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 * USB has unusual DMA-alignment requirements: Although the
94 * starting address of each scatter-gather element doesn't matter,
95 * the length of each element except the last must be divisible
96 * by the Bulk maxpacket value. There's currently no way to
97 * express this by block-layer constraints, so we'll cop out
98 * and simply require addresses to be aligned at 512-byte
99 * boundaries. This is okay since most block I/O involves
100 * hardware sectors that are multiples of 512 bytes in length,
101 * and since host controllers up through USB 2.0 have maxpacket
102 * values no larger than 512.
104 * But it doesn't suffice for Wireless USB, where Bulk maxpacket
105 * values can be as large as 2048. To make that work properly
106 * will require changes to the block layer.
108 blk_queue_update_dma_alignment(sdev
->request_queue
, (512 - 1));
110 /* Tell the SCSI layer if we know there is more than one LUN */
111 if (us
->protocol
== USB_PR_BULK
&& us
->max_lun
> 0)
112 sdev
->sdev_bflags
|= BLIST_FORCELUN
;
117 static int slave_configure(struct scsi_device
*sdev
)
119 struct us_data
*us
= host_to_us(sdev
->host
);
122 * Many devices have trouble transferring more than 32KB at a time,
123 * while others have trouble with more than 64K. At this time we
124 * are limiting both to 32K (64 sectores).
126 if (us
->fflags
& (US_FL_MAX_SECTORS_64
| US_FL_MAX_SECTORS_MIN
)) {
127 unsigned int max_sectors
= 64;
129 if (us
->fflags
& US_FL_MAX_SECTORS_MIN
)
130 max_sectors
= PAGE_SIZE
>> 9;
131 if (queue_max_hw_sectors(sdev
->request_queue
) > max_sectors
)
132 blk_queue_max_hw_sectors(sdev
->request_queue
,
134 } else if (sdev
->type
== TYPE_TAPE
) {
136 * Tapes need much higher max_sector limits, so just
137 * raise it to the maximum possible (4 GB / 512) and
138 * let the queue segment size sort out the real limit.
140 blk_queue_max_hw_sectors(sdev
->request_queue
, 0x7FFFFF);
141 } else if (us
->pusb_dev
->speed
>= USB_SPEED_SUPER
) {
143 * USB3 devices will be limited to 2048 sectors. This gives us
144 * better throughput on most devices.
146 blk_queue_max_hw_sectors(sdev
->request_queue
, 2048);
150 * Some USB host controllers can't do DMA; they have to use PIO.
151 * They indicate this by setting their dma_mask to NULL. For
152 * such controllers we need to make sure the block layer sets
153 * up bounce buffers in addressable memory.
155 if (!us
->pusb_dev
->bus
->controller
->dma_mask
)
156 blk_queue_bounce_limit(sdev
->request_queue
, BLK_BOUNCE_HIGH
);
159 * We can't put these settings in slave_alloc() because that gets
160 * called before the device type is known. Consequently these
161 * settings can't be overridden via the scsi devinfo mechanism.
163 if (sdev
->type
== TYPE_DISK
) {
166 * Some vendors seem to put the READ CAPACITY bug into
167 * all their devices -- primarily makers of cell phones
168 * and digital cameras. Since these devices always use
169 * flash media and can be expected to have an even number
170 * of sectors, we will always enable the CAPACITY_HEURISTICS
171 * flag unless told otherwise.
173 switch (le16_to_cpu(us
->pusb_dev
->descriptor
.idVendor
)) {
174 case VENDOR_ID_NOKIA
:
175 case VENDOR_ID_NIKON
:
176 case VENDOR_ID_PENTAX
:
177 case VENDOR_ID_MOTOROLA
:
178 if (!(us
->fflags
& (US_FL_FIX_CAPACITY
|
180 us
->fflags
|= US_FL_CAPACITY_HEURISTICS
;
185 * Disk-type devices use MODE SENSE(6) if the protocol
186 * (SubClass) is Transparent SCSI, otherwise they use
189 if (us
->subclass
!= USB_SC_SCSI
&& us
->subclass
!= USB_SC_CYP_ATACB
)
190 sdev
->use_10_for_ms
= 1;
193 *Many disks only accept MODE SENSE transfer lengths of
194 * 192 bytes (that's what Windows uses).
196 sdev
->use_192_bytes_for_3f
= 1;
199 * Some devices don't like MODE SENSE with page=0x3f,
200 * which is the command used for checking if a device
201 * is write-protected. Now that we tell the sd driver
202 * to do a 192-byte transfer with this command the
203 * majority of devices work fine, but a few still can't
204 * handle it. The sd driver will simply assume those
205 * devices are write-enabled.
207 if (us
->fflags
& US_FL_NO_WP_DETECT
)
208 sdev
->skip_ms_page_3f
= 1;
211 * A number of devices have problems with MODE SENSE for
212 * page x08, so we will skip it.
214 sdev
->skip_ms_page_8
= 1;
216 /* Some devices don't handle VPD pages correctly */
217 sdev
->skip_vpd_pages
= 1;
219 /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
220 sdev
->no_report_opcodes
= 1;
222 /* Do not attempt to use WRITE SAME */
223 sdev
->no_write_same
= 1;
226 * Some disks return the total number of blocks in response
227 * to READ CAPACITY rather than the highest block number.
228 * If this device makes that mistake, tell the sd driver.
230 if (us
->fflags
& US_FL_FIX_CAPACITY
)
231 sdev
->fix_capacity
= 1;
234 * A few disks have two indistinguishable version, one of
235 * which reports the correct capacity and the other does not.
236 * The sd driver has to guess which is the case.
238 if (us
->fflags
& US_FL_CAPACITY_HEURISTICS
)
239 sdev
->guess_capacity
= 1;
241 /* Some devices cannot handle READ_CAPACITY_16 */
242 if (us
->fflags
& US_FL_NO_READ_CAPACITY_16
)
243 sdev
->no_read_capacity_16
= 1;
246 * Many devices do not respond properly to READ_CAPACITY_16.
247 * Tell the SCSI layer to try READ_CAPACITY_10 first.
248 * However some USB 3.0 drive enclosures return capacity
249 * modulo 2TB. Those must use READ_CAPACITY_16
251 if (!(us
->fflags
& US_FL_NEEDS_CAP16
))
252 sdev
->try_rc_10_first
= 1;
254 /* assume SPC3 or latter devices support sense size > 18 */
255 if (sdev
->scsi_level
> SCSI_SPC_2
)
256 us
->fflags
|= US_FL_SANE_SENSE
;
259 * USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
260 * Hardware Error) when any low-level error occurs,
261 * recoverable or not. Setting this flag tells the SCSI
262 * midlayer to retry such commands, which frequently will
263 * succeed and fix the error. The worst this can lead to
264 * is an occasional series of retries that will all fail.
266 sdev
->retry_hwerror
= 1;
269 * USB disks should allow restart. Some drives spin down
270 * automatically, requiring a START-STOP UNIT command.
272 sdev
->allow_restart
= 1;
275 * Some USB cardreaders have trouble reading an sdcard's last
276 * sector in a larger then 1 sector read, since the performance
277 * impact is negligible we set this flag for all USB disks
279 sdev
->last_sector_bug
= 1;
282 * Enable last-sector hacks for single-target devices using
283 * the Bulk-only transport, unless we already know the
284 * capacity will be decremented or is correct.
286 if (!(us
->fflags
& (US_FL_FIX_CAPACITY
| US_FL_CAPACITY_OK
|
287 US_FL_SCM_MULT_TARG
)) &&
288 us
->protocol
== USB_PR_BULK
)
289 us
->use_last_sector_hacks
= 1;
291 /* Check if write cache default on flag is set or not */
292 if (us
->fflags
& US_FL_WRITE_CACHE
)
293 sdev
->wce_default_on
= 1;
295 /* A few buggy USB-ATA bridges don't understand FUA */
296 if (us
->fflags
& US_FL_BROKEN_FUA
)
297 sdev
->broken_fua
= 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 /* enqueue the command and wake up the control thread */
388 srb
->scsi_done
= done
;
390 complete(&us
->cmnd_ready
);
395 static DEF_SCSI_QCMD(queuecommand
)
397 /***********************************************************************
398 * Error handling functions
399 ***********************************************************************/
401 /* Command timeout and abort */
402 static int command_abort(struct scsi_cmnd
*srb
)
404 struct us_data
*us
= host_to_us(srb
->device
->host
);
406 usb_stor_dbg(us
, "%s called\n", __func__
);
409 * us->srb together with the TIMED_OUT, RESETTING, and ABORTING
410 * bits are protected by the host lock.
412 scsi_lock(us_to_host(us
));
414 /* Is this command still active? */
415 if (us
->srb
!= srb
) {
416 scsi_unlock(us_to_host(us
));
417 usb_stor_dbg(us
, "-- nothing to abort\n");
422 * Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
423 * a device reset isn't already in progress (to avoid interfering
424 * with the reset). Note that we must retain the host lock while
425 * calling usb_stor_stop_transport(); otherwise it might interfere
426 * with an auto-reset that begins as soon as we release the lock.
428 set_bit(US_FLIDX_TIMED_OUT
, &us
->dflags
);
429 if (!test_bit(US_FLIDX_RESETTING
, &us
->dflags
)) {
430 set_bit(US_FLIDX_ABORTING
, &us
->dflags
);
431 usb_stor_stop_transport(us
);
433 scsi_unlock(us_to_host(us
));
435 /* Wait for the aborted command to finish */
436 wait_for_completion(&us
->notify
);
441 * This invokes the transport reset mechanism to reset the state of the
444 static int device_reset(struct scsi_cmnd
*srb
)
446 struct us_data
*us
= host_to_us(srb
->device
->host
);
449 usb_stor_dbg(us
, "%s called\n", __func__
);
451 /* lock the device pointers and do the reset */
452 mutex_lock(&(us
->dev_mutex
));
453 result
= us
->transport_reset(us
);
454 mutex_unlock(&us
->dev_mutex
);
456 return result
< 0 ? FAILED
: SUCCESS
;
459 /* Simulate a SCSI bus reset by resetting the device's USB port. */
460 static int bus_reset(struct scsi_cmnd
*srb
)
462 struct us_data
*us
= host_to_us(srb
->device
->host
);
465 usb_stor_dbg(us
, "%s called\n", __func__
);
467 result
= usb_stor_port_reset(us
);
468 return result
< 0 ? FAILED
: SUCCESS
;
472 * Report a driver-initiated device reset to the SCSI layer.
473 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
474 * The caller must own the SCSI host lock.
476 void usb_stor_report_device_reset(struct us_data
*us
)
479 struct Scsi_Host
*host
= us_to_host(us
);
481 scsi_report_device_reset(host
, 0, 0);
482 if (us
->fflags
& US_FL_SCM_MULT_TARG
) {
483 for (i
= 1; i
< host
->max_id
; ++i
)
484 scsi_report_device_reset(host
, 0, i
);
489 * Report a driver-initiated bus reset to the SCSI layer.
490 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
491 * The caller must not own the SCSI host lock.
493 void usb_stor_report_bus_reset(struct us_data
*us
)
495 struct Scsi_Host
*host
= us_to_host(us
);
498 scsi_report_bus_reset(host
, 0);
502 /***********************************************************************
503 * /proc/scsi/ functions
504 ***********************************************************************/
506 static int write_info(struct Scsi_Host
*host
, char *buffer
, int length
)
508 /* if someone is sending us data, just throw it away */
512 static int show_info (struct seq_file
*m
, struct Scsi_Host
*host
)
514 struct us_data
*us
= host_to_us(host
);
517 /* print the controller name */
518 seq_printf(m
, " Host scsi%d: usb-storage\n", host
->host_no
);
520 /* print product, vendor, and serial number strings */
521 if (us
->pusb_dev
->manufacturer
)
522 string
= us
->pusb_dev
->manufacturer
;
523 else if (us
->unusual_dev
->vendorName
)
524 string
= us
->unusual_dev
->vendorName
;
527 seq_printf(m
, " Vendor: %s\n", string
);
528 if (us
->pusb_dev
->product
)
529 string
= us
->pusb_dev
->product
;
530 else if (us
->unusual_dev
->productName
)
531 string
= us
->unusual_dev
->productName
;
534 seq_printf(m
, " Product: %s\n", string
);
535 if (us
->pusb_dev
->serial
)
536 string
= us
->pusb_dev
->serial
;
539 seq_printf(m
, "Serial Number: %s\n", string
);
541 /* show the protocol and transport */
542 seq_printf(m
, " Protocol: %s\n", us
->protocol_name
);
543 seq_printf(m
, " Transport: %s\n", us
->transport_name
);
545 /* show the device flags */
546 seq_printf(m
, " Quirks:");
548 #define US_FLAG(name, value) \
549 if (us->fflags & value) seq_printf(m, " " #name);
556 /***********************************************************************
558 ***********************************************************************/
560 /* Output routine for the sysfs max_sectors file */
561 static ssize_t
max_sectors_show(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
563 struct scsi_device
*sdev
= to_scsi_device(dev
);
565 return sprintf(buf
, "%u\n", queue_max_hw_sectors(sdev
->request_queue
));
568 /* Input routine for the sysfs max_sectors file */
569 static ssize_t
max_sectors_store(struct device
*dev
, struct device_attribute
*attr
, const char *buf
,
572 struct scsi_device
*sdev
= to_scsi_device(dev
);
575 if (sscanf(buf
, "%hu", &ms
) > 0) {
576 blk_queue_max_hw_sectors(sdev
->request_queue
, ms
);
581 static DEVICE_ATTR_RW(max_sectors
);
583 static struct device_attribute
*sysfs_device_attr_list
[] = {
584 &dev_attr_max_sectors
,
589 * this defines our host template, with which we'll allocate hosts
592 static const struct scsi_host_template usb_stor_host_template
= {
593 /* basic userland interface stuff */
594 .name
= "usb-storage",
595 .proc_name
= "usb-storage",
596 .show_info
= show_info
,
597 .write_info
= write_info
,
600 /* command interface -- queued only */
601 .queuecommand
= queuecommand
,
603 /* error and abort handlers */
604 .eh_abort_handler
= command_abort
,
605 .eh_device_reset_handler
= device_reset
,
606 .eh_bus_reset_handler
= bus_reset
,
608 /* queue commands only, only one command per LUN */
611 /* unknown initiator id */
614 .slave_alloc
= slave_alloc
,
615 .slave_configure
= slave_configure
,
616 .target_alloc
= target_alloc
,
618 /* lots of sg segments can be handled */
619 .sg_tablesize
= SG_MAX_SEGMENTS
,
623 * Limit the total size of a transfer to 120 KB.
625 * Some devices are known to choke with anything larger. It seems like
626 * the problem stems from the fact that original IDE controllers had
627 * only an 8-bit register to hold the number of sectors in one transfer
628 * and even those couldn't handle a full 256 sectors.
630 * Because we want to make sure we interoperate with as many devices as
631 * possible, we will maintain a 240 sector transfer size limit for USB
632 * Mass Storage devices.
634 * Tests show that other operating have similar limits with Microsoft
635 * Windows 7 limiting transfers to 128 sectors for both USB2 and USB3
636 * and Apple Mac OS X 10.11 limiting transfers to 256 sectors for USB2
637 * and 2048 for USB3 devices.
642 * merge commands... this seems to help performance, but
643 * periodically someone should test to see which setting is more
651 /* we do our own delay after a device or bus reset */
652 .skip_settle_delay
= 1,
654 /* sysfs device attributes */
655 .sdev_attrs
= sysfs_device_attr_list
,
657 /* module management */
658 .module
= THIS_MODULE
661 void usb_stor_host_template_init(struct scsi_host_template
*sht
,
662 const char *name
, struct module
*owner
)
664 *sht
= usb_stor_host_template
;
666 sht
->proc_name
= name
;
669 EXPORT_SYMBOL_GPL(usb_stor_host_template_init
);
671 /* To Report "Illegal Request: Invalid Field in CDB */
672 unsigned char usb_stor_sense_invalidCDB
[18] = {
673 [0] = 0x70, /* current error */
674 [2] = ILLEGAL_REQUEST
, /* Illegal Request = 0x05 */
675 [7] = 0x0a, /* additional length */
676 [12] = 0x24 /* Invalid Field in CDB */
678 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB
);