(us, us->send_ctrl_pipe, 263 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT, 264 USB_ENDPOINT_HALT, endp, 265 NULL, 0, 3*HZ); 266 267 /* reset the endpoint toggle */ 268 if (result >= 0) 269 usb_settoggle(us->pusb_dev, usb_pipeendpoint(pipe), 270 usb_pipeout(pipe), 0); 271 272 US_DEBUGP("%s: result = %d\n", __FUNCTION__, result); 273 return result; 274 } 275 276 277 /* 278 * Interpret the results of a URB transfer 279 * 280 * This function prints appropriate debugging messages, clears halts on 281 * non-control endpoints, and translates the status to the corresponding 282 * USB_STOR_XFER_xxx return code. 283 */ 284 static int interpret_urb_result(struct us_data *us, unsigned int pipe, 285 unsigned int length, int result, unsigned int partial) 286 { 287 US_DEBUGP("Status code %d; transferred %u/%u\n", 288 result, partial, length); 289 switch (result) { 290 291 /* no error code; did we send all the data? */ 292 case 0: 293 if (partial != length) { 294 US_DEBUGP("-- short transfer\n"); 295 return USB_STOR_XFER_SHORT; 296 } 297 298 US_DEBUGP("-- transfer complete\n"); 299 return USB_STOR_XFER_GOOD; 300 301 /* stalled */ 302 case -EPIPE: 303 /* for control endpoints, (used by CB[I]) a stall indicates 304 * a failed command */ 305 if (usb_pipecontrol(pipe)) { 306 US_DEBUGP("-- stall on control pipe\n"); 307 return USB_STOR_XFER_STALLED; 308 } 309 310 /* for other sorts of endpoint, clear the stall */ 311 US_DEBUGP("clearing endpoint halt for pipe 0x%x\n", pipe); 312 if (usb_stor_clear_halt(us, pipe) < 0) 313 return USB_STOR_XFER_ERROR; 314 return USB_STOR_XFER_STALLED; 315 316 /* timeout or excessively long NAK */ 317 case -ETIMEDOUT: 318 US_DEBUGP("-- timeout or NAK\n"); 319 return USB_STOR_XFER_ERROR; 320 321 /* babble - the device tried to send more than we wanted to read */ 322 case -EOVERFLOW: 323 US_DEBUGP("-- babble\n"); 324 return USB_STOR_XFER_LONG; 325 326 /* the transfer was cancelled by abort, disconnect, or timeout */ 327 case -ECONNRESET: 328 US_DEBUGP("-- transfer cancelled\n"); 329 return USB_STOR_XFER_ERROR; 330 331 /* short scatter-gather read transfer */ 332 case -EREMOTEIO: 333 US_DEBUGP("-- short read transfer\n"); 334 return USB_STOR_XFER_SHORT; 335 336 /* abort or disconnect in progress */ 337 case -EIO: 338 US_DEBUGP("-- abort or disconnect in progress\n"); 339 return USB_STOR_XFER_ERROR; 340 341 /* the catch-all error case */ 342 default: 343 US_DEBUGP("-- unknown error\n"); 344 return USB_STOR_XFER_ERROR; 345 } 346 } 347 348 /* 349 * Transfer one control message, without timeouts, but allowing early 350 * termination. Return codes are USB_STOR_XFER_xxx. 351 */ 352 int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe, 353 u8 request, u8 requesttype, u16 value, u16 index, 354 void *data, u16 size) 355 { 356 int result; 357 358 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n", 359 __FUNCTION__, request, requesttype, 360 value, index, size); 361 362 /* fill in the devrequest structure */ 363 us->cr->bRequestType = requesttype; 364 us->cr->bRequest = request; 365 us->cr->wValue = cpu_to_le16(value); 366 us->cr->wIndex = cpu_to_le16(index); 367 us->cr->wLength = cpu_to_le16(size); 368 369 /* fill and submit the URB */ 370 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe, 371 (unsigned char*) us->cr, data, size, 372 usb_stor_blocking_completion, NULL); 373 result = usb_stor_msg_common(us, 0); 374 375 return interpret_urb_result(us, pipe, size, result, 376 us->current_urb->actual_length); 377 } 378 379 /* 380 * Receive one interrupt buffer, without timeouts, but allowing early 381 * termination. Return codes are USB_STOR_XFER_xxx. 382 * 383 * This routine always uses us->recv_intr_pipe as the pipe and 384 * us->ep_bInterval as the interrupt interval. 385 */ 386 static int usb_stor_intr_transfer(struct us_data *us, void *buf, 387 unsigned int length) 388 { 389 int result; 390 unsigned int pipe = us->recv_intr_pipe; 391 unsigned int maxp; 392 393 US_DEBUGP("%s: xfer %u bytes\n", __FUNCTION__, length); 394 395 /* calculate the max packet size */ 396 maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe)); 397 if (maxp > length) 398 maxp = length; 399 400 /* fill and submit the URB */ 401 usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf, 402 maxp, usb_stor_blocking_completion, NULL, 403 us->ep_bInterval); 404 result = usb_stor_msg_common(us, 0); 405 406 return interpret_urb_result(us, pipe, length, result, 407 us->current_urb->actual_length); 408 } 409 410 /* 411 * Transfer one buffer via bulk pipe, without timeouts, but allowing early 412 * termination. Return codes are USB_STOR_XFER_xxx. If the bulk pipe 413 * stalls during the transfer, the halt is automatically cleared. 414 */ 415 int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe, 416 void *buf, unsigned int length, unsigned int *act_len) 417 { 418 int result; 419 420 US_DEBUGP("%s: xfer %u bytes\n", __FUNCTION__, length); 421 422 /* fill and submit the URB */ 423 usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length, 424 usb_stor_blocking_completion, NULL); 425 result = usb_stor_msg_common(us, 0); 426 427 /* store the actual length of the data transferred */ 428 if (act_len) 429 *act_len = us->current_urb->actual_length; 430 return interpret_urb_result(us, pipe, length, result, 431 us->current_urb->actual_length); 432 } 433 434 /* 435 * Transfer a scatter-gather list via bulk transfer 436 * 437 * This function does basically the same thing as usb_stor_bulk_transfer_buf() 438 * above, but it uses the usbcore scatter-gather library. 439 */ 440 static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe, 441 struct scatterlist *sg, int num_sg, unsigned int length, 442 unsigned int *act_len) 443 { 444 int result; 445 446 /* don't submit s-g requests during abort/disconnect processing */ 447 if (us->flags & ABORTING_OR_DISCONNECTING) 448 return USB_STOR_XFER_ERROR; 449 450 /* initialize the scatter-gather request block */ 451 US_DEBUGP("%s: xfer %u bytes, %d entries\n", __FUNCTION__, 452 length, num_sg); 453 result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0, 454 sg, num_sg, length, SLAB_NOIO); 455 if (result) { 456 US_DEBUGP("usb_sg_init returned %d\n", result); 457 return USB_STOR_XFER_ERROR; 458 } 459 460 /* since the block has been initialized successfully, it's now 461 * okay to cancel it */ 462 set_bit(US_FLIDX_SG_ACTIVE, &us->flags); 463 464 /* did an abort/disconnect occur during the submission? */ 465 if (us->flags & ABORTING_OR_DISCONNECTING) { 466 467 /* cancel the request, if it hasn't been cancelled already */ 468 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) { 469 US_DEBUGP("-- cancelling sg request\n"); 470 usb_sg_cancel(&us->current_sg); 471 } 472 } 473 474 /* wait for the completion of the transfer */ 475 usb_sg_wait(&us->current_sg); 476 clear_bit(US_FLIDX_SG_ACTIVE, &us->flags); 477 478 result = us->current_sg.status; 479 if (act_len) 480 *act_len = us->current_sg.bytes; 481 return interpret_urb_result(us, pipe, length, result, 482 us->current_sg.bytes); 483 } 484 485 /* 486 * Transfer an entire SCSI command's worth of data payload over the bulk 487 * pipe. 488 * 489 * Note that this uses usb_stor_bulk_transfer_buf() and 490 * usb_stor_bulk_transfer_sglist() to achieve its goals -- 491 * this function simply determines whether we're going to use 492 * scatter-gather or not, and acts appropriately. 493 */ 494 int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe, 495 void *buf, unsigned int length_left, int use_sg, int *residual) 496 { 497 int result; 498 unsigned int partial; 499 500 /* are we scatter-gathering? */ 501 if (use_sg) { 502 /* use the usb core scatter-gather primitives */ 503 result = usb_stor_bulk_transfer_sglist(us, pipe, 504 (struct scatterlist *) buf, use_sg, 505 length_left, &partial); 506 length_left -= partial; 507 } else { 508 /* no scatter-gather, just make the request */ 509 result = usb_stor_bulk_transfer_buf(us, pipe, buf, 510 length_left, &partial); 511 length_left -= partial; 512 } 513 514 /* store the residual and return the error code */ 515 if (residual) 516 *residual = length_left; 517 return result; 518 } 519 520 /*********************************************************************** 521 * Transport routines 522 ***********************************************************************/ 523 524 /* Invoke the transport and basic error-handling/recovery methods 525 * 526 * This is used by the protocol layers to actually send the message to 527 * the device and receive the response. 528 */ 529 void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us) 530 { 531 int need_auto_sense; 532 int result; 533 534 /* send the command to the transport layer */ 535 srb->resid = 0; 536 result = us->transport(srb, us); 537 538 /* if the command gets aborted by the higher layers, we need to 539 * short-circuit all other processing 540 */ 541 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) { 542 US_DEBUGP("-- command was aborted\n"); 543 srb->result = DID_ABORT << 16; 544 goto Handle_Errors; 545 } 546 547 /* if there is a transport error, reset and don't auto-sense */ 548 if (result == USB_STOR_TRANSPORT_ERROR) { 549 US_DEBUGP("-- transport indicates error, resetting\n"); 550 srb->result = DID_ERROR << 16; 551 goto Handle_Errors; 552 } 553 554 /* if the transport provided its own sense data, don't auto-sense */ 555 if (result == USB_STOR_TRANSPORT_NO_SENSE) { 556 srb->result = SAM_STAT_CHECK_CONDITION; 557 return; 558 } 559 560 srb->result = SAM_STAT_GOOD; 561 562 /* Determine if we need to auto-sense 563 * 564 * I normally don't use a flag like this, but it's almost impossible 565 * to understand what's going on here if I don't. 566 */ 567 need_auto_sense = 0; 568 569 /* 570 * If we're running the CB transport, which is incapable 571 * of determining status on its own, we will auto-sense 572 * unless the operation involved a data-in transfer. Devices 573 * can signal most data-in errors by stalling the bulk-in pipe. 574 */ 575 if ((us->protocol == US_PR_CB || us->protocol == US_PR_DPCM_USB) && 576 srb->sc_data_direction != DMA_FROM_DEVICE) { 577 US_DEBUGP("-- CB transport device requiring auto-sense\n"); 578 need_auto_sense = 1; 579 } 580 581 /* 582 * If we have a failure, we're going to do a REQUEST_SENSE 583 * automatically. Note that we differentiate between a command 584 * "failure" and an "error" in the transport mechanism. 585 */ 586 if (result == USB_STOR_TRANSPORT_FAILED) { 587 US_DEBUGP("-- transport indicates command failure\n"); 588 need_auto_sense = 1; 589 } 590 591 /* 592 * A short transfer on a command where we don't expect it 593 * is unusual, but it doesn't mean we need to auto-sense. 594 */ 595 if ((srb->resid > 0) && 596 !((srb->cmnd[0] == REQUEST_SENSE) || 597 (srb->cmnd[0] == INQUIRY) || 598 (srb->cmnd[0] == MODE_SENSE) || 599 (srb->cmnd[0] == LOG_SENSE) || 600 (srb->cmnd[0] == MODE_SENSE_10))) { 601 US_DEBUGP("-- unexpectedly short transfer\n"); 602 } 603 604 /* Now, if we need to do the auto-sense, let's do it */ 605 if (need_auto_sense) { 606 int temp_result; 607 void* old_request_buffer; 608 unsigned short old_sg; 609 unsigned old_request_bufflen; 610 unsigned char old_sc_data_direction; 611 unsigned char old_cmd_len; 612 unsigned char old_cmnd[MAX_COMMAND_SIZE]; 613 int old_resid; 614 615 US_DEBUGP("Issuing auto-REQUEST_SENSE\n"); 616 617 /* save the old command */ 618 memcpy(old_cmnd, srb->cmnd, MAX_COMMAND_SIZE); 619 old_cmd_len = srb->cmd_len; 620 621 /* set the command and the LUN */ 622 memset(srb->cmnd, 0, MAX_COMMAND_SIZE); 623 srb->cmnd[0] = REQUEST_SENSE; 624 srb->cmnd[1] = old_cmnd[1] & 0xE0; 625 srb->cmnd[4] = 18; 626 627 /* FIXME: we must do the protocol translation here */ 628 if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI) 629 srb->cmd_len = 6; 630 else 631 srb->cmd_len = 12; 632 633 /* set the transfer direction */ 634 old_sc_data_direction = srb->sc_data_direction; 635 srb->sc_data_direction = DMA_FROM_DEVICE; 636 637 /* use the new buffer we have */ 638 old_request_buffer = srb->request_buffer; 639 srb->request_buffer = srb->sense_buffer; 640 641 /* set the buffer length for transfer */ 642 old_request_bufflen = srb->request_bufflen; 643 srb->request_bufflen = 18; 644 645 /* set up for no scatter-gather use */ 646 old_sg = srb->use_sg; 647 srb->use_sg = 0; 648 649 /* issue the auto-sense command */ 650 old_resid = srb->resid; 651 srb->resid = 0; 652 temp_result = us->transport(us->srb, us); 653 654 /* let's clean up right away */ 655 srb->resid = old_resid; 656 srb->request_buffer = old_request_buffer; 657 srb->request_bufflen = old_request_bufflen; 658 srb->use_sg = old_sg; 659 srb->sc_data_direction = old_sc_data_direction; 660 srb->cmd_len = old_cmd_len; 661 memcpy(srb->cmnd, old_cmnd, MAX_COMMAND_SIZE); 662 663 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) { 664 US_DEBUGP("-- auto-sense aborted\n"); 665 srb->result = DID_ABORT << 16; 666 goto Handle_Errors; 667 } 668 if (temp_result != USB_STOR_TRANSPORT_GOOD) { 669 US_DEBUGP("-- auto-sense failure\n"); 670 671 /* we skip the reset if this happens to be a 672 * multi-target device, since failure of an 673 * auto-sense is perfectly valid 674 */ 675 srb->result = DID_ERROR << 16; 676 if (!(us->flags & US_FL_SCM_MULT_TARG)) 677 goto Handle_Errors; 678 return; 679 } 680 681 US_DEBUGP("-- Result from auto-sense is %d\n", temp_result); 682 US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n", 683 srb->sense_buffer[0], 684 srb->sense_buffer[2] & 0xf, 685 srb->sense_buffer[12], 686 srb->sense_buffer[13]); 687 #ifdef CONFIG_USB_STORAGE_DEBUG 688 usb_stor_show_sense( 689 srb->sense_buffer[2] & 0xf, 690 srb->sense_buffer[12], 691 srb->sense_buffer[13]); 692 #endif 693 694 /* set the result so the higher layers expect this data */ 695 srb->result = SAM_STAT_CHECK_CONDITION; 696 697 /* If things are really okay, then let's show that. Zero 698 * out the sense buffer so the higher layers won't realize 699 * we did an unsolicited auto-sense. */ 700 if (result == USB_STOR_TRANSPORT_GOOD && 701 /* Filemark 0, ignore EOM, ILI 0, no sense */ 702 (srb->sense_buffer[2] & 0xaf) == 0 && 703 /* No ASC or ASCQ */ 704 srb->sense_buffer[12] == 0 && 705 srb->sense_buffer[13] == 0) { 706 srb->result = SAM_STAT_GOOD; 707 srb->sense_buffer[0] = 0x0; 708 } 709 } 710 711 /* Did we transfer less than the minimum amount required? */ 712 if (srb->result == SAM_STAT_GOOD && 713 srb->request_bufflen - srb->resid < srb->underflow) 714 srb->result = (DID_ERROR << 16) | (SUGGEST_RETRY << 24); 715 716 return; 717 718 /* Error and abort processing: try to resynchronize with the device 719 * by issuing a port reset. If that fails, try a class-specific 720 * device reset. */ 721 Handle_Errors: 722 723 /* Let the SCSI layer know we are doing a reset, set the 724 * RESETTING bit, and clear the ABORTING bit so that the reset 725 * may proceed. */ 726 scsi_lock(us_to_host(us)); 727 usb_stor_report_bus_reset(us); 728 set_bit(US_FLIDX_RESETTING, &us->flags); 729 clear_bit(US_FLIDX_ABORTING, &us->flags); 730 scsi_unlock(us_to_host(us)); 731 732 result = usb_stor_port_reset(us); 733 if (result < 0) { 734 scsi_lock(us_to_host(us)); 735 usb_stor_report_device_reset(us); 736 scsi_unlock(us_to_host(us)); 737 us->transport_reset(us); 738 } 739 clear_bit(US_FLIDX_RESETTING, &us->flags); 740 } 741 742 /* Stop the current URB transfer */ 743 void usb_stor_stop_transport(struct us_data *us) 744 { 745 US_DEBUGP("%s called\n", __FUNCTION__); 746 747 /* If the state machine is blocked waiting for an URB, 748 * let's wake it up. The test_and_clear_bit() call 749 * guarantees that if a URB has just been submitted, 750 * it won't be cancelled more than once. */ 751 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) { 752 US_DEBUGP("-- cancelling URB\n"); 753 usb_unlink_urb(us->current_urb); 754 } 755 756 /* If we are waiting for a scatter-gather operation, cancel it. */ 757 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) { 758 US_DEBUGP("-- cancelling sg request\n"); 759 usb_sg_cancel(&us->current_sg); 760 } 761 } 762 763 /* 764 * Control/Bulk/Interrupt transport 765 */ 766 767 int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us) 768 { 769 unsigned int transfer_length = srb->request_bufflen; 770 unsigned int pipe = 0; 771 int result; 772 773 /* COMMAND STAGE */ 774 /* let's send the command via the control pipe */ 775 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe, 776 US_CBI_ADSC, 777 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, 778 us->ifnum, srb->cmnd, srb->cmd_len); 779 780 /* check the return code for the command */ 781 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result); 782 783 /* if we stalled the command, it means command failed */ 784 if (result == USB_STOR_XFER_STALLED) { 785 return USB_STOR_TRANSPORT_FAILED; 786 } 787 788 /* Uh oh... serious problem here */ 789 if (result != USB_STOR_XFER_GOOD) { 790 return USB_STOR_TRANSPORT_ERROR; 791 } 792 793 /* DATA STAGE */ 794 /* transfer the data payload for this command, if one exists*/ 795 if (transfer_length) { 796 pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 797 us->recv_bulk_pipe : us->send_bulk_pipe; 798 result = usb_stor_bulk_transfer_sg(us, pipe, 799 srb->request_buffer, transfer_length, 800 srb->use_sg, &srb->resid); 801 US_DEBUGP("CBI data stage result is 0x%x\n", result); 802 803 /* if we stalled the data transfer it means command failed */ 804 if (result == USB_STOR_XFER_STALLED) 805 return USB_STOR_TRANSPORT_FAILED; 806 if (result > USB_STOR_XFER_STALLED) 807 return USB_STOR_TRANSPORT_ERROR; 808 } 809 810 /* STATUS STAGE */ 811 result = usb_stor_intr_transfer(us, us->iobuf, 2); 812 US_DEBUGP("Got interrupt data (0x%x, 0x%x)\n", 813 us->iobuf[0], us->iobuf[1]); 814 if (result != USB_STOR_XFER_GOOD) 815 return USB_STOR_TRANSPORT_ERROR; 816 817 /* UFI gives us ASC and ASCQ, like a request sense 818 * 819 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI 820 * devices, so we ignore the information for those commands. Note 821 * that this means we could be ignoring a real error on these 822 * commands, but that can't be helped. 823 */ 824 if (us->subclass == US_SC_UFI) { 825 if (srb->cmnd[0] == REQUEST_SENSE || 826 srb->cmnd[0] == INQUIRY) 827 return USB_STOR_TRANSPORT_GOOD; 828 if (us->iobuf[0]) 829 goto Failed; 830 return USB_STOR_TRANSPORT_GOOD; 831 } 832 833 /* If not UFI, we interpret the data as a result code 834 * The first byte should always be a 0x0. 835 * 836 * Some bogus devices don't follow that rule. They stuff the ASC 837 * into the first byte -- so if it's non-zero, call it a failure. 838 */ 839 if (us->iobuf[0]) { 840 US_DEBUGP("CBI IRQ data showed reserved bType 0x%x\n", 841 us->iobuf[0]); 842 goto Failed; 843 844 } 845 846 /* The second byte & 0x0F should be 0x0 for good, otherwise error */ 847 switch (us->iobuf[1] & 0x0F) { 848 case 0x00: 849 return USB_STOR_TRANSPORT_GOOD; 850 case 0x01: 851 goto Failed; 852 } 853 return USB_STOR_TRANSPORT_ERROR; 854 855 /* the CBI spec requires that the bulk pipe must be cleared 856 * following any data-in/out command failure (section 2.4.3.1.3) 857 */ 858 Failed: 859 if (pipe) 860 usb_stor_clear_halt(us, pipe); 861 return USB_STOR_TRANSPORT_FAILED; 862 } 863 864 /* 865 * Control/Bulk transport 866 */ 867 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us) 868 { 869 unsigned int transfer_length = srb->request_bufflen; 870 int result; 871 872 /* COMMAND STAGE */ 873 /* let's send the command via the control pipe */ 874 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe, 875 US_CBI_ADSC, 876 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, 877 us->ifnum, srb->cmnd, srb->cmd_len); 878 879 /* check the return code for the command */ 880 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result); 881 882 /* if we stalled the command, it means command failed */ 883 if (result == USB_STOR_XFER_STALLED) { 884 return USB_STOR_TRANSPORT_FAILED; 885 } 886 887 /* Uh oh... serious problem here */ 888 if (result != USB_STOR_XFER_GOOD) { 889 return USB_STOR_TRANSPORT_ERROR; 890 } 891 892 /* DATA STAGE */ 893 /* transfer the data payload for this command, if one exists*/ 894 if (transfer_length) { 895 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 896 us->recv_bulk_pipe : us->send_bulk_pipe; 897 result = usb_stor_bulk_transfer_sg(us, pipe, 898 srb->request_buffer, transfer_length, 899 srb->use_sg, &srb->resid); 900 US_DEBUGP("CB data stage result is 0x%x\n", result); 901 902 /* if we stalled the data transfer it means command failed */ 903 if (result == USB_STOR_XFER_STALLED) 904 return USB_STOR_TRANSPORT_FAILED; 905 if (result > USB_STOR_XFER_STALLED) 906 return USB_STOR_TRANSPORT_ERROR; 907 } 908 909 /* STATUS STAGE */ 910 /* NOTE: CB does not have a status stage. Silly, I know. So 911 * we have to catch this at a higher level. 912 */ 913 return USB_STOR_TRANSPORT_GOOD; 914 } 915 916 /* 917 * Bulk only transport 918 */ 919 920 /* Determine what the maximum LUN supported is */ 921 int usb_stor_Bulk_max_lun(struct us_data *us) 922 { 923 int result; 924 925 /* issue the command */ 926 result = usb_stor_control_msg(us, us->recv_ctrl_pipe, 927 US_BULK_GET_MAX_LUN, 928 USB_DIR_IN | USB_TYPE_CLASS | 929 USB_RECIP_INTERFACE, 930 0, us->ifnum, us->iobuf, 1, HZ); 931 932 US_DEBUGP("GetMaxLUN command result is %d, data is %d\n", 933 result, us->iobuf[0]); 934 935 /* if we have a successful request, return the result */ 936 if (result > 0) 937 return us->iobuf[0]; 938 939 /* 940 * Some devices (i.e. Iomega Zip100) need this -- apparently 941 * the bulk pipes get STALLed when the GetMaxLUN request is 942 * processed. This is, in theory, harmless to all other devices 943 * (regardless of if they stall or not). 944 */ 945 if (result == -EPIPE) { 946 usb_stor_clear_halt(us, us->recv_bulk_pipe); 947 usb_stor_clear_halt(us, us->send_bulk_pipe); 948 } 949 950 /* 951 * Some devices don't like GetMaxLUN. They may STALL the control 952 * pipe, they may return a zero-length result, they may do nothing at 953 * all and timeout, or they may fail in even more bizarrely creative 954 * ways. In these cases the best approach is to use the default 955 * value: only one LUN. 956 */ 957 return 0; 958 } 959 960 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us) 961 { 962 struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf; 963 struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf; 964 unsigned int transfer_length = srb->request_bufflen; 965 unsigned int residue; 966 int result; 967 int fake_sense = 0; 968 unsigned int cswlen; 969 unsigned int cbwlen = US_BULK_CB_WRAP_LEN; 970 971 /* Take care of BULK32 devices; set extra byte to 0 */ 972 if ( unlikely(us->flags & US_FL_BULK32)) { 973 cbwlen = 32; 974 us->iobuf[31] = 0; 975 } 976 977 /* set up the command wrapper */ 978 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN); 979 bcb->DataTransferLength = cpu_to_le32(transfer_length); 980 bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0; 981 bcb->Tag = ++us->tag; 982 bcb->Lun = srb->device->lun; 983 if (us->flags & US_FL_SCM_MULT_TARG) 984 bcb->Lun |= srb->device->id << 4; 985 bcb->Length = srb->cmd_len; 986 987 /* copy the command payload */ 988 memset(bcb->CDB, 0, sizeof(bcb->CDB)); 989 memcpy(bcb->CDB, srb->cmnd, bcb->Length); 990 991 /* send it to out endpoint */ 992 US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n", 993 le32_to_cpu(bcb->Signature), bcb->Tag, 994 le32_to_cpu(bcb->DataTransferLength), bcb->Flags, 995 (bcb->Lun >> 4), (bcb->Lun & 0x0F), 996 bcb->Length); 997 result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe, 998 bcb, cbwlen, NULL); 999 US_DEBUGP("Bulk command transfer result=%d\n", result); 1000 if (result != USB_STOR_XFER_GOOD) 1001 return USB_STOR_TRANSPORT_ERROR; 1002 1003 /* DATA STAGE */ 1004 /* send/receive data payload, if there is any */ 1005 1006 /* Some USB-IDE converter chips need a 100us delay between the 1007 * command phase and the data phase. Some devices need a little 1008 * more than that, probably because of clock rate inaccuracies. */ 1009 if (unlikely(us->flags & US_FL_GO_SLOW)) 1010 udelay(125); 1011 1012 if (transfer_length) { 1013 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 1014 us->recv_bulk_pipe : us->send_bulk_pipe; 1015 result = usb_stor_bulk_transfer_sg(us, pipe, 1016 srb->request_buffer, transfer_length, 1017 srb->use_sg, &srb->resid); 1018 US_DEBUGP("Bulk data transfer result 0x%x\n", result); 1019 if (result == USB_STOR_XFER_ERROR) 1020 return USB_STOR_TRANSPORT_ERROR; 1021 1022 /* If the device tried to send back more data than the 1023 * amount requested, the spec requires us to transfer 1024 * the CSW anyway. Since there's no point retrying the 1025 * the command, we'll return fake sense data indicating 1026 * Illegal Request, Invalid Field in CDB. 1027 */ 1028 if (result == USB_STOR_XFER_LONG) 1029 fake_sense = 1; 1030 } 1031 1032 /* See flow chart on pg 15 of the Bulk Only Transport spec for 1033 * an explanation of how this code works. 1034 */ 1035 1036 /* get CSW for device status */ 1037 US_DEBUGP("Attempting to get CSW...\n"); 1038 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 1039 bcs, US_BULK_CS_WRAP_LEN, &cswlen); 1040 1041 /* Some broken devices add unnecessary zero-length packets to the 1042 * end of their data transfers. Such packets show up as 0-length 1043 * CSWs. If we encounter such a thing, try to read the CSW again. 1044 */ 1045 if (result == USB_STOR_XFER_SHORT && cswlen == 0) { 1046 US_DEBUGP("Received 0-length CSW; retrying...\n"); 1047 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 1048 bcs, US_BULK_CS_WRAP_LEN, &cswlen); 1049 } 1050 1051 /* did the attempt to read the CSW fail? */ 1052 if (result == USB_STOR_XFER_STALLED) { 1053 1054 /* get the status again */ 1055 US_DEBUGP("Attempting to get CSW (2nd try)...\n"); 1056 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 1057 bcs, US_BULK_CS_WRAP_LEN, NULL); 1058 } 1059 1060 /* if we still have a failure at this point, we're in trouble */ 1061 US_DEBUGP("Bulk status result = %d\n", result); 1062 if (result != USB_STOR_XFER_GOOD) 1063 return USB_STOR_TRANSPORT_ERROR; 1064 1065 /* check bulk status */ 1066 residue = le32_to_cpu(bcs->Residue); 1067 US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n", 1068 le32_to_cpu(bcs->Signature), bcs->Tag, 1069 residue, bcs->Status); 1070 if (bcs->Tag != us->tag || bcs->Status > US_BULK_STAT_PHASE) { 1071 US_DEBUGP("Bulk logical error\n"); 1072 return USB_STOR_TRANSPORT_ERROR; 1073 } 1074 1075 /* Some broken devices report odd signatures, so we do not check them 1076 * for validity against the spec. We store the first one we see, 1077 * and check subsequent transfers for validity against this signature. 1078 */ 1079 if (!us->bcs_signature) { 1080 us->bcs_signature = bcs->Signature; 1081 if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN)) 1082 US_DEBUGP("Learnt BCS signature 0x%08X\n", 1083 le32_to_cpu(us->bcs_signature)); 1084 } else if (bcs->Signature != us->bcs_signature) { 1085 US_DEBUGP("Signature mismatch: got %08X, expecting %08X\n", 1086 le32_to_cpu(bcs->Signature), 1087 le32_to_cpu(us->bcs_signature)); 1088 return USB_STOR_TRANSPORT_ERROR; 1089 } 1090 1091 /* try to compute the actual residue, based on how much data 1092 * was really transferred and what the device tells us */ 1093 if (residue) { 1094 if (!(us->flags & US_FL_IGNORE_RESIDUE)) { 1095 residue = min(residue, transfer_length); 1096 srb->resid = max(srb->resid, (int) residue); 1097 } 1098 } 1099 1100 /* based on the status code, we report good or bad */ 1101 switch (bcs->Status) { 1102 case US_BULK_STAT_OK: 1103 /* device babbled -- return fake sense data */ 1104 if (fake_sense) { 1105 memcpy(srb->sense_buffer, 1106 usb_stor_sense_invalidCDB, 1107 sizeof(usb_stor_sense_invalidCDB)); 1108 return USB_STOR_TRANSPORT_NO_SENSE; 1109 } 1110 1111 /* command good -- note that data could be short */ 1112 return USB_STOR_TRANSPORT_GOOD; 1113 1114 case US_BULK_STAT_FAIL: 1115 /* command failed */ 1116 return USB_STOR_TRANSPORT_FAILED; 1117 1118 case US_BULK_STAT_PHASE: 1119 /* phase error -- note that a transport reset will be 1120 * invoked by the invoke_transport() function 1121 */ 1122 return USB_STOR_TRANSPORT_ERROR; 1123 } 1124 1125 /* we should never get here, but if we do, we're in trouble */ 1126 return USB_STOR_TRANSPORT_ERROR; 1127 } 1128 1129 /*********************************************************************** 1130 * Reset routines 1131 ***********************************************************************/ 1132 1133 /* This is the common part of the device reset code. 1134 * 1135 * It's handy that every transport mechanism uses the control endpoint for 1136 * resets. 1137 * 1138 * Basically, we send a reset with a 5-second timeout, so we don't get 1139 * jammed attempting to do the reset. 1140 */ 1141 static int usb_stor_reset_common(struct us_data *us, 1142 u8 request, u8 requesttype, 1143 u16 value, u16 index, void *data, u16 size) 1144 { 1145 int result; 1146 int result2; 1147 1148 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1149 US_DEBUGP("No reset during disconnect\n"); 1150 return -EIO; 1151 } 1152 1153 result = usb_stor_control_msg(us, us->send_ctrl_pipe, 1154 request, requesttype, value, index, data, size, 1155 5*HZ); 1156 if (result < 0) { 1157 US_DEBUGP("Soft reset failed: %d\n", result); 1158 return result; 1159 } 1160 1161 /* Give the device some time to recover from the reset, 1162 * but don't delay disconnect processing. */ 1163 wait_event_interruptible_timeout(us->delay_wait, 1164 test_bit(US_FLIDX_DISCONNECTING, &us->flags), 1165 HZ*6); 1166 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1167 US_DEBUGP("Reset interrupted by disconnect\n"); 1168 return -EIO; 1169 } 1170 1171 US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n"); 1172 result = usb_stor_clear_halt(us, us->recv_bulk_pipe); 1173 1174 US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n"); 1175 result2 = usb_stor_clear_halt(us, us->send_bulk_pipe); 1176 1177 /* return a result code based on the result of the clear-halts */ 1178 if (result >= 0) 1179 result = result2; 1180 if (result < 0) 1181 US_DEBUGP("Soft reset failed\n"); 1182 else 1183 US_DEBUGP("Soft reset done\n"); 1184 return result; 1185 } 1186 1187 /* This issues a CB[I] Reset to the device in question 1188 */ 1189 #define CB_RESET_CMD_SIZE 12 1190 1191 int usb_stor_CB_reset(struct us_data *us) 1192 { 1193 US_DEBUGP("%s called\n", __FUNCTION__); 1194 1195 memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE); 1196 us->iobuf[0] = SEND_DIAGNOSTIC; 1197 us->iobuf[1] = 4; 1198 return usb_stor_reset_common(us, US_CBI_ADSC, 1199 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 1200 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE); 1201 } 1202 1203 /* This issues a Bulk-only Reset to the device in question, including 1204 * clearing the subsequent endpoint halts that may occur. 1205 */ 1206 int usb_stor_Bulk_reset(struct us_data *us) 1207 { 1208 US_DEBUGP("%s called\n", __FUNCTION__); 1209 1210 return usb_stor_reset_common(us, US_BULK_RESET_REQUEST, 1211 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 1212 0, us->ifnum, NULL, 0); 1213 } 1214 1215 /* Issue a USB port reset to the device. But don't do anything if 1216 * there's more than one interface in the device, so that other users 1217 * are not affected. */ 1218 int usb_stor_port_reset(struct us_data *us) 1219 { 1220 int result, rc; 1221 1222 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1223 result = -EIO; 1224 US_DEBUGP("No reset during disconnect\n"); 1225 } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) { 1226 result = -EBUSY; 1227 US_DEBUGP("Refusing to reset a multi-interface device\n"); 1228 } else { 1229 result = rc = 1230 usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); 1231 if (result < 0) { 1232 US_DEBUGP("unable to lock device for reset: %d\n", 1233 result); 1234 } else { 1235 result = usb_reset_device(us->pusb_dev); 1236 if (rc) 1237 usb_unlock_device(us->pusb_dev); 1238 US_DEBUGP("usb_reset_device returns %d\n", result); 1239 } 1240 } 1241 return result; 1242 } 1243