2 * Driver for USB Mass Storage compliant devices
5 * Current development and maintenance by:
6 * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
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)
13 * (c) 1999 Michael Gee (michael@linuxspecific.com)
15 * This driver is based on the 'USB Mass Storage Class' document. This
16 * describes in detail the protocol used to communicate with such
17 * devices. Clearly, the designers had SCSI and ATAPI commands in
18 * mind when they created this document. The commands are all very
19 * similar to commands in the SCSI-II and ATAPI specifications.
21 * It is important to note that in a number of cases this class
22 * exhibits class-specific exemptions from the USB specification.
23 * Notably the usage of NAK, STALL and ACK differs from the norm, in
24 * that they are used to communicate wait, failed and OK on commands.
26 * Also, for certain devices, the interrupt endpoint is used to convey
27 * status of a command.
29 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
30 * information about this driver.
32 * This program is free software; you can redistribute it and/or modify it
33 * under the terms of the GNU General Public License as published by the
34 * Free Software Foundation; either version 2, or (at your option) any
37 * This program is distributed in the hope that it will be useful, but
38 * WITHOUT ANY WARRANTY; without even the implied warranty of
39 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
40 * General Public License for more details.
42 * You should have received a copy of the GNU General Public License along
43 * with this program; if not, write to the Free Software Foundation, Inc.,
44 * 675 Mass Ave, Cambridge, MA 02139, USA.
47 #include <linux/module.h>
48 #include <linux/mutex.h>
50 #include <scsi/scsi.h>
51 #include <scsi/scsi_cmnd.h>
52 #include <scsi/scsi_devinfo.h>
53 #include <scsi/scsi_device.h>
54 #include <scsi/scsi_eh.h>
59 #include "transport.h"
63 * Vendor IDs for companies that seem to include the READ CAPACITY bug
64 * in all their devices
66 #define VENDOR_ID_NOKIA 0x0421
67 #define VENDOR_ID_NIKON 0x04b0
68 #define VENDOR_ID_PENTAX 0x0a17
69 #define VENDOR_ID_MOTOROLA 0x22b8
71 /***********************************************************************
73 ***********************************************************************/
75 static const char* host_info(struct Scsi_Host *host)
77 struct us_data *us = host_to_us(host);
81 static int slave_alloc (struct scsi_device *sdev)
83 struct us_data *us = host_to_us(sdev->host);
86 * Set the INQUIRY transfer length to 36. We don't use any of
87 * the extra data and many devices choke if asked for more or
90 sdev->inquiry_len = 36;
93 * Some host controllers may have alignment requirements.
94 * We'll play it safe by requiring 512-byte alignment always.
96 blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
98 /* Tell the SCSI layer if we know there is more than one LUN */
99 if (us->protocol == USB_PR_BULK && us->max_lun > 0)
100 sdev->sdev_bflags |= BLIST_FORCELUN;
105 static int slave_configure(struct scsi_device *sdev)
107 struct us_data *us = host_to_us(sdev->host);
110 * Many devices have trouble transferring more than 32KB at a time,
111 * while others have trouble with more than 64K. At this time we
112 * are limiting both to 32K (64 sectores).
114 if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
115 unsigned int max_sectors = 64;
117 if (us->fflags & US_FL_MAX_SECTORS_MIN)
118 max_sectors = PAGE_SIZE >> 9;
119 if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
120 blk_queue_max_hw_sectors(sdev->request_queue,
122 } else if (sdev->type == TYPE_TAPE) {
124 * Tapes need much higher max_sector limits, so just
125 * raise it to the maximum possible (4 GB / 512) and
126 * let the queue segment size sort out the real limit.
128 blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF);
129 } else if (us->pusb_dev->speed >= USB_SPEED_SUPER) {
131 * USB3 devices will be limited to 2048 sectors. This gives us
132 * better throughput on most devices.
134 blk_queue_max_hw_sectors(sdev->request_queue, 2048);
138 * Some USB host controllers can't do DMA; they have to use PIO.
139 * They indicate this by setting their dma_mask to NULL. For
140 * such controllers we need to make sure the block layer sets
141 * up bounce buffers in addressable memory.
143 if (!us->pusb_dev->bus->controller->dma_mask)
144 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH);
147 * We can't put these settings in slave_alloc() because that gets
148 * called before the device type is known. Consequently these
149 * settings can't be overridden via the scsi devinfo mechanism.
151 if (sdev->type == TYPE_DISK) {
154 * Some vendors seem to put the READ CAPACITY bug into
155 * all their devices -- primarily makers of cell phones
156 * and digital cameras. Since these devices always use
157 * flash media and can be expected to have an even number
158 * of sectors, we will always enable the CAPACITY_HEURISTICS
159 * flag unless told otherwise.
161 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) {
162 case VENDOR_ID_NOKIA:
163 case VENDOR_ID_NIKON:
164 case VENDOR_ID_PENTAX:
165 case VENDOR_ID_MOTOROLA:
166 if (!(us->fflags & (US_FL_FIX_CAPACITY |
168 us->fflags |= US_FL_CAPACITY_HEURISTICS;
173 * Disk-type devices use MODE SENSE(6) if the protocol
174 * (SubClass) is Transparent SCSI, otherwise they use
177 if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB)
178 sdev->use_10_for_ms = 1;
181 *Many disks only accept MODE SENSE transfer lengths of
182 * 192 bytes (that's what Windows uses).
184 sdev->use_192_bytes_for_3f = 1;
187 * Some devices don't like MODE SENSE with page=0x3f,
188 * which is the command used for checking if a device
189 * is write-protected. Now that we tell the sd driver
190 * to do a 192-byte transfer with this command the
191 * majority of devices work fine, but a few still can't
192 * handle it. The sd driver will simply assume those
193 * devices are write-enabled.
195 if (us->fflags & US_FL_NO_WP_DETECT)
196 sdev->skip_ms_page_3f = 1;
199 * A number of devices have problems with MODE SENSE for
200 * page x08, so we will skip it.
202 sdev->skip_ms_page_8 = 1;
204 /* Some devices don't handle VPD pages correctly */
205 sdev->skip_vpd_pages = 1;
207 /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
208 sdev->no_report_opcodes = 1;
210 /* Do not attempt to use WRITE SAME */
211 sdev->no_write_same = 1;
214 * Some disks return the total number of blocks in response
215 * to READ CAPACITY rather than the highest block number.
216 * If this device makes that mistake, tell the sd driver.
218 if (us->fflags & US_FL_FIX_CAPACITY)
219 sdev->fix_capacity = 1;
222 * A few disks have two indistinguishable version, one of
223 * which reports the correct capacity and the other does not.
224 * The sd driver has to guess which is the case.
226 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
227 sdev->guess_capacity = 1;
229 /* Some devices cannot handle READ_CAPACITY_16 */
230 if (us->fflags & US_FL_NO_READ_CAPACITY_16)
231 sdev->no_read_capacity_16 = 1;
234 * Many devices do not respond properly to READ_CAPACITY_16.
235 * Tell the SCSI layer to try READ_CAPACITY_10 first.
236 * However some USB 3.0 drive enclosures return capacity
237 * modulo 2TB. Those must use READ_CAPACITY_16
239 if (!(us->fflags & US_FL_NEEDS_CAP16))
240 sdev->try_rc_10_first = 1;
243 * assume SPC3 or latter devices support sense size > 18
244 * unless US_FL_BAD_SENSE quirk is specified.
246 if (sdev->scsi_level > SCSI_SPC_2 &&
247 !(us->fflags & US_FL_BAD_SENSE))
248 us->fflags |= US_FL_SANE_SENSE;
251 * USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
252 * Hardware Error) when any low-level error occurs,
253 * recoverable or not. Setting this flag tells the SCSI
254 * midlayer to retry such commands, which frequently will
255 * succeed and fix the error. The worst this can lead to
256 * is an occasional series of retries that will all fail.
258 sdev->retry_hwerror = 1;
261 * USB disks should allow restart. Some drives spin down
262 * automatically, requiring a START-STOP UNIT command.
264 sdev->allow_restart = 1;
267 * Some USB cardreaders have trouble reading an sdcard's last
268 * sector in a larger then 1 sector read, since the performance
269 * impact is negligible we set this flag for all USB disks
271 sdev->last_sector_bug = 1;
274 * Enable last-sector hacks for single-target devices using
275 * the Bulk-only transport, unless we already know the
276 * capacity will be decremented or is correct.
278 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
279 US_FL_SCM_MULT_TARG)) &&
280 us->protocol == USB_PR_BULK)
281 us->use_last_sector_hacks = 1;
283 /* Check if write cache default on flag is set or not */
284 if (us->fflags & US_FL_WRITE_CACHE)
285 sdev->wce_default_on = 1;
287 /* A few buggy USB-ATA bridges don't understand FUA */
288 if (us->fflags & US_FL_BROKEN_FUA)
289 sdev->broken_fua = 1;
291 /* Some even totally fail to indicate a cache */
292 if (us->fflags & US_FL_ALWAYS_SYNC) {
293 /* don't read caching information */
294 sdev->skip_ms_page_8 = 1;
295 sdev->skip_ms_page_3f = 1;
296 /* assume sync is needed */
297 sdev->wce_default_on = 1;
302 * Non-disk-type devices don't need to blacklist any pages
303 * or to force 192-byte transfer lengths for MODE SENSE.
304 * But they do need to use MODE SENSE(10).
306 sdev->use_10_for_ms = 1;
308 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
309 if (us->fflags & US_FL_NO_READ_DISC_INFO)
310 sdev->no_read_disc_info = 1;
314 * The CB and CBI transports have no way to pass LUN values
315 * other than the bits in the second byte of a CDB. But those
316 * bits don't get set to the LUN value if the device reports
317 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
320 if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
321 sdev->scsi_level == SCSI_UNKNOWN)
325 * Some devices choke when they receive a PREVENT-ALLOW MEDIUM
326 * REMOVAL command, so suppress those commands.
328 if (us->fflags & US_FL_NOT_LOCKABLE)
332 * this is to satisfy the compiler, tho I don't think the
333 * return code is ever checked anywhere.
338 static int target_alloc(struct scsi_target *starget)
340 struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent));
343 * Some USB drives don't support REPORT LUNS, even though they
344 * report a SCSI revision level above 2. Tell the SCSI layer
345 * not to issue that command; it will perform a normal sequential
348 starget->no_report_luns = 1;
351 * The UFI spec treats the Peripheral Qualifier bits in an
352 * INQUIRY result as reserved and requires devices to set them
353 * to 0. However the SCSI spec requires these bits to be set
354 * to 3 to indicate when a LUN is not present.
356 * Let the scanning code know if this target merely sets
357 * Peripheral Device Type to 0x1f to indicate no LUN.
359 if (us->subclass == USB_SC_UFI)
360 starget->pdt_1f_for_no_lun = 1;
365 /* queue a command */
366 /* This is always called with scsi_lock(host) held */
367 static int queuecommand_lck(struct scsi_cmnd *srb,
368 void (*done)(struct scsi_cmnd *))
370 struct us_data *us = host_to_us(srb->device->host);
372 /* check for state-transition errors */
373 if (us->srb != NULL) {
374 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
376 return SCSI_MLQUEUE_HOST_BUSY;
379 /* fail the command if we are disconnecting */
380 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
381 usb_stor_dbg(us, "Fail command during disconnect\n");
382 srb->result = DID_NO_CONNECT << 16;
387 if ((us->fflags & US_FL_NO_ATA_1X) &&
388 (srb->cmnd[0] == ATA_12 || srb->cmnd[0] == ATA_16)) {
389 memcpy(srb->sense_buffer, usb_stor_sense_invalidCDB,
390 sizeof(usb_stor_sense_invalidCDB));
391 srb->result = SAM_STAT_CHECK_CONDITION;
396 /* enqueue the command and wake up the control thread */
397 srb->scsi_done = done;
399 complete(&us->cmnd_ready);
404 static DEF_SCSI_QCMD(queuecommand)
406 /***********************************************************************
407 * Error handling functions
408 ***********************************************************************/
410 /* Command timeout and abort */
411 static int command_abort(struct scsi_cmnd *srb)
413 struct us_data *us = host_to_us(srb->device->host);
415 usb_stor_dbg(us, "%s called\n", __func__);
418 * us->srb together with the TIMED_OUT, RESETTING, and ABORTING
419 * bits are protected by the host lock.
421 scsi_lock(us_to_host(us));
423 /* Is this command still active? */
424 if (us->srb != srb) {
425 scsi_unlock(us_to_host(us));
426 usb_stor_dbg(us, "-- nothing to abort\n");
431 * Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
432 * a device reset isn't already in progress (to avoid interfering
433 * with the reset). Note that we must retain the host lock while
434 * calling usb_stor_stop_transport(); otherwise it might interfere
435 * with an auto-reset that begins as soon as we release the lock.
437 set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
438 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
439 set_bit(US_FLIDX_ABORTING, &us->dflags);
440 usb_stor_stop_transport(us);
442 scsi_unlock(us_to_host(us));
444 /* Wait for the aborted command to finish */
445 wait_for_completion(&us->notify);
450 * This invokes the transport reset mechanism to reset the state of the
453 static int device_reset(struct scsi_cmnd *srb)
455 struct us_data *us = host_to_us(srb->device->host);
458 usb_stor_dbg(us, "%s called\n", __func__);
460 /* lock the device pointers and do the reset */
461 mutex_lock(&(us->dev_mutex));
462 result = us->transport_reset(us);
463 mutex_unlock(&us->dev_mutex);
465 return result < 0 ? FAILED : SUCCESS;
468 /* Simulate a SCSI bus reset by resetting the device's USB port. */
469 static int bus_reset(struct scsi_cmnd *srb)
471 struct us_data *us = host_to_us(srb->device->host);
474 usb_stor_dbg(us, "%s called\n", __func__);
476 result = usb_stor_port_reset(us);
477 return result < 0 ? FAILED : SUCCESS;
481 * Report a driver-initiated device reset to the SCSI layer.
482 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
483 * The caller must own the SCSI host lock.
485 void usb_stor_report_device_reset(struct us_data *us)
488 struct Scsi_Host *host = us_to_host(us);
490 scsi_report_device_reset(host, 0, 0);
491 if (us->fflags & US_FL_SCM_MULT_TARG) {
492 for (i = 1; i < host->max_id; ++i)
493 scsi_report_device_reset(host, 0, i);
498 * Report a driver-initiated bus reset to the SCSI layer.
499 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
500 * The caller must not own the SCSI host lock.
502 void usb_stor_report_bus_reset(struct us_data *us)
504 struct Scsi_Host *host = us_to_host(us);
507 scsi_report_bus_reset(host, 0);
511 /***********************************************************************
512 * /proc/scsi/ functions
513 ***********************************************************************/
515 static int write_info(struct Scsi_Host *host, char *buffer, int length)
517 /* if someone is sending us data, just throw it away */
521 static int show_info (struct seq_file *m, struct Scsi_Host *host)
523 struct us_data *us = host_to_us(host);
526 /* print the controller name */
527 seq_printf(m, " Host scsi%d: usb-storage\n", host->host_no);
529 /* print product, vendor, and serial number strings */
530 if (us->pusb_dev->manufacturer)
531 string = us->pusb_dev->manufacturer;
532 else if (us->unusual_dev->vendorName)
533 string = us->unusual_dev->vendorName;
536 seq_printf(m, " Vendor: %s\n", string);
537 if (us->pusb_dev->product)
538 string = us->pusb_dev->product;
539 else if (us->unusual_dev->productName)
540 string = us->unusual_dev->productName;
543 seq_printf(m, " Product: %s\n", string);
544 if (us->pusb_dev->serial)
545 string = us->pusb_dev->serial;
548 seq_printf(m, "Serial Number: %s\n", string);
550 /* show the protocol and transport */
551 seq_printf(m, " Protocol: %s\n", us->protocol_name);
552 seq_printf(m, " Transport: %s\n", us->transport_name);
554 /* show the device flags */
555 seq_printf(m, " Quirks:");
557 #define US_FLAG(name, value) \
558 if (us->fflags & value) seq_printf(m, " " #name);
565 /***********************************************************************
567 ***********************************************************************/
569 /* Output routine for the sysfs max_sectors file */
570 static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
572 struct scsi_device *sdev = to_scsi_device(dev);
574 return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
577 /* Input routine for the sysfs max_sectors file */
578 static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
581 struct scsi_device *sdev = to_scsi_device(dev);
584 if (sscanf(buf, "%hu", &ms) > 0) {
585 blk_queue_max_hw_sectors(sdev->request_queue, ms);
590 static DEVICE_ATTR_RW(max_sectors);
592 static struct device_attribute *sysfs_device_attr_list[] = {
593 &dev_attr_max_sectors,
598 * this defines our host template, with which we'll allocate hosts
601 static const struct scsi_host_template usb_stor_host_template = {
602 /* basic userland interface stuff */
603 .name = "usb-storage",
604 .proc_name = "usb-storage",
605 .show_info = show_info,
606 .write_info = write_info,
609 /* command interface -- queued only */
610 .queuecommand = queuecommand,
612 /* error and abort handlers */
613 .eh_abort_handler = command_abort,
614 .eh_device_reset_handler = device_reset,
615 .eh_bus_reset_handler = bus_reset,
617 /* queue commands only, only one command per LUN */
620 /* unknown initiator id */
623 .slave_alloc = slave_alloc,
624 .slave_configure = slave_configure,
625 .target_alloc = target_alloc,
627 /* lots of sg segments can be handled */
628 .sg_tablesize = SG_MAX_SEGMENTS,
632 * Limit the total size of a transfer to 120 KB.
634 * Some devices are known to choke with anything larger. It seems like
635 * the problem stems from the fact that original IDE controllers had
636 * only an 8-bit register to hold the number of sectors in one transfer
637 * and even those couldn't handle a full 256 sectors.
639 * Because we want to make sure we interoperate with as many devices as
640 * possible, we will maintain a 240 sector transfer size limit for USB
641 * Mass Storage devices.
643 * Tests show that other operating have similar limits with Microsoft
644 * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
645 * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
646 * and 2048 for USB3 devices.
651 * merge commands... this seems to help performance, but
652 * periodically someone should test to see which setting is more
660 /* we do our own delay after a device or bus reset */
661 .skip_settle_delay = 1,
663 /* sysfs device attributes */
664 .sdev_attrs = sysfs_device_attr_list,
666 /* module management */
667 .module = THIS_MODULE
670 void usb_stor_host_template_init(struct scsi_host_template *sht,
671 const char *name, struct module *owner)
673 *sht = usb_stor_host_template;
675 sht->proc_name = name;
678 EXPORT_SYMBOL_GPL(usb_stor_host_template_init);
680 /* To Report "Illegal Request: Invalid Field in CDB */
681 unsigned char usb_stor_sense_invalidCDB[18] = {
682 [0] = 0x70, /* current error */
683 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
684 [7] = 0x0a, /* additional length */
685 [12] = 0x24 /* Invalid Field in CDB */
687 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);