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/sched.h> 49 #include <linux/errno.h> 50 #include <linux/slab.h> 51 52 #include <scsi/scsi.h> 53 #include <scsi/scsi_eh.h> 54 #include <scsi/scsi_device.h> 55 56 #include "usb.h" 57 #include "transport.h" 58 #include "protocol.h" 59 #include "scsiglue.h" 60 #include "debug.h" 61 62 63 /*********************************************************************** 64 * Data transfer routines 65 ***********************************************************************/ 66 67 /* 68 * This is subtle, so pay attention: 69 * --------------------------------- 70 * We're very concerned about races with a command abort. Hanging this code 71 * is a sure fire way to hang the kernel. (Note that this discussion applies 72 * only to transactions resulting from a scsi queued-command, since only 73 * these transactions are subject to a scsi abort. Other transactions, such 74 * as those occurring during device-specific initialization, must be handled 75 * by a separate code path.) 76 * 77 * The abort function (usb_storage_command_abort() in scsiglue.c) first 78 * sets the machine state and the ABORTING bit in us->flags to prevent 79 * new URBs from being submitted. It then calls usb_stor_stop_transport() 80 * below, which atomically tests-and-clears the URB_ACTIVE bit in us->flags 81 * to see if the current_urb needs to be stopped. Likewise, the SG_ACTIVE 82 * bit is tested to see if the current_sg scatter-gather request needs to be 83 * stopped. The timeout callback routine does much the same thing. 84 * 85 * When a disconnect occurs, the DISCONNECTING bit in us->flags is set to 86 * prevent new URBs from being submitted, and usb_stor_stop_transport() is 87 * called to stop any ongoing requests. 88 * 89 * The submit function first verifies that the submitting is allowed 90 * (neither ABORTING nor DISCONNECTING bits are set) and that the submit 91 * completes without errors, and only then sets the URB_ACTIVE bit. This 92 * prevents the stop_transport() function from trying to cancel the URB 93 * while the submit call is underway. Next, the submit function must test 94 * the flags to see if an abort or disconnect occurred during the submission 95 * or before the URB_ACTIVE bit was set. If so, it's essential to cancel 96 * the URB if it hasn't been cancelled already (i.e., if the URB_ACTIVE bit 97 * is still set). Either way, the function must then wait for the URB to 98 * finish. Note that the URB can still be in progress even after a call to 99 * usb_unlink_urb() returns. 100 * 101 * The idea is that (1) once the ABORTING or DISCONNECTING bit is set, 102 * either the stop_transport() function or the submitting function 103 * is guaranteed to call usb_unlink_urb() for an active URB, 104 * and (2) test_and_clear_bit() prevents usb_unlink_urb() from being 105 * called more than once or from being called during usb_submit_urb(). 106 */ 107 108 /* This is the completion handler which will wake us up when an URB 109 * completes. 110 */ 111 static void usb_stor_blocking_completion(struct urb *urb) 112 { 113 struct completion *urb_done_ptr = (struct completion *)urb->context; 114 115 complete(urb_done_ptr); 116 } 117 118 /* This is the common part of the URB message submission code 119 * 120 * All URBs from the usb-storage driver involved in handling a queued scsi 121 * command _must_ pass through this function (or something like it) for the 122 * abort mechanisms to work properly. 123 */ 124 static int usb_stor_msg_common(struct us_data *us, int timeout) 125 { 126 struct completion urb_done; 127 long timeleft; 128 int status; 129 130 /* don't submit URBs during abort/disconnect processing */ 131 if (us->flags & ABORTING_OR_DISCONNECTING) 132 return -EIO; 133 134 /* set up data structures for the wakeup system */ 135 init_completion(&urb_done); 136 137 /* fill the common fields in the URB */ 138 us->current_urb->context = &urb_done; 139 us->current_urb->actual_length = 0; 140 us->current_urb->error_count = 0; 141 us->current_urb->status = 0; 142 143 /* we assume that if transfer_buffer isn't us->iobuf then it 144 * hasn't been mapped for DMA. Yes, this is clunky, but it's 145 * easier than always having the caller tell us whether the 146 * transfer buffer has already been mapped. */ 147 us->current_urb->transfer_flags = URB_NO_SETUP_DMA_MAP; 148 if (us->current_urb->transfer_buffer == us->iobuf) 149 us->current_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP; 150 us->current_urb->transfer_dma = us->iobuf_dma; 151 us->current_urb->setup_dma = us->cr_dma; 152 153 /* submit the URB */ 154 status = usb_submit_urb(us->current_urb, GFP_NOIO); 155 if (status) { 156 /* something went wrong */ 157 return status; 158 } 159 160 /* since the URB has been submitted successfully, it's now okay 161 * to cancel it */ 162 set_bit(US_FLIDX_URB_ACTIVE, &us->flags); 163 164 /* did an abort/disconnect occur during the submission? */ 165 if (us->flags & ABORTING_OR_DISCONNECTING) { 166 167 /* cancel the URB, if it hasn't been cancelled already */ 168 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) { 169 US_DEBUGP("-- cancelling URB\n"); 170 usb_unlink_urb(us->current_urb); 171 } 172 } 173 174 /* wait for the completion of the URB */ 175 timeleft = wait_for_completion_interruptible_timeout( 176 &urb_done, timeout ? : MAX_SCHEDULE_TIMEOUT); 177 178 clear_bit(US_FLIDX_URB_ACTIVE, &us->flags); 179 180 if (timeleft <= 0) { 181 US_DEBUGP("%s -- cancelling URB\n", 182 timeleft == 0 ? "Timeout" : "Signal"); 183 usb_kill_urb(us->current_urb); 184 } 185 186 /* return the URB status */ 187 return us->current_urb->status; 188 } 189 190 /* 191 * Transfer one control message, with timeouts, and allowing early 192 * termination. Return codes are usual -Exxx, *not* USB_STOR_XFER_xxx. 193 */ 194 int usb_stor_control_msg(struct us_data *us, unsigned int pipe, 195 u8 request, u8 requesttype, u16 value, u16 index, 196 void *data, u16 size, int timeout) 197 { 198 int status; 199 200 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n", 201 __FUNCTION__, request, requesttype, 202 value, index, size); 203 204 /* fill in the devrequest structure */ 205 us->cr->bRequestType = requesttype; 206 us->cr->bRequest = request; 207 us->cr->wValue = cpu_to_le16(value); 208 us->cr->wIndex = cpu_to_le16(index); 209 us->cr->wLength = cpu_to_le16(size); 210 211 /* fill and submit the URB */ 212 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe, 213 (unsigned char*) us->cr, data, size, 214 usb_stor_blocking_completion, NULL); 215 status = usb_stor_msg_common(us, timeout); 216 217 /* return the actual length of the data transferred if no error */ 218 if (status == 0) 219 status = us->current_urb->actual_length; 220 return status; 221 } 222 223 /* This is a version of usb_clear_halt() that allows early termination and 224 * doesn't read the status from the device -- this is because some devices 225 * crash their internal firmware when the status is requested after a halt. 226 * 227 * A definitive list of these 'bad' devices is too difficult to maintain or 228 * make complete enough to be useful. This problem was first observed on the 229 * Hagiwara FlashGate DUAL unit. However, bus traces reveal that neither 230 * MacOS nor Windows checks the status after clearing a halt. 231 * 232 * Since many vendors in this space limit their testing to interoperability 233 * with these two OSes, specification violations like this one are common. 234 */ 235 int usb_stor_clear_halt(struct us_data *us, unsigned int pipe) 236 { 237 int result; 238 int endp = usb_pipeendpoint(pipe); 239 240 if (usb_pipein (pipe)) 241 endp |= USB_DIR_IN; 242 243 result = usb_stor_control_msg(us, us->send_ctrl_pipe, 244 USB_REQ_CLEAR_FEATURE, USB_RECIP_ENDPOINT, 245 USB_ENDPOINT_HALT, endp, 246 NULL, 0, 3*HZ); 247 248 /* reset the endpoint toggle */ 249 if (result >= 0) 250 usb_settoggle(us->pusb_dev, usb_pipeendpoint(pipe), 251 usb_pipeout(pipe), 0); 252 253 US_DEBUGP("%s: result = %d\n", __FUNCTION__, result); 254 return result; 255 } 256 257 258 /* 259 * Interpret the results of a URB transfer 260 * 261 * This function prints appropriate debugging messages, clears halts on 262 * non-control endpoints, and translates the status to the corresponding 263 * USB_STOR_XFER_xxx return code. 264 */ 265 static int interpret_urb_result(struct us_data *us, unsigned int pipe, 266 unsigned int length, int result, unsigned int partial) 267 { 268 US_DEBUGP("Status code %d; transferred %u/%u\n", 269 result, partial, length); 270 switch (result) { 271 272 /* no error code; did we send all the data? */ 273 case 0: 274 if (partial != length) { 275 US_DEBUGP("-- short transfer\n"); 276 return USB_STOR_XFER_SHORT; 277 } 278 279 US_DEBUGP("-- transfer complete\n"); 280 return USB_STOR_XFER_GOOD; 281 282 /* stalled */ 283 case -EPIPE: 284 /* for control endpoints, (used by CB[I]) a stall indicates 285 * a failed command */ 286 if (usb_pipecontrol(pipe)) { 287 US_DEBUGP("-- stall on control pipe\n"); 288 return USB_STOR_XFER_STALLED; 289 } 290 291 /* for other sorts of endpoint, clear the stall */ 292 US_DEBUGP("clearing endpoint halt for pipe 0x%x\n", pipe); 293 if (usb_stor_clear_halt(us, pipe) < 0) 294 return USB_STOR_XFER_ERROR; 295 return USB_STOR_XFER_STALLED; 296 297 /* babble - the device tried to send more than we wanted to read */ 298 case -EOVERFLOW: 299 US_DEBUGP("-- babble\n"); 300 return USB_STOR_XFER_LONG; 301 302 /* the transfer was cancelled by abort, disconnect, or timeout */ 303 case -ECONNRESET: 304 US_DEBUGP("-- transfer cancelled\n"); 305 return USB_STOR_XFER_ERROR; 306 307 /* short scatter-gather read transfer */ 308 case -EREMOTEIO: 309 US_DEBUGP("-- short read transfer\n"); 310 return USB_STOR_XFER_SHORT; 311 312 /* abort or disconnect in progress */ 313 case -EIO: 314 US_DEBUGP("-- abort or disconnect in progress\n"); 315 return USB_STOR_XFER_ERROR; 316 317 /* the catch-all error case */ 318 default: 319 US_DEBUGP("-- unknown error\n"); 320 return USB_STOR_XFER_ERROR; 321 } 322 } 323 324 /* 325 * Transfer one control message, without timeouts, but allowing early 326 * termination. Return codes are USB_STOR_XFER_xxx. 327 */ 328 int usb_stor_ctrl_transfer(struct us_data *us, unsigned int pipe, 329 u8 request, u8 requesttype, u16 value, u16 index, 330 void *data, u16 size) 331 { 332 int result; 333 334 US_DEBUGP("%s: rq=%02x rqtype=%02x value=%04x index=%02x len=%u\n", 335 __FUNCTION__, request, requesttype, 336 value, index, size); 337 338 /* fill in the devrequest structure */ 339 us->cr->bRequestType = requesttype; 340 us->cr->bRequest = request; 341 us->cr->wValue = cpu_to_le16(value); 342 us->cr->wIndex = cpu_to_le16(index); 343 us->cr->wLength = cpu_to_le16(size); 344 345 /* fill and submit the URB */ 346 usb_fill_control_urb(us->current_urb, us->pusb_dev, pipe, 347 (unsigned char*) us->cr, data, size, 348 usb_stor_blocking_completion, NULL); 349 result = usb_stor_msg_common(us, 0); 350 351 return interpret_urb_result(us, pipe, size, result, 352 us->current_urb->actual_length); 353 } 354 355 /* 356 * Receive one interrupt buffer, without timeouts, but allowing early 357 * termination. Return codes are USB_STOR_XFER_xxx. 358 * 359 * This routine always uses us->recv_intr_pipe as the pipe and 360 * us->ep_bInterval as the interrupt interval. 361 */ 362 static int usb_stor_intr_transfer(struct us_data *us, void *buf, 363 unsigned int length) 364 { 365 int result; 366 unsigned int pipe = us->recv_intr_pipe; 367 unsigned int maxp; 368 369 US_DEBUGP("%s: xfer %u bytes\n", __FUNCTION__, length); 370 371 /* calculate the max packet size */ 372 maxp = usb_maxpacket(us->pusb_dev, pipe, usb_pipeout(pipe)); 373 if (maxp > length) 374 maxp = length; 375 376 /* fill and submit the URB */ 377 usb_fill_int_urb(us->current_urb, us->pusb_dev, pipe, buf, 378 maxp, usb_stor_blocking_completion, NULL, 379 us->ep_bInterval); 380 result = usb_stor_msg_common(us, 0); 381 382 return interpret_urb_result(us, pipe, length, result, 383 us->current_urb->actual_length); 384 } 385 386 /* 387 * Transfer one buffer via bulk pipe, without timeouts, but allowing early 388 * termination. Return codes are USB_STOR_XFER_xxx. If the bulk pipe 389 * stalls during the transfer, the halt is automatically cleared. 390 */ 391 int usb_stor_bulk_transfer_buf(struct us_data *us, unsigned int pipe, 392 void *buf, unsigned int length, unsigned int *act_len) 393 { 394 int result; 395 396 US_DEBUGP("%s: xfer %u bytes\n", __FUNCTION__, length); 397 398 /* fill and submit the URB */ 399 usb_fill_bulk_urb(us->current_urb, us->pusb_dev, pipe, buf, length, 400 usb_stor_blocking_completion, NULL); 401 result = usb_stor_msg_common(us, 0); 402 403 /* store the actual length of the data transferred */ 404 if (act_len) 405 *act_len = us->current_urb->actual_length; 406 return interpret_urb_result(us, pipe, length, result, 407 us->current_urb->actual_length); 408 } 409 410 /* 411 * Transfer a scatter-gather list via bulk transfer 412 * 413 * This function does basically the same thing as usb_stor_bulk_transfer_buf() 414 * above, but it uses the usbcore scatter-gather library. 415 */ 416 static int usb_stor_bulk_transfer_sglist(struct us_data *us, unsigned int pipe, 417 struct scatterlist *sg, int num_sg, unsigned int length, 418 unsigned int *act_len) 419 { 420 int result; 421 422 /* don't submit s-g requests during abort/disconnect processing */ 423 if (us->flags & ABORTING_OR_DISCONNECTING) 424 return USB_STOR_XFER_ERROR; 425 426 /* initialize the scatter-gather request block */ 427 US_DEBUGP("%s: xfer %u bytes, %d entries\n", __FUNCTION__, 428 length, num_sg); 429 result = usb_sg_init(&us->current_sg, us->pusb_dev, pipe, 0, 430 sg, num_sg, length, GFP_NOIO); 431 if (result) { 432 US_DEBUGP("usb_sg_init returned %d\n", result); 433 return USB_STOR_XFER_ERROR; 434 } 435 436 /* since the block has been initialized successfully, it's now 437 * okay to cancel it */ 438 set_bit(US_FLIDX_SG_ACTIVE, &us->flags); 439 440 /* did an abort/disconnect occur during the submission? */ 441 if (us->flags & ABORTING_OR_DISCONNECTING) { 442 443 /* cancel the request, if it hasn't been cancelled already */ 444 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) { 445 US_DEBUGP("-- cancelling sg request\n"); 446 usb_sg_cancel(&us->current_sg); 447 } 448 } 449 450 /* wait for the completion of the transfer */ 451 usb_sg_wait(&us->current_sg); 452 clear_bit(US_FLIDX_SG_ACTIVE, &us->flags); 453 454 result = us->current_sg.status; 455 if (act_len) 456 *act_len = us->current_sg.bytes; 457 return interpret_urb_result(us, pipe, length, result, 458 us->current_sg.bytes); 459 } 460 461 /* 462 * Transfer an entire SCSI command's worth of data payload over the bulk 463 * pipe. 464 * 465 * Note that this uses usb_stor_bulk_transfer_buf() and 466 * usb_stor_bulk_transfer_sglist() to achieve its goals -- 467 * this function simply determines whether we're going to use 468 * scatter-gather or not, and acts appropriately. 469 */ 470 int usb_stor_bulk_transfer_sg(struct us_data* us, unsigned int pipe, 471 void *buf, unsigned int length_left, int use_sg, int *residual) 472 { 473 int result; 474 unsigned int partial; 475 476 /* are we scatter-gathering? */ 477 if (use_sg) { 478 /* use the usb core scatter-gather primitives */ 479 result = usb_stor_bulk_transfer_sglist(us, pipe, 480 (struct scatterlist *) buf, use_sg, 481 length_left, &partial); 482 length_left -= partial; 483 } else { 484 /* no scatter-gather, just make the request */ 485 result = usb_stor_bulk_transfer_buf(us, pipe, buf, 486 length_left, &partial); 487 length_left -= partial; 488 } 489 490 /* store the residual and return the error code */ 491 if (residual) 492 *residual = length_left; 493 return result; 494 } 495 496 /*********************************************************************** 497 * Transport routines 498 ***********************************************************************/ 499 500 /* Invoke the transport and basic error-handling/recovery methods 501 * 502 * This is used by the protocol layers to actually send the message to 503 * the device and receive the response. 504 */ 505 void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us) 506 { 507 int need_auto_sense; 508 int result; 509 510 /* send the command to the transport layer */ 511 srb->resid = 0; 512 result = us->transport(srb, us); 513 514 /* if the command gets aborted by the higher layers, we need to 515 * short-circuit all other processing 516 */ 517 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) { 518 US_DEBUGP("-- command was aborted\n"); 519 srb->result = DID_ABORT << 16; 520 goto Handle_Errors; 521 } 522 523 /* if there is a transport error, reset and don't auto-sense */ 524 if (result == USB_STOR_TRANSPORT_ERROR) { 525 US_DEBUGP("-- transport indicates error, resetting\n"); 526 srb->result = DID_ERROR << 16; 527 goto Handle_Errors; 528 } 529 530 /* if the transport provided its own sense data, don't auto-sense */ 531 if (result == USB_STOR_TRANSPORT_NO_SENSE) { 532 srb->result = SAM_STAT_CHECK_CONDITION; 533 return; 534 } 535 536 srb->result = SAM_STAT_GOOD; 537 538 /* Determine if we need to auto-sense 539 * 540 * I normally don't use a flag like this, but it's almost impossible 541 * to understand what's going on here if I don't. 542 */ 543 need_auto_sense = 0; 544 545 /* 546 * If we're running the CB transport, which is incapable 547 * of determining status on its own, we will auto-sense 548 * unless the operation involved a data-in transfer. Devices 549 * can signal most data-in errors by stalling the bulk-in pipe. 550 */ 551 if ((us->protocol == US_PR_CB || us->protocol == US_PR_DPCM_USB) && 552 srb->sc_data_direction != DMA_FROM_DEVICE) { 553 US_DEBUGP("-- CB transport device requiring auto-sense\n"); 554 need_auto_sense = 1; 555 } 556 557 /* 558 * If we have a failure, we're going to do a REQUEST_SENSE 559 * automatically. Note that we differentiate between a command 560 * "failure" and an "error" in the transport mechanism. 561 */ 562 if (result == USB_STOR_TRANSPORT_FAILED) { 563 US_DEBUGP("-- transport indicates command failure\n"); 564 need_auto_sense = 1; 565 } 566 567 /* 568 * A short transfer on a command where we don't expect it 569 * is unusual, but it doesn't mean we need to auto-sense. 570 */ 571 if ((srb->resid > 0) && 572 !((srb->cmnd[0] == REQUEST_SENSE) || 573 (srb->cmnd[0] == INQUIRY) || 574 (srb->cmnd[0] == MODE_SENSE) || 575 (srb->cmnd[0] == LOG_SENSE) || 576 (srb->cmnd[0] == MODE_SENSE_10))) { 577 US_DEBUGP("-- unexpectedly short transfer\n"); 578 } 579 580 /* Now, if we need to do the auto-sense, let's do it */ 581 if (need_auto_sense) { 582 int temp_result; 583 struct scsi_eh_save ses; 584 585 US_DEBUGP("Issuing auto-REQUEST_SENSE\n"); 586 587 scsi_eh_prep_cmnd(srb, &ses, NULL, 0, US_SENSE_SIZE); 588 589 /* FIXME: we must do the protocol translation here */ 590 if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI) 591 srb->cmd_len = 6; 592 else 593 srb->cmd_len = 12; 594 595 /* issue the auto-sense command */ 596 srb->resid = 0; 597 temp_result = us->transport(us->srb, us); 598 599 /* let's clean up right away */ 600 scsi_eh_restore_cmnd(srb, &ses); 601 602 if (test_bit(US_FLIDX_TIMED_OUT, &us->flags)) { 603 US_DEBUGP("-- auto-sense aborted\n"); 604 srb->result = DID_ABORT << 16; 605 goto Handle_Errors; 606 } 607 if (temp_result != USB_STOR_TRANSPORT_GOOD) { 608 US_DEBUGP("-- auto-sense failure\n"); 609 610 /* we skip the reset if this happens to be a 611 * multi-target device, since failure of an 612 * auto-sense is perfectly valid 613 */ 614 srb->result = DID_ERROR << 16; 615 if (!(us->flags & US_FL_SCM_MULT_TARG)) 616 goto Handle_Errors; 617 return; 618 } 619 620 US_DEBUGP("-- Result from auto-sense is %d\n", temp_result); 621 US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n", 622 srb->sense_buffer[0], 623 srb->sense_buffer[2] & 0xf, 624 srb->sense_buffer[12], 625 srb->sense_buffer[13]); 626 #ifdef CONFIG_USB_STORAGE_DEBUG 627 usb_stor_show_sense( 628 srb->sense_buffer[2] & 0xf, 629 srb->sense_buffer[12], 630 srb->sense_buffer[13]); 631 #endif 632 633 /* set the result so the higher layers expect this data */ 634 srb->result = SAM_STAT_CHECK_CONDITION; 635 636 /* If things are really okay, then let's show that. Zero 637 * out the sense buffer so the higher layers won't realize 638 * we did an unsolicited auto-sense. */ 639 if (result == USB_STOR_TRANSPORT_GOOD && 640 /* Filemark 0, ignore EOM, ILI 0, no sense */ 641 (srb->sense_buffer[2] & 0xaf) == 0 && 642 /* No ASC or ASCQ */ 643 srb->sense_buffer[12] == 0 && 644 srb->sense_buffer[13] == 0) { 645 srb->result = SAM_STAT_GOOD; 646 srb->sense_buffer[0] = 0x0; 647 } 648 } 649 650 /* Did we transfer less than the minimum amount required? */ 651 if (srb->result == SAM_STAT_GOOD && 652 srb->request_bufflen - srb->resid < srb->underflow) 653 srb->result = (DID_ERROR << 16) | (SUGGEST_RETRY << 24); 654 655 return; 656 657 /* Error and abort processing: try to resynchronize with the device 658 * by issuing a port reset. If that fails, try a class-specific 659 * device reset. */ 660 Handle_Errors: 661 662 /* Set the RESETTING bit, and clear the ABORTING bit so that 663 * the reset may proceed. */ 664 scsi_lock(us_to_host(us)); 665 set_bit(US_FLIDX_RESETTING, &us->flags); 666 clear_bit(US_FLIDX_ABORTING, &us->flags); 667 scsi_unlock(us_to_host(us)); 668 669 /* We must release the device lock because the pre_reset routine 670 * will want to acquire it. */ 671 mutex_unlock(&us->dev_mutex); 672 result = usb_stor_port_reset(us); 673 mutex_lock(&us->dev_mutex); 674 675 if (result < 0) { 676 scsi_lock(us_to_host(us)); 677 usb_stor_report_device_reset(us); 678 scsi_unlock(us_to_host(us)); 679 us->transport_reset(us); 680 } 681 clear_bit(US_FLIDX_RESETTING, &us->flags); 682 } 683 684 /* Stop the current URB transfer */ 685 void usb_stor_stop_transport(struct us_data *us) 686 { 687 US_DEBUGP("%s called\n", __FUNCTION__); 688 689 /* If the state machine is blocked waiting for an URB, 690 * let's wake it up. The test_and_clear_bit() call 691 * guarantees that if a URB has just been submitted, 692 * it won't be cancelled more than once. */ 693 if (test_and_clear_bit(US_FLIDX_URB_ACTIVE, &us->flags)) { 694 US_DEBUGP("-- cancelling URB\n"); 695 usb_unlink_urb(us->current_urb); 696 } 697 698 /* If we are waiting for a scatter-gather operation, cancel it. */ 699 if (test_and_clear_bit(US_FLIDX_SG_ACTIVE, &us->flags)) { 700 US_DEBUGP("-- cancelling sg request\n"); 701 usb_sg_cancel(&us->current_sg); 702 } 703 } 704 705 /* 706 * Control/Bulk/Interrupt transport 707 */ 708 709 int usb_stor_CBI_transport(struct scsi_cmnd *srb, struct us_data *us) 710 { 711 unsigned int transfer_length = srb->request_bufflen; 712 unsigned int pipe = 0; 713 int result; 714 715 /* COMMAND STAGE */ 716 /* let's send the command via the control pipe */ 717 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe, 718 US_CBI_ADSC, 719 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, 720 us->ifnum, srb->cmnd, srb->cmd_len); 721 722 /* check the return code for the command */ 723 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result); 724 725 /* if we stalled the command, it means command failed */ 726 if (result == USB_STOR_XFER_STALLED) { 727 return USB_STOR_TRANSPORT_FAILED; 728 } 729 730 /* Uh oh... serious problem here */ 731 if (result != USB_STOR_XFER_GOOD) { 732 return USB_STOR_TRANSPORT_ERROR; 733 } 734 735 /* DATA STAGE */ 736 /* transfer the data payload for this command, if one exists*/ 737 if (transfer_length) { 738 pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 739 us->recv_bulk_pipe : us->send_bulk_pipe; 740 result = usb_stor_bulk_transfer_sg(us, pipe, 741 srb->request_buffer, transfer_length, 742 srb->use_sg, &srb->resid); 743 US_DEBUGP("CBI data stage result is 0x%x\n", result); 744 745 /* if we stalled the data transfer it means command failed */ 746 if (result == USB_STOR_XFER_STALLED) 747 return USB_STOR_TRANSPORT_FAILED; 748 if (result > USB_STOR_XFER_STALLED) 749 return USB_STOR_TRANSPORT_ERROR; 750 } 751 752 /* STATUS STAGE */ 753 result = usb_stor_intr_transfer(us, us->iobuf, 2); 754 US_DEBUGP("Got interrupt data (0x%x, 0x%x)\n", 755 us->iobuf[0], us->iobuf[1]); 756 if (result != USB_STOR_XFER_GOOD) 757 return USB_STOR_TRANSPORT_ERROR; 758 759 /* UFI gives us ASC and ASCQ, like a request sense 760 * 761 * REQUEST_SENSE and INQUIRY don't affect the sense data on UFI 762 * devices, so we ignore the information for those commands. Note 763 * that this means we could be ignoring a real error on these 764 * commands, but that can't be helped. 765 */ 766 if (us->subclass == US_SC_UFI) { 767 if (srb->cmnd[0] == REQUEST_SENSE || 768 srb->cmnd[0] == INQUIRY) 769 return USB_STOR_TRANSPORT_GOOD; 770 if (us->iobuf[0]) 771 goto Failed; 772 return USB_STOR_TRANSPORT_GOOD; 773 } 774 775 /* If not UFI, we interpret the data as a result code 776 * The first byte should always be a 0x0. 777 * 778 * Some bogus devices don't follow that rule. They stuff the ASC 779 * into the first byte -- so if it's non-zero, call it a failure. 780 */ 781 if (us->iobuf[0]) { 782 US_DEBUGP("CBI IRQ data showed reserved bType 0x%x\n", 783 us->iobuf[0]); 784 goto Failed; 785 786 } 787 788 /* The second byte & 0x0F should be 0x0 for good, otherwise error */ 789 switch (us->iobuf[1] & 0x0F) { 790 case 0x00: 791 return USB_STOR_TRANSPORT_GOOD; 792 case 0x01: 793 goto Failed; 794 } 795 return USB_STOR_TRANSPORT_ERROR; 796 797 /* the CBI spec requires that the bulk pipe must be cleared 798 * following any data-in/out command failure (section 2.4.3.1.3) 799 */ 800 Failed: 801 if (pipe) 802 usb_stor_clear_halt(us, pipe); 803 return USB_STOR_TRANSPORT_FAILED; 804 } 805 806 /* 807 * Control/Bulk transport 808 */ 809 int usb_stor_CB_transport(struct scsi_cmnd *srb, struct us_data *us) 810 { 811 unsigned int transfer_length = srb->request_bufflen; 812 int result; 813 814 /* COMMAND STAGE */ 815 /* let's send the command via the control pipe */ 816 result = usb_stor_ctrl_transfer(us, us->send_ctrl_pipe, 817 US_CBI_ADSC, 818 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 0, 819 us->ifnum, srb->cmnd, srb->cmd_len); 820 821 /* check the return code for the command */ 822 US_DEBUGP("Call to usb_stor_ctrl_transfer() returned %d\n", result); 823 824 /* if we stalled the command, it means command failed */ 825 if (result == USB_STOR_XFER_STALLED) { 826 return USB_STOR_TRANSPORT_FAILED; 827 } 828 829 /* Uh oh... serious problem here */ 830 if (result != USB_STOR_XFER_GOOD) { 831 return USB_STOR_TRANSPORT_ERROR; 832 } 833 834 /* DATA STAGE */ 835 /* transfer the data payload for this command, if one exists*/ 836 if (transfer_length) { 837 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 838 us->recv_bulk_pipe : us->send_bulk_pipe; 839 result = usb_stor_bulk_transfer_sg(us, pipe, 840 srb->request_buffer, transfer_length, 841 srb->use_sg, &srb->resid); 842 US_DEBUGP("CB data stage result is 0x%x\n", result); 843 844 /* if we stalled the data transfer it means command failed */ 845 if (result == USB_STOR_XFER_STALLED) 846 return USB_STOR_TRANSPORT_FAILED; 847 if (result > USB_STOR_XFER_STALLED) 848 return USB_STOR_TRANSPORT_ERROR; 849 } 850 851 /* STATUS STAGE */ 852 /* NOTE: CB does not have a status stage. Silly, I know. So 853 * we have to catch this at a higher level. 854 */ 855 return USB_STOR_TRANSPORT_GOOD; 856 } 857 858 /* 859 * Bulk only transport 860 */ 861 862 /* Determine what the maximum LUN supported is */ 863 int usb_stor_Bulk_max_lun(struct us_data *us) 864 { 865 int result; 866 867 /* issue the command */ 868 us->iobuf[0] = 0; 869 result = usb_stor_control_msg(us, us->recv_ctrl_pipe, 870 US_BULK_GET_MAX_LUN, 871 USB_DIR_IN | USB_TYPE_CLASS | 872 USB_RECIP_INTERFACE, 873 0, us->ifnum, us->iobuf, 1, HZ); 874 875 US_DEBUGP("GetMaxLUN command result is %d, data is %d\n", 876 result, us->iobuf[0]); 877 878 /* if we have a successful request, return the result */ 879 if (result > 0) 880 return us->iobuf[0]; 881 882 /* 883 * Some devices (i.e. Iomega Zip100) need this -- apparently 884 * the bulk pipes get STALLed when the GetMaxLUN request is 885 * processed. This is, in theory, harmless to all other devices 886 * (regardless of if they stall or not). 887 */ 888 if (result == -EPIPE) { 889 usb_stor_clear_halt(us, us->recv_bulk_pipe); 890 usb_stor_clear_halt(us, us->send_bulk_pipe); 891 } 892 893 /* 894 * Some devices don't like GetMaxLUN. They may STALL the control 895 * pipe, they may return a zero-length result, they may do nothing at 896 * all and timeout, or they may fail in even more bizarrely creative 897 * ways. In these cases the best approach is to use the default 898 * value: only one LUN. 899 */ 900 return 0; 901 } 902 903 int usb_stor_Bulk_transport(struct scsi_cmnd *srb, struct us_data *us) 904 { 905 struct bulk_cb_wrap *bcb = (struct bulk_cb_wrap *) us->iobuf; 906 struct bulk_cs_wrap *bcs = (struct bulk_cs_wrap *) us->iobuf; 907 unsigned int transfer_length = srb->request_bufflen; 908 unsigned int residue; 909 int result; 910 int fake_sense = 0; 911 unsigned int cswlen; 912 unsigned int cbwlen = US_BULK_CB_WRAP_LEN; 913 914 /* Take care of BULK32 devices; set extra byte to 0 */ 915 if ( unlikely(us->flags & US_FL_BULK32)) { 916 cbwlen = 32; 917 us->iobuf[31] = 0; 918 } 919 920 /* set up the command wrapper */ 921 bcb->Signature = cpu_to_le32(US_BULK_CB_SIGN); 922 bcb->DataTransferLength = cpu_to_le32(transfer_length); 923 bcb->Flags = srb->sc_data_direction == DMA_FROM_DEVICE ? 1 << 7 : 0; 924 bcb->Tag = ++us->tag; 925 bcb->Lun = srb->device->lun; 926 if (us->flags & US_FL_SCM_MULT_TARG) 927 bcb->Lun |= srb->device->id << 4; 928 bcb->Length = srb->cmd_len; 929 930 /* copy the command payload */ 931 memset(bcb->CDB, 0, sizeof(bcb->CDB)); 932 memcpy(bcb->CDB, srb->cmnd, bcb->Length); 933 934 /* send it to out endpoint */ 935 US_DEBUGP("Bulk Command S 0x%x T 0x%x L %d F %d Trg %d LUN %d CL %d\n", 936 le32_to_cpu(bcb->Signature), bcb->Tag, 937 le32_to_cpu(bcb->DataTransferLength), bcb->Flags, 938 (bcb->Lun >> 4), (bcb->Lun & 0x0F), 939 bcb->Length); 940 result = usb_stor_bulk_transfer_buf(us, us->send_bulk_pipe, 941 bcb, cbwlen, NULL); 942 US_DEBUGP("Bulk command transfer result=%d\n", result); 943 if (result != USB_STOR_XFER_GOOD) 944 return USB_STOR_TRANSPORT_ERROR; 945 946 /* DATA STAGE */ 947 /* send/receive data payload, if there is any */ 948 949 /* Some USB-IDE converter chips need a 100us delay between the 950 * command phase and the data phase. Some devices need a little 951 * more than that, probably because of clock rate inaccuracies. */ 952 if (unlikely(us->flags & US_FL_GO_SLOW)) 953 udelay(125); 954 955 if (transfer_length) { 956 unsigned int pipe = srb->sc_data_direction == DMA_FROM_DEVICE ? 957 us->recv_bulk_pipe : us->send_bulk_pipe; 958 result = usb_stor_bulk_transfer_sg(us, pipe, 959 srb->request_buffer, transfer_length, 960 srb->use_sg, &srb->resid); 961 US_DEBUGP("Bulk data transfer result 0x%x\n", result); 962 if (result == USB_STOR_XFER_ERROR) 963 return USB_STOR_TRANSPORT_ERROR; 964 965 /* If the device tried to send back more data than the 966 * amount requested, the spec requires us to transfer 967 * the CSW anyway. Since there's no point retrying the 968 * the command, we'll return fake sense data indicating 969 * Illegal Request, Invalid Field in CDB. 970 */ 971 if (result == USB_STOR_XFER_LONG) 972 fake_sense = 1; 973 } 974 975 /* See flow chart on pg 15 of the Bulk Only Transport spec for 976 * an explanation of how this code works. 977 */ 978 979 /* get CSW for device status */ 980 US_DEBUGP("Attempting to get CSW...\n"); 981 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 982 bcs, US_BULK_CS_WRAP_LEN, &cswlen); 983 984 /* Some broken devices add unnecessary zero-length packets to the 985 * end of their data transfers. Such packets show up as 0-length 986 * CSWs. If we encounter such a thing, try to read the CSW again. 987 */ 988 if (result == USB_STOR_XFER_SHORT && cswlen == 0) { 989 US_DEBUGP("Received 0-length CSW; retrying...\n"); 990 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 991 bcs, US_BULK_CS_WRAP_LEN, &cswlen); 992 } 993 994 /* did the attempt to read the CSW fail? */ 995 if (result == USB_STOR_XFER_STALLED) { 996 997 /* get the status again */ 998 US_DEBUGP("Attempting to get CSW (2nd try)...\n"); 999 result = usb_stor_bulk_transfer_buf(us, us->recv_bulk_pipe, 1000 bcs, US_BULK_CS_WRAP_LEN, NULL); 1001 } 1002 1003 /* if we still have a failure at this point, we're in trouble */ 1004 US_DEBUGP("Bulk status result = %d\n", result); 1005 if (result != USB_STOR_XFER_GOOD) 1006 return USB_STOR_TRANSPORT_ERROR; 1007 1008 /* check bulk status */ 1009 residue = le32_to_cpu(bcs->Residue); 1010 US_DEBUGP("Bulk Status S 0x%x T 0x%x R %u Stat 0x%x\n", 1011 le32_to_cpu(bcs->Signature), bcs->Tag, 1012 residue, bcs->Status); 1013 if (bcs->Tag != us->tag || bcs->Status > US_BULK_STAT_PHASE) { 1014 US_DEBUGP("Bulk logical error\n"); 1015 return USB_STOR_TRANSPORT_ERROR; 1016 } 1017 1018 /* Some broken devices report odd signatures, so we do not check them 1019 * for validity against the spec. We store the first one we see, 1020 * and check subsequent transfers for validity against this signature. 1021 */ 1022 if (!us->bcs_signature) { 1023 us->bcs_signature = bcs->Signature; 1024 if (us->bcs_signature != cpu_to_le32(US_BULK_CS_SIGN)) 1025 US_DEBUGP("Learnt BCS signature 0x%08X\n", 1026 le32_to_cpu(us->bcs_signature)); 1027 } else if (bcs->Signature != us->bcs_signature) { 1028 US_DEBUGP("Signature mismatch: got %08X, expecting %08X\n", 1029 le32_to_cpu(bcs->Signature), 1030 le32_to_cpu(us->bcs_signature)); 1031 return USB_STOR_TRANSPORT_ERROR; 1032 } 1033 1034 /* try to compute the actual residue, based on how much data 1035 * was really transferred and what the device tells us */ 1036 if (residue) { 1037 if (!(us->flags & US_FL_IGNORE_RESIDUE)) { 1038 residue = min(residue, transfer_length); 1039 srb->resid = max(srb->resid, (int) residue); 1040 } 1041 } 1042 1043 /* based on the status code, we report good or bad */ 1044 switch (bcs->Status) { 1045 case US_BULK_STAT_OK: 1046 /* device babbled -- return fake sense data */ 1047 if (fake_sense) { 1048 memcpy(srb->sense_buffer, 1049 usb_stor_sense_invalidCDB, 1050 sizeof(usb_stor_sense_invalidCDB)); 1051 return USB_STOR_TRANSPORT_NO_SENSE; 1052 } 1053 1054 /* command good -- note that data could be short */ 1055 return USB_STOR_TRANSPORT_GOOD; 1056 1057 case US_BULK_STAT_FAIL: 1058 /* command failed */ 1059 return USB_STOR_TRANSPORT_FAILED; 1060 1061 case US_BULK_STAT_PHASE: 1062 /* phase error -- note that a transport reset will be 1063 * invoked by the invoke_transport() function 1064 */ 1065 return USB_STOR_TRANSPORT_ERROR; 1066 } 1067 1068 /* we should never get here, but if we do, we're in trouble */ 1069 return USB_STOR_TRANSPORT_ERROR; 1070 } 1071 1072 /*********************************************************************** 1073 * Reset routines 1074 ***********************************************************************/ 1075 1076 /* This is the common part of the device reset code. 1077 * 1078 * It's handy that every transport mechanism uses the control endpoint for 1079 * resets. 1080 * 1081 * Basically, we send a reset with a 5-second timeout, so we don't get 1082 * jammed attempting to do the reset. 1083 */ 1084 static int usb_stor_reset_common(struct us_data *us, 1085 u8 request, u8 requesttype, 1086 u16 value, u16 index, void *data, u16 size) 1087 { 1088 int result; 1089 int result2; 1090 1091 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1092 US_DEBUGP("No reset during disconnect\n"); 1093 return -EIO; 1094 } 1095 1096 result = usb_stor_control_msg(us, us->send_ctrl_pipe, 1097 request, requesttype, value, index, data, size, 1098 5*HZ); 1099 if (result < 0) { 1100 US_DEBUGP("Soft reset failed: %d\n", result); 1101 return result; 1102 } 1103 1104 /* Give the device some time to recover from the reset, 1105 * but don't delay disconnect processing. */ 1106 wait_event_interruptible_timeout(us->delay_wait, 1107 test_bit(US_FLIDX_DISCONNECTING, &us->flags), 1108 HZ*6); 1109 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1110 US_DEBUGP("Reset interrupted by disconnect\n"); 1111 return -EIO; 1112 } 1113 1114 US_DEBUGP("Soft reset: clearing bulk-in endpoint halt\n"); 1115 result = usb_stor_clear_halt(us, us->recv_bulk_pipe); 1116 1117 US_DEBUGP("Soft reset: clearing bulk-out endpoint halt\n"); 1118 result2 = usb_stor_clear_halt(us, us->send_bulk_pipe); 1119 1120 /* return a result code based on the result of the clear-halts */ 1121 if (result >= 0) 1122 result = result2; 1123 if (result < 0) 1124 US_DEBUGP("Soft reset failed\n"); 1125 else 1126 US_DEBUGP("Soft reset done\n"); 1127 return result; 1128 } 1129 1130 /* This issues a CB[I] Reset to the device in question 1131 */ 1132 #define CB_RESET_CMD_SIZE 12 1133 1134 int usb_stor_CB_reset(struct us_data *us) 1135 { 1136 US_DEBUGP("%s called\n", __FUNCTION__); 1137 1138 memset(us->iobuf, 0xFF, CB_RESET_CMD_SIZE); 1139 us->iobuf[0] = SEND_DIAGNOSTIC; 1140 us->iobuf[1] = 4; 1141 return usb_stor_reset_common(us, US_CBI_ADSC, 1142 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 1143 0, us->ifnum, us->iobuf, CB_RESET_CMD_SIZE); 1144 } 1145 1146 /* This issues a Bulk-only Reset to the device in question, including 1147 * clearing the subsequent endpoint halts that may occur. 1148 */ 1149 int usb_stor_Bulk_reset(struct us_data *us) 1150 { 1151 US_DEBUGP("%s called\n", __FUNCTION__); 1152 1153 return usb_stor_reset_common(us, US_BULK_RESET_REQUEST, 1154 USB_TYPE_CLASS | USB_RECIP_INTERFACE, 1155 0, us->ifnum, NULL, 0); 1156 } 1157 1158 /* Issue a USB port reset to the device. The caller must not hold 1159 * us->dev_mutex. 1160 */ 1161 int usb_stor_port_reset(struct us_data *us) 1162 { 1163 int result, rc_lock; 1164 1165 result = rc_lock = 1166 usb_lock_device_for_reset(us->pusb_dev, us->pusb_intf); 1167 if (result < 0) 1168 US_DEBUGP("unable to lock device for reset: %d\n", result); 1169 else { 1170 /* Were we disconnected while waiting for the lock? */ 1171 if (test_bit(US_FLIDX_DISCONNECTING, &us->flags)) { 1172 result = -EIO; 1173 US_DEBUGP("No reset during disconnect\n"); 1174 } else { 1175 result = usb_reset_composite_device( 1176 us->pusb_dev, us->pusb_intf); 1177 US_DEBUGP("usb_reset_composite_device returns %d\n", 1178 result); 1179 } 1180 if (rc_lock) 1181 usb_unlock_device(us->pusb_dev); 1182 } 1183 return result; 1184 } 1185