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 = us->sensebuf; 640 641 /* set the buffer length for transfer */ 642 old_request_bufflen = srb->request_bufflen; 643 srb->request_bufflen = US_SENSE_SIZE; 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 memcpy(srb->sense_buffer, us->sensebuf, US_SENSE_SIZE); 656 srb->resid = old_resid; 657 srb->request_buffer = old_request_buffer; 658 srb->request_bufflen = old_request_bufflen; 659 srb->use_sg = old_sg; 660 srb->sc_data_direction = old_sc_data_direction; 661 srb->cmd_len = old_cmd_len; 662 memcpy(srb->cmnd, old_cmnd, MAX_COMMAND_SIZE); 663 664 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) { 665 US_DEBUGP("-- auto-sense aborted\n"); 666 srb->result = DID_ABORT << 16; 667 goto Handle_Errors; 668 } 669 if (temp_result != USB_STOR_TRANSPORT_GOOD) { 670 US_DEBUGP("-- auto-sense failure\n"); 671 672 /* we skip the reset if this happens to be a 673 * multi-target device, since failure of an 674 * auto-sense is perfectly valid 675 */ 676 srb->result = DID_ERROR << 16; 677 if (!(us->flags & US_FL_SCM_MULT_TARG)) 678 goto Handle_Errors; 679 return; 680 } 681 682 US_DEBUGP("-- Result from auto-sense is %d\n", temp_result); 683 US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n", 684 srb->sense_buffer[0], 685 srb->sense_buffer[2] & 0xf, 686 srb->sense_buffer[12], 687 srb->sense_buffer[13]); 688 #ifdef CONFIG_USB_STORAGE_DEBUG 689 usb_stor_show_sense( 690 srb->sense_buffer[2] & 0xf, 691 srb->sense_buffer[12], 692 srb->sense_buffer[13]); 693 #endif 694 695 /* set the result so the higher layers expect this data */ 696 srb->result = SAM_STAT_CHECK_CONDITION; 697 698 /* If things are really okay, then let's show that. Zero 699 * out the sense buffer so the higher layers won't realize 700 * we did an unsolicited auto-sense. */ 701 if (result == USB_STOR_TRANSPORT_GOOD && 702 /* Filemark 0, ignore EOM, ILI 0, no sense */ 703 (srb->sense_buffer[2] & 0xaf) == 0 && 704 /* No ASC or ASCQ */ 705 srb->sense_buffer[12] == 0 && 706 srb->sense_buffer[13] == 0) { 707 srb->result = SAM_STAT_GOOD; 708 srb->sense_buffer[0] = 0x0; 709 } 710 } 711 712 /* Did we transfer less than the minimum amount required? */ 713 if (srb->result == SAM_STAT_GOOD && 714 srb->request_bufflen - srb->resid < srb->underflow) 715 srb->result = (DID_ERROR << 16) | (SUGGEST_RETRY << 24); 716 717 return; 718 719 /* Error and abort processing: try to resynchronize with the device 720 * by issuing a port reset. If that fails, try a class-specific 721 * device reset. */ 722 Handle_Errors: 723 724 /* Let the SCSI layer know we are doing a reset, set the 725 * RESETTING bit, and clear the ABORTING bit so that the reset 726 * may proceed. */ 727 scsi_lock(us_to_host(us)); 728 usb_stor_report_bus_reset(us); 729 set_bit(US_FLIDX_RESETTING, &us->flags); 730 clear_bit(US_FLIDX_ABORTING, &us->flags); 731 scsi_unlock(us_to_host(us)); 732 733 result = usb_stor_port_reset(us); 734 if (result < 0) { 735 scsi_lock(us_to_host(us)); 736 usb_stor_report_device_reset(us); 737 scsi_unlock(us_to_host(us)); 738 us->transport_reset(us); 739 } 740 clear_bit(US_FLIDX_RESETTING, &us->flags); 741 } 742 743 /* Stop the current URB transfer */ 744 void usb_stor_stop_transport(struct us_data *us) 745 { 746 US_DEBUGP("%s called\n", __FUNCTION__); 747 748 /* If the state machine is blocked waiting for an URB, 749 * let's wake it up. The test_and_clear_bit() call 750 * guarantees that if a URB has just been submitted, 751 * it won't be cancelled more than once. */ 752 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) { 753 US_DEBUGP("-- cancelling URB\n"); 754 usb_unlink_urb(us->current_urb); 755 } 756 757 /* If we are waiting for a scatter-gather operation, cancel it. */ 758 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) { 759 US_DEBUGP("-- cancelling sg request\n"); 760 usb_sg_cancel(&us->current_sg); 761 } 762 } 763 764 /* 765 * Control/Bulk/Interrupt transport 766 */ 767 768 int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us) 769 { 770 unsigned int transfer_length = srb->request_bufflen; 771 unsigned int pipe = 0; 772 int result; 773 774 /* COMMAND STAGE */ 775 /* let's send the command via the control pipe */ 776 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe, 777 US_CBI_ADSC, 778 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, 779 us->ifnum, srb->cmnd, srb->cmd_len); 780 781 /* check the return code for the command */ 782 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result); 783 784 /* if we stalled the command, it means command failed */ 785 if (result == USB_STOR_XFER_STALLED) { 786 return USB_STOR_TRANSPORT_FAILED; 787 } 788 789 /* Uh oh... serious problem here */ 790 if (result != USB_STOR_XFER_GOOD) { 791 return USB_STOR_TRANSPORT_ERROR; 792 } 793 794 /* DATA STAGE */ 795 /* transfer the data payload for this command, if one exists*/ 796 if (transfer_length) { 797 pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 798 us->recv_bulk_pipe : us->send_bulk_pipe; 799 result = usb_stor_bulk_transfer_sg(us, pipe, 800 srb->request_buffer, transfer_length, 801 srb->use_sg, &srb->resid); 802 US_DEBUGP("CBI data stage result is 0x%x\n", result); 803 804 /* if we stalled the data transfer it means command failed */ 805 if (result == USB_STOR_XFER_STALLED) 806 return USB_STOR_TRANSPORT_FAILED; 807 if (result > USB_STOR_XFER_STALLED) 808 return USB_STOR_TRANSPORT_ERROR; 809 } 810 811 /* STATUS STAGE */ 812 result = usb_stor_intr_transfer(us, us->iobuf, 2); 813 US_DEBUGP("Got interrupt data (0x%x, 0x%x)\n", 814 us->iobuf[0], us->iobuf[1]); 815 if (result != USB_STOR_XFER_GOOD) 816 return USB_STOR_TRANSPORT_ERROR; 817 818 /* UFI gives us ASC and ASCQ, like a request sense 819 * 820 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI 821 * devices, so we ignore the information for those commands. Note 822 * that this means we could be ignoring a real error on these 823 * commands, but that can't be helped. 824 */ 825 if (us->subclass == US_SC_UFI) { 826 if (srb->cmnd[0] == REQUEST_SENSE || 827 srb->cmnd[0] == INQUIRY) 828 return USB_STOR_TRANSPORT_GOOD; 829 if (us->iobuf[0]) 830 goto Failed; 831 return USB_STOR_TRANSPORT_GOOD; 832 } 833 834 /* If not UFI, we interpret the data as a result code 835 * The first byte should always be a 0x0. 836 * 837 * Some bogus devices don't follow that rule. They stuff the ASC 838 * into the first byte -- so if it's non-zero, call it a failure. 839 */ 840 if (us->iobuf[0]) { 841 US_DEBUGP("CBI IRQ data showed reserved bType 0x%x\n", 842 us->iobuf[0]); 843 goto Failed; 844 845 } 846 847 /* The second byte & 0x0F should be 0x0 for good, otherwise error */ 848 switch (us->iobuf[1] & 0x0F) { 849 case 0x00: 850 return USB_STOR_TRANSPORT_GOOD; 851 case 0x01: 852 goto Failed; 853 } 854 return USB_STOR_TRANSPORT_ERROR; 855 856 /* the CBI spec requires that the bulk pipe must be cleared 857 * following any data-in/out command failure (section 2.4.3.1.3) 858 */ 859 Failed: 860 if (pipe) 861 usb_stor_clear_halt(us, pipe); 862 return USB_STOR_TRANSPORT_FAILED; 863 } 864 865 /* 866 * Control/Bulk transport 867 */ 868 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us) 869 { 870 unsigned int transfer_length = srb->request_bufflen; 871 int result; 872 873 /* COMMAND STAGE */ 874 /* let's send the command via the control pipe */ 875 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe, 876 US_CBI_ADSC, 877 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, 878 us->ifnum, srb->cmnd, srb->cmd_len); 879 880 /* check the return code for the command */ 881 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result); 882 883 /* if we stalled the command, it means command failed */ 884 if (result == USB_STOR_XFER_STALLED) { 885 return USB_STOR_TRANSPORT_FAILED; 886 } 887 888 /* Uh oh... serious problem here */ 889 if (result != USB_STOR_XFER_GOOD) { 890 return USB_STOR_TRANSPORT_ERROR; 891 } 892 893 /* DATA STAGE */ 894 /* transfer the data payload for this command, if one exists*/ 895 if (transfer_length) { 896 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 897 us->recv_bulk_pipe : us->send_bulk_pipe; 898 result = usb_stor_bulk_transfer_sg(us, pipe, 899 srb->request_buffer, transfer_length, 900 srb->use_sg, &srb->resid); 901 US_DEBUGP("CB data stage result is 0x%x\n", result); 902 903 /* if we stalled the data transfer it means command failed */ 904 if (result == USB_STOR_XFER_STALLED) 905 return USB_STOR_TRANSPORT_FAILED; 906 if (result > USB_STOR_XFER_STALLED) 907 return USB_STOR_TRANSPORT_ERROR; 908 } 909 910 /* STATUS STAGE */ 911 /* NOTE: CB does not have a status stage. Silly, I know. So 912 * we have to catch this at a higher level. 913 */ 914 return USB_STOR_TRANSPORT_GOOD; 915 } 916 917 /* 918 * Bulk only transport 919 */ 920 921 /* Determine what the maximum LUN supported is */ 922 int usb_stor_Bulk_max_lun(struct us_data *us) 923 { 924 int result; 925 926 /* issue the command */ 927 us->iobuf[0] = 0; 928 result = usb_stor_control_msg(us, us->recv_ctrl_pipe, 929 US_BULK_GET_MAX_LUN, 930 USB_DIR_IN | USB_TYPE_CLASS | 931 USB_RECIP_INTERFACE, 932 0, us->ifnum, us->iobuf, 1, HZ); 933 934 US_DEBUGP("GetMaxLUN command result is %d, data is %d\n", 935 result, us->iobuf[0]); 936 937 /* if we have a successful request, return the result */ 938 if (result > 0) 939 return us->iobuf[0]; 940 941 /* 942 * Some devices (i.e. Iomega Zip100) need this -- apparently 943 * the bulk pipes get STALLed when the GetMaxLUN request is 944 * processed. This is, in theory, harmless to all other devices 945 * (regardless of if they stall or not). 946 */ 947 if (result == -EPIPE) { 948 usb_stor_clear_halt(us, us->recv_bulk_pipe); 949 usb_stor_clear_halt(us, us->send_bulk_pipe); 950 } 951 952 /* 953 * Some devices don't like GetMaxLUN. They may STALL the control 954 * pipe, they may return a zero-length result, they may do nothing at 955 * all and timeout, or they may fail in even more bizarrely creative 956 * ways. In these cases the best approach is to use the default 957 * value: only one LUN. 958 */ 959 return 0; 960 } 961 962 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us) 963 { 964 struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf; 965 struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf; 966 unsigned int transfer_length = srb->request_bufflen; 967 unsigned int residue; 968 int result; 969 int fake_sense = 0; 970 unsigned int cswlen; 971 unsigned int cbwlen = US_BULK_CB_WRAP_LEN; 972 973 /* Take care of BULK32 devices; set extra byte to 0 */ 974 if ( unlikely(us->flags & US_FL_BULK32)) { 975 cbwlen = 32; 976 us->iobuf[31] = 0; 977 } 978 979 /* set up the command wrapper */ 980 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN); 981 bcb->DataTransferLength = cpu_to_le32(transfer_length); 982 bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0; 983 bcb->Tag = ++us->tag; 984 bcb->Lun = srb->device->lun; 985 if (us->flags & US_FL_SCM_MULT_TARG) 986 bcb->Lun |= srb->device->id << 4; 987 bcb->Length = srb->cmd_len; 988 989 /* copy the command payload */ 990 memset(bcb->CDB, 0, sizeof(bcb->CDB)); 991 memcpy(bcb->CDB, srb->cmnd, bcb->Length); 992 993 /* send it to out endpoint */ 994 US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n", 995 le32_to_cpu(bcb->Signature), bcb->Tag, 996 le32_to_cpu(bcb->DataTransferLength), bcb->Flags, 997 (bcb->Lun >> 4), (bcb->Lun & 0x0F), 998 bcb->Length); 999 result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe, 1000 bcb, cbwlen, NULL); 1001 US_DEBUGP("Bulk command transfer result=%d\n", result); 1002 if (result != USB_STOR_XFER_GOOD) 1003 return USB_STOR_TRANSPORT_ERROR; 1004 1005 /* DATA STAGE */ 1006 /* send/receive data payload, if there is any */ 1007 1008 /* Some USB-IDE converter chips need a 100us delay between the 1009 * command phase and the data phase. Some devices need a little 1010 * more than that, probably because of clock rate inaccuracies. */ 1011 if (unlikely(us->flags & US_FL_GO_SLOW)) 1012 udelay(125); 1013 1014 if (transfer_length) { 1015 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 1016 us->recv_bulk_pipe : us->send_bulk_pipe; 1017 result = usb_stor_bulk_transfer_sg(us, pipe, 1018 srb->request_buffer, transfer_length, 1019 srb->use_sg, &srb->resid); 1020 US_DEBUGP("Bulk data transfer result 0x%x\n", result); 1021 if (result == USB_STOR_XFER_ERROR) 1022 return USB_STOR_TRANSPORT_ERROR; 1023 1024 /* If the device tried to send back more data than the 1025 * amount requested, the spec requires us to transfer 1026 * the CSW anyway. Since there's no point retrying the 1027 * the command, we'll return fake sense data indicating 1028 * Illegal Request, Invalid Field in CDB. 1029 */ 1030 if (result == USB_STOR_XFER_LONG) 1031 fake_sense = 1; 1032 } 1033 1034 /* See flow chart on pg 15 of the Bulk Only Transport spec for 1035 * an explanation of how this code works. 1036 */ 1037 1038 /* get CSW for device status */ 1039 US_DEBUGP("Attempting to get CSW...\n"); 1040 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 1041 bcs, US_BULK_CS_WRAP_LEN, &cswlen); 1042 1043 /* Some broken devices add unnecessary zero-length packets to the 1044 * end of their data transfers. Such packets show up as 0-length 1045 * CSWs. If we encounter such a thing, try to read the CSW again. 1046 */ 1047 if (result == USB_STOR_XFER_SHORT && cswlen == 0) { 1048 US_DEBUGP("Received 0-length CSW; retrying...\n"); 1049 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 1050 bcs, US_BULK_CS_WRAP_LEN, &cswlen); 1051 } 1052 1053 /* did the attempt to read the CSW fail? */ 1054 if (result == USB_STOR_XFER_STALLED) { 1055 1056 /* get the status again */ 1057 US_DEBUGP("Attempting to get CSW (2nd try)...\n"); 1058 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 1059 bcs, US_BULK_CS_WRAP_LEN, NULL); 1060 } 1061 1062 /* if we still have a failure at this point, we're in trouble */ 1063 US_DEBUGP("Bulk status result = %d\n", result); 1064 if (result != USB_STOR_XFER_GOOD) 1065 return USB_STOR_TRANSPORT_ERROR; 1066 1067 /* check bulk status */ 1068 residue = le32_to_cpu(bcs->Residue); 1069 US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n", 1070 le32_to_cpu(bcs->Signature), bcs->Tag, 1071 residue, bcs->Status); 1072 if (bcs->Tag != us->tag || bcs->Status > US_BULK_STAT_PHASE) { 1073 US_DEBUGP("Bulk logical error\n"); 1074 return USB_STOR_TRANSPORT_ERROR; 1075 } 1076 1077 /* Some broken devices report odd signatures, so we do not check them 1078 * for validity against the spec. We store the first one we see, 1079 * and check subsequent transfers for validity against this signature. 1080 */ 1081 if (!us->bcs_signature) { 1082 us->bcs_signature = bcs->Signature; 1083 if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN)) 1084 US_DEBUGP("Learnt BCS signature 0x%08X\n", 1085 le32_to_cpu(us->bcs_signature)); 1086 } else if (bcs->Signature != us->bcs_signature) { 1087 US_DEBUGP("Signature mismatch: got %08X, expecting %08X\n", 1088 le32_to_cpu(bcs->Signature), 1089 le32_to_cpu(us->bcs_signature)); 1090 return USB_STOR_TRANSPORT_ERROR; 1091 } 1092 1093 /* try to compute the actual residue, based on how much data 1094 * was really transferred and what the device tells us */ 1095 if (residue) { 1096 if (!(us->flags & US_FL_IGNORE_RESIDUE)) { 1097 residue = min(residue, transfer_length); 1098 srb->resid = max(srb->resid, (int) residue); 1099 } 1100 } 1101 1102 /* based on the status code, we report good or bad */ 1103 switch (bcs->Status) { 1104 case US_BULK_STAT_OK: 1105 /* device babbled -- return fake sense data */ 1106 if (fake_sense) { 1107 memcpy(srb->sense_buffer, 1108 usb_stor_sense_invalidCDB, 1109 sizeof(usb_stor_sense_invalidCDB)); 1110 return USB_STOR_TRANSPORT_NO_SENSE; 1111 } 1112 1113 /* command good -- note that data could be short */ 1114 return USB_STOR_TRANSPORT_GOOD; 1115 1116 case US_BULK_STAT_FAIL: 1117 /* command failed */ 1118 return USB_STOR_TRANSPORT_FAILED; 1119 1120 case US_BULK_STAT_PHASE: 1121 /* phase error -- note that a transport reset will be 1122 * invoked by the invoke_transport() function 1123 */ 1124 return USB_STOR_TRANSPORT_ERROR; 1125 } 1126 1127 /* we should never get here, but if we do, we're in trouble */ 1128 return USB_STOR_TRANSPORT_ERROR; 1129 } 1130 1131 /*********************************************************************** 1132 * Reset routines 1133 ***********************************************************************/ 1134 1135 /* This is the common part of the device reset code. 1136 * 1137 * It's handy that every transport mechanism uses the control endpoint for 1138 * resets. 1139 * 1140 * Basically, we send a reset with a 5-second timeout, so we don't get 1141 * jammed attempting to do the reset. 1142 */ 1143 static int usb_stor_reset_common(struct us_data *us, 1144 u8 request, u8 requesttype, 1145 u16 value, u16 index, void *data, u16 size) 1146 { 1147 int result; 1148 int result2; 1149 1150 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1151 US_DEBUGP("No reset during disconnect\n"); 1152 return -EIO; 1153 } 1154 1155 result = usb_stor_control_msg(us, us->send_ctrl_pipe, 1156 request, requesttype, value, index, data, size, 1157 5*HZ); 1158 if (result < 0) { 1159 US_DEBUGP("Soft reset failed: %d\n", result); 1160 return result; 1161 } 1162 1163 /* Give the device some time to recover from the reset, 1164 * but don't delay disconnect processing. */ 1165 wait_event_interruptible_timeout(us->delay_wait, 1166 test_bit(US_FLIDX_DISCONNECTING, &us->flags), 1167 HZ*6); 1168 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1169 US_DEBUGP("Reset interrupted by disconnect\n"); 1170 return -EIO; 1171 } 1172 1173 US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n"); 1174 result = usb_stor_clear_halt(us, us->recv_bulk_pipe); 1175 1176 US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n"); 1177 result2 = usb_stor_clear_halt(us, us->send_bulk_pipe); 1178 1179 /* return a result code based on the result of the clear-halts */ 1180 if (result >= 0) 1181 result = result2; 1182 if (result < 0) 1183 US_DEBUGP("Soft reset failed\n"); 1184 else 1185 US_DEBUGP("Soft reset done\n"); 1186 return result; 1187 } 1188 1189 /* This issues a CB[I] Reset to the device in question 1190 */ 1191 #define CB_RESET_CMD_SIZE 12 1192 1193 int usb_stor_CB_reset(struct us_data *us) 1194 { 1195 US_DEBUGP("%s called\n", __FUNCTION__); 1196 1197 memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE); 1198 us->iobuf[0] = SEND_DIAGNOSTIC; 1199 us->iobuf[1] = 4; 1200 return usb_stor_reset_common(us, US_CBI_ADSC, 1201 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 1202 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE); 1203 } 1204 1205 /* This issues a Bulk-only Reset to the device in question, including 1206 * clearing the subsequent endpoint halts that may occur. 1207 */ 1208 int usb_stor_Bulk_reset(struct us_data *us) 1209 { 1210 US_DEBUGP("%s called\n", __FUNCTION__); 1211 1212 return usb_stor_reset_common(us, US_BULK_RESET_REQUEST, 1213 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 1214 0, us->ifnum, NULL, 0); 1215 } 1216 1217 /* Issue a USB port reset to the device. But don't do anything if 1218 * there's more than one interface in the device, so that other users 1219 * are not affected. */ 1220 int usb_stor_port_reset(struct us_data *us) 1221 { 1222 int result, rc; 1223 1224 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1225 result = -EIO; 1226 US_DEBUGP("No reset during disconnect\n"); 1227 } else if (us->pusb_dev->actconfig->desc.bNumInterfaces != 1) { 1228 result = -EBUSY; 1229 US_DEBUGP("Refusing to reset a multi-interface device\n"); 1230 } else { 1231 result = rc = 1232 usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); 1233 if (result < 0) { 1234 US_DEBUGP("unable to lock device for reset: %d\n", 1235 result); 1236 } else { 1237 result = usb_reset_device(us->pusb_dev); 1238 if (rc) 1239 usb_unlock_device(us->pusb_dev); 1240 US_DEBUGP("usb_reset_device returns %d\n", result); 1241 } 1242 } 1243 return result; 1244 } 1245