1 // SPDX-License-Identifier: GPL-2.0+
3 * Driver for USB Mass Storage compliant devices
6 * Current development and maintenance by:
7 * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
9 * Developed with the assistance of:
10 * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
11 * (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
14 * (c) 1999 Michael Gee (michael@linuxspecific.com)
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.
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.
27 * Also, for certain devices, the interrupt endpoint is used to convey
28 * status of a command.
31 #include <linux/module.h>
32 #include <linux/mutex.h>
34 #include <scsi/scsi.h>
35 #include <scsi/scsi_cmnd.h>
36 #include <scsi/scsi_devinfo.h>
37 #include <scsi/scsi_device.h>
38 #include <scsi/scsi_eh.h>
43 #include "transport.h"
47 * Vendor IDs for companies that seem to include the READ CAPACITY bug
48 * in all their devices
50 #define VENDOR_ID_NOKIA 0x0421
51 #define VENDOR_ID_NIKON 0x04b0
52 #define VENDOR_ID_PENTAX 0x0a17
53 #define VENDOR_ID_MOTOROLA 0x22b8
55 /***********************************************************************
57 ***********************************************************************/
59 static const char* host_info(struct Scsi_Host *host)
61 struct us_data *us = host_to_us(host);
65 static int slave_alloc (struct scsi_device *sdev)
67 struct us_data *us = host_to_us(sdev->host);
71 * Set the INQUIRY transfer length to 36. We don't use any of
72 * the extra data and many devices choke if asked for more or
75 sdev->inquiry_len = 36;
78 * USB has unusual scatter-gather requirements: the length of each
79 * scatterlist element except the last must be divisible by the
80 * Bulk maxpacket value. Fortunately this value is always a
81 * power of 2. Inform the block layer about this requirement.
83 maxp = usb_maxpacket(us->pusb_dev, us->recv_bulk_pipe, 0);
84 blk_queue_virt_boundary(sdev->request_queue, maxp - 1);
87 * Some host controllers may have alignment requirements.
88 * We'll play it safe by requiring 512-byte alignment always.
90 blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
92 /* Tell the SCSI layer if we know there is more than one LUN */
93 if (us->protocol == USB_PR_BULK && us->max_lun > 0)
94 sdev->sdev_bflags |= BLIST_FORCELUN;
99 static int slave_configure(struct scsi_device *sdev)
101 struct us_data *us = host_to_us(sdev->host);
104 * Many devices have trouble transferring more than 32KB at a time,
105 * while others have trouble with more than 64K. At this time we
106 * are limiting both to 32K (64 sectores).
108 if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
109 unsigned int max_sectors = 64;
111 if (us->fflags & US_FL_MAX_SECTORS_MIN)
112 max_sectors = PAGE_SIZE >> 9;
113 if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
114 blk_queue_max_hw_sectors(sdev->request_queue,
116 } else if (sdev->type == TYPE_TAPE) {
118 * Tapes need much higher max_sector limits, so just
119 * raise it to the maximum possible (4 GB / 512) and
120 * let the queue segment size sort out the real limit.
122 blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF);
123 } else if (us->pusb_dev->speed >= USB_SPEED_SUPER) {
125 * USB3 devices will be limited to 2048 sectors. This gives us
126 * better throughput on most devices.
128 blk_queue_max_hw_sectors(sdev->request_queue, 2048);
132 * Some USB host controllers can't do DMA; they have to use PIO.
133 * They indicate this by setting their dma_mask to NULL. For
134 * such controllers we need to make sure the block layer sets
135 * up bounce buffers in addressable memory.
137 if (!us->pusb_dev->bus->controller->dma_mask)
138 blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH);
141 * We can't put these settings in slave_alloc() because that gets
142 * called before the device type is known. Consequently these
143 * settings can't be overridden via the scsi devinfo mechanism.
145 if (sdev->type == TYPE_DISK) {
148 * Some vendors seem to put the READ CAPACITY bug into
149 * all their devices -- primarily makers of cell phones
150 * and digital cameras. Since these devices always use
151 * flash media and can be expected to have an even number
152 * of sectors, we will always enable the CAPACITY_HEURISTICS
153 * flag unless told otherwise.
155 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) {
156 case VENDOR_ID_NOKIA:
157 case VENDOR_ID_NIKON:
158 case VENDOR_ID_PENTAX:
159 case VENDOR_ID_MOTOROLA:
160 if (!(us->fflags & (US_FL_FIX_CAPACITY |
162 us->fflags |= US_FL_CAPACITY_HEURISTICS;
167 * Disk-type devices use MODE SENSE(6) if the protocol
168 * (SubClass) is Transparent SCSI, otherwise they use
171 if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB)
172 sdev->use_10_for_ms = 1;
175 *Many disks only accept MODE SENSE transfer lengths of
176 * 192 bytes (that's what Windows uses).
178 sdev->use_192_bytes_for_3f = 1;
181 * Some devices don't like MODE SENSE with page=0x3f,
182 * which is the command used for checking if a device
183 * is write-protected. Now that we tell the sd driver
184 * to do a 192-byte transfer with this command the
185 * majority of devices work fine, but a few still can't
186 * handle it. The sd driver will simply assume those
187 * devices are write-enabled.
189 if (us->fflags & US_FL_NO_WP_DETECT)
190 sdev->skip_ms_page_3f = 1;
193 * A number of devices have problems with MODE SENSE for
194 * page x08, so we will skip it.
196 sdev->skip_ms_page_8 = 1;
198 /* Some devices don't handle VPD pages correctly */
199 sdev->skip_vpd_pages = 1;
201 /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
202 sdev->no_report_opcodes = 1;
204 /* Do not attempt to use WRITE SAME */
205 sdev->no_write_same = 1;
208 * Some disks return the total number of blocks in response
209 * to READ CAPACITY rather than the highest block number.
210 * If this device makes that mistake, tell the sd driver.
212 if (us->fflags & US_FL_FIX_CAPACITY)
213 sdev->fix_capacity = 1;
216 * A few disks have two indistinguishable version, one of
217 * which reports the correct capacity and the other does not.
218 * The sd driver has to guess which is the case.
220 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
221 sdev->guess_capacity = 1;
223 /* Some devices cannot handle READ_CAPACITY_16 */
224 if (us->fflags & US_FL_NO_READ_CAPACITY_16)
225 sdev->no_read_capacity_16 = 1;
228 * Many devices do not respond properly to READ_CAPACITY_16.
229 * Tell the SCSI layer to try READ_CAPACITY_10 first.
230 * However some USB 3.0 drive enclosures return capacity
231 * modulo 2TB. Those must use READ_CAPACITY_16
233 if (!(us->fflags & US_FL_NEEDS_CAP16))
234 sdev->try_rc_10_first = 1;
237 * assume SPC3 or latter devices support sense size > 18
238 * unless US_FL_BAD_SENSE quirk is specified.
240 if (sdev->scsi_level > SCSI_SPC_2 &&
241 !(us->fflags & US_FL_BAD_SENSE))
242 us->fflags |= US_FL_SANE_SENSE;
245 * USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
246 * Hardware Error) when any low-level error occurs,
247 * recoverable or not. Setting this flag tells the SCSI
248 * midlayer to retry such commands, which frequently will
249 * succeed and fix the error. The worst this can lead to
250 * is an occasional series of retries that will all fail.
252 sdev->retry_hwerror = 1;
255 * USB disks should allow restart. Some drives spin down
256 * automatically, requiring a START-STOP UNIT command.
258 sdev->allow_restart = 1;
261 * Some USB cardreaders have trouble reading an sdcard's last
262 * sector in a larger then 1 sector read, since the performance
263 * impact is negligible we set this flag for all USB disks
265 sdev->last_sector_bug = 1;
268 * Enable last-sector hacks for single-target devices using
269 * the Bulk-only transport, unless we already know the
270 * capacity will be decremented or is correct.
272 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
273 US_FL_SCM_MULT_TARG)) &&
274 us->protocol == USB_PR_BULK)
275 us->use_last_sector_hacks = 1;
277 /* Check if write cache default on flag is set or not */
278 if (us->fflags & US_FL_WRITE_CACHE)
279 sdev->wce_default_on = 1;
281 /* A few buggy USB-ATA bridges don't understand FUA */
282 if (us->fflags & US_FL_BROKEN_FUA)
283 sdev->broken_fua = 1;
285 /* Some even totally fail to indicate a cache */
286 if (us->fflags & US_FL_ALWAYS_SYNC) {
287 /* don't read caching information */
288 sdev->skip_ms_page_8 = 1;
289 sdev->skip_ms_page_3f = 1;
290 /* assume sync is needed */
291 sdev->wce_default_on = 1;
296 * Non-disk-type devices don't need to blacklist any pages
297 * or to force 192-byte transfer lengths for MODE SENSE.
298 * But they do need to use MODE SENSE(10).
300 sdev->use_10_for_ms = 1;
302 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
303 if (us->fflags & US_FL_NO_READ_DISC_INFO)
304 sdev->no_read_disc_info = 1;
308 * The CB and CBI transports have no way to pass LUN values
309 * other than the bits in the second byte of a CDB. But those
310 * bits don't get set to the LUN value if the device reports
311 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
314 if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
315 sdev->scsi_level == SCSI_UNKNOWN)
319 * Some devices choke when they receive a PREVENT-ALLOW MEDIUM
320 * REMOVAL command, so suppress those commands.
322 if (us->fflags & US_FL_NOT_LOCKABLE)
326 * this is to satisfy the compiler, tho I don't think the
327 * return code is ever checked anywhere.
332 static int target_alloc(struct scsi_target *starget)
334 struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent));
337 * Some USB drives don't support REPORT LUNS, even though they
338 * report a SCSI revision level above 2. Tell the SCSI layer
339 * not to issue that command; it will perform a normal sequential
342 starget->no_report_luns = 1;
345 * The UFI spec treats the Peripheral Qualifier bits in an
346 * INQUIRY result as reserved and requires devices to set them
347 * to 0. However the SCSI spec requires these bits to be set
348 * to 3 to indicate when a LUN is not present.
350 * Let the scanning code know if this target merely sets
351 * Peripheral Device Type to 0x1f to indicate no LUN.
353 if (us->subclass == USB_SC_UFI)
354 starget->pdt_1f_for_no_lun = 1;
359 /* queue a command */
360 /* This is always called with scsi_lock(host) held */
361 static int queuecommand_lck(struct scsi_cmnd *srb,
362 void (*done)(struct scsi_cmnd *))
364 struct us_data *us = host_to_us(srb->device->host);
366 /* check for state-transition errors */
367 if (us->srb != NULL) {
368 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
370 return SCSI_MLQUEUE_HOST_BUSY;
373 /* fail the command if we are disconnecting */
374 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
375 usb_stor_dbg(us, "Fail command during disconnect\n");
376 srb->result = DID_NO_CONNECT << 16;
381 if ((us->fflags & US_FL_NO_ATA_1X) &&
382 (srb->cmnd[0] == ATA_12 || srb->cmnd[0] == ATA_16)) {
383 memcpy(srb->sense_buffer, usb_stor_sense_invalidCDB,
384 sizeof(usb_stor_sense_invalidCDB));
385 srb->result = SAM_STAT_CHECK_CONDITION;
390 /* enqueue the command and wake up the control thread */
391 srb->scsi_done = done;
393 complete(&us->cmnd_ready);
398 static DEF_SCSI_QCMD(queuecommand)
400 /***********************************************************************
401 * Error handling functions
402 ***********************************************************************/
404 /* Command timeout and abort */
405 static int command_abort(struct scsi_cmnd *srb)
407 struct us_data *us = host_to_us(srb->device->host);
409 usb_stor_dbg(us, "%s called\n", __func__);
412 * us->srb together with the TIMED_OUT, RESETTING, and ABORTING
413 * bits are protected by the host lock.
415 scsi_lock(us_to_host(us));
417 /* Is this command still active? */
418 if (us->srb != srb) {
419 scsi_unlock(us_to_host(us));
420 usb_stor_dbg(us, "-- nothing to abort\n");
425 * Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
426 * a device reset isn't already in progress (to avoid interfering
427 * with the reset). Note that we must retain the host lock while
428 * calling usb_stor_stop_transport(); otherwise it might interfere
429 * with an auto-reset that begins as soon as we release the lock.
431 set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
432 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
433 set_bit(US_FLIDX_ABORTING, &us->dflags);
434 usb_stor_stop_transport(us);
436 scsi_unlock(us_to_host(us));
438 /* Wait for the aborted command to finish */
439 wait_for_completion(&us->notify);
444 * This invokes the transport reset mechanism to reset the state of the
447 static int device_reset(struct scsi_cmnd *srb)
449 struct us_data *us = host_to_us(srb->device->host);
452 usb_stor_dbg(us, "%s called\n", __func__);
454 /* lock the device pointers and do the reset */
455 mutex_lock(&(us->dev_mutex));
456 result = us->transport_reset(us);
457 mutex_unlock(&us->dev_mutex);
459 return result < 0 ? FAILED : SUCCESS;
462 /* Simulate a SCSI bus reset by resetting the device's USB port. */
463 static int bus_reset(struct scsi_cmnd *srb)
465 struct us_data *us = host_to_us(srb->device->host);
468 usb_stor_dbg(us, "%s called\n", __func__);
470 result = usb_stor_port_reset(us);
471 return result < 0 ? FAILED : SUCCESS;
475 * Report a driver-initiated device reset to the SCSI layer.
476 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
477 * The caller must own the SCSI host lock.
479 void usb_stor_report_device_reset(struct us_data *us)
482 struct Scsi_Host *host = us_to_host(us);
484 scsi_report_device_reset(host, 0, 0);
485 if (us->fflags & US_FL_SCM_MULT_TARG) {
486 for (i = 1; i < host->max_id; ++i)
487 scsi_report_device_reset(host, 0, i);
492 * Report a driver-initiated bus reset to the SCSI layer.
493 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
494 * The caller must not own the SCSI host lock.
496 void usb_stor_report_bus_reset(struct us_data *us)
498 struct Scsi_Host *host = us_to_host(us);
501 scsi_report_bus_reset(host, 0);
505 /***********************************************************************
506 * /proc/scsi/ functions
507 ***********************************************************************/
509 static int write_info(struct Scsi_Host *host, char *buffer, int length)
511 /* if someone is sending us data, just throw it away */
515 static int show_info (struct seq_file *m, struct Scsi_Host *host)
517 struct us_data *us = host_to_us(host);
520 /* print the controller name */
521 seq_printf(m, " Host scsi%d: usb-storage\n", host->host_no);
523 /* print product, vendor, and serial number strings */
524 if (us->pusb_dev->manufacturer)
525 string = us->pusb_dev->manufacturer;
526 else if (us->unusual_dev->vendorName)
527 string = us->unusual_dev->vendorName;
530 seq_printf(m, " Vendor: %s\n", string);
531 if (us->pusb_dev->product)
532 string = us->pusb_dev->product;
533 else if (us->unusual_dev->productName)
534 string = us->unusual_dev->productName;
537 seq_printf(m, " Product: %s\n", string);
538 if (us->pusb_dev->serial)
539 string = us->pusb_dev->serial;
542 seq_printf(m, "Serial Number: %s\n", string);
544 /* show the protocol and transport */
545 seq_printf(m, " Protocol: %s\n", us->protocol_name);
546 seq_printf(m, " Transport: %s\n", us->transport_name);
548 /* show the device flags */
549 seq_printf(m, " Quirks:");
551 #define US_FLAG(name, value) \
552 if (us->fflags & value) seq_printf(m, " " #name);
559 /***********************************************************************
561 ***********************************************************************/
563 /* Output routine for the sysfs max_sectors file */
564 static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
566 struct scsi_device *sdev = to_scsi_device(dev);
568 return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
571 /* Input routine for the sysfs max_sectors file */
572 static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
575 struct scsi_device *sdev = to_scsi_device(dev);
578 if (sscanf(buf, "%hu", &ms) > 0) {
579 blk_queue_max_hw_sectors(sdev->request_queue, ms);
584 static DEVICE_ATTR_RW(max_sectors);
586 static struct device_attribute *sysfs_device_attr_list[] = {
587 &dev_attr_max_sectors,
592 * this defines our host template, with which we'll allocate hosts
595 static const struct scsi_host_template usb_stor_host_template = {
596 /* basic userland interface stuff */
597 .name = "usb-storage",
598 .proc_name = "usb-storage",
599 .show_info = show_info,
600 .write_info = write_info,
603 /* command interface -- queued only */
604 .queuecommand = queuecommand,
606 /* error and abort handlers */
607 .eh_abort_handler = command_abort,
608 .eh_device_reset_handler = device_reset,
609 .eh_bus_reset_handler = bus_reset,
611 /* queue commands only, only one command per LUN */
614 /* unknown initiator id */
617 .slave_alloc = slave_alloc,
618 .slave_configure = slave_configure,
619 .target_alloc = target_alloc,
621 /* lots of sg segments can be handled */
622 .sg_tablesize = SG_MAX_SEGMENTS,
626 * Limit the total size of a transfer to 120 KB.
628 * Some devices are known to choke with anything larger. It seems like
629 * the problem stems from the fact that original IDE controllers had
630 * only an 8-bit register to hold the number of sectors in one transfer
631 * and even those couldn't handle a full 256 sectors.
633 * Because we want to make sure we interoperate with as many devices as
634 * possible, we will maintain a 240 sector transfer size limit for USB
635 * Mass Storage devices.
637 * Tests show that other operating have similar limits with Microsoft
638 * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
639 * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
640 * and 2048 for USB3 devices.
647 /* we do our own delay after a device or bus reset */
648 .skip_settle_delay = 1,
650 /* sysfs device attributes */
651 .sdev_attrs = sysfs_device_attr_list,
653 /* module management */
654 .module = THIS_MODULE
657 void usb_stor_host_template_init(struct scsi_host_template *sht,
658 const char *name, struct module *owner)
660 *sht = usb_stor_host_template;
662 sht->proc_name = name;
665 EXPORT_SYMBOL_GPL(usb_stor_host_template_init);
667 /* To Report "Illegal Request: Invalid Field in CDB */
668 unsigned char usb_stor_sense_invalidCDB[18] = {
669 [0] = 0x70, /* current error */
670 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
671 [7] = 0x0a, /* additional length */
672 [12] = 0x24 /* Invalid Field in CDB */
674 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);