1 /* Driver for USB Mass Storage compliant devices
4 * Current development and maintenance by:
5 * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
7 * Developed with the assistance of:
8 * (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
9 * (c) 2000 Stephen J. Gowdy (SGowdy@lbl.gov)
12 * (c) 1999 Michael Gee (michael@linuxspecific.com)
14 * This driver is based on the 'USB Mass Storage Class' document. This
15 * describes in detail the protocol used to communicate with such
16 * devices. Clearly, the designers had SCSI and ATAPI commands in
17 * mind when they created this document. The commands are all very
18 * similar to commands in the SCSI-II and ATAPI specifications.
20 * It is important to note that in a number of cases this class
21 * exhibits class-specific exemptions from the USB specification.
22 * Notably the usage of NAK, STALL and ACK differs from the norm, in
23 * that they are used to communicate wait, failed and OK on commands.
25 * Also, for certain devices, the interrupt endpoint is used to convey
26 * status of a command.
28 * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
29 * information about this driver.
31 * This program is free software; you can redistribute it and/or modify it
32 * under the terms of the GNU General Public License as published by the
33 * Free Software Foundation; either version 2, or (at your option) any
36 * This program is distributed in the hope that it will be useful, but
37 * WITHOUT ANY WARRANTY; without even the implied warranty of
38 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
39 * General Public License for more details.
41 * You should have received a copy of the GNU General Public License along
42 * with this program; if not, write to the Free Software Foundation, Inc.,
43 * 675 Mass Ave, Cambridge, MA 02139, USA.
46 #include <linux/module.h>
47 #include <linux/mutex.h>
49 #include <scsi/scsi.h>
50 #include <scsi/scsi_cmnd.h>
51 #include <scsi/scsi_devinfo.h>
52 #include <scsi/scsi_device.h>
53 #include <scsi/scsi_eh.h>
58 #include "transport.h"
61 /* Vendor IDs for companies that seem to include the READ CAPACITY bug
62 * in all their devices
64 #define VENDOR_ID_NOKIA 0x0421
65 #define VENDOR_ID_NIKON 0x04b0
66 #define VENDOR_ID_PENTAX 0x0a17
67 #define VENDOR_ID_MOTOROLA 0x22b8
69 /***********************************************************************
71 ***********************************************************************/
73 static const char* host_info(struct Scsi_Host
*host
)
75 struct us_data
*us
= host_to_us(host
);
79 static int slave_alloc (struct scsi_device
*sdev
)
81 struct us_data
*us
= host_to_us(sdev
->host
);
84 * Set the INQUIRY transfer length to 36. We don't use any of
85 * the extra data and many devices choke if asked for more or
88 sdev
->inquiry_len
= 36;
90 /* USB has unusual DMA-alignment requirements: Although the
91 * starting address of each scatter-gather element doesn't matter,
92 * the length of each element except the last must be divisible
93 * by the Bulk maxpacket value. There's currently no way to
94 * express this by block-layer constraints, so we'll cop out
95 * and simply require addresses to be aligned at 512-byte
96 * boundaries. This is okay since most block I/O involves
97 * hardware sectors that are multiples of 512 bytes in length,
98 * and since host controllers up through USB 2.0 have maxpacket
99 * values no larger than 512.
101 * But it doesn't suffice for Wireless USB, where Bulk maxpacket
102 * values can be as large as 2048. To make that work properly
103 * will require changes to the block layer.
105 blk_queue_update_dma_alignment(sdev
->request_queue
, (512 - 1));
107 /* Tell the SCSI layer if we know there is more than one LUN */
108 if (us
->protocol
== USB_PR_BULK
&& us
->max_lun
> 0)
109 sdev
->sdev_bflags
|= BLIST_FORCELUN
;
114 static int slave_configure(struct scsi_device
*sdev
)
116 struct us_data
*us
= host_to_us(sdev
->host
);
118 /* Many devices have trouble transferring more than 32KB at a time,
119 * while others have trouble with more than 64K. At this time we
120 * are limiting both to 32K (64 sectores).
122 if (us
->fflags
& (US_FL_MAX_SECTORS_64
| US_FL_MAX_SECTORS_MIN
)) {
123 unsigned int max_sectors
= 64;
125 if (us
->fflags
& US_FL_MAX_SECTORS_MIN
)
126 max_sectors
= PAGE_CACHE_SIZE
>> 9;
127 if (queue_max_hw_sectors(sdev
->request_queue
) > max_sectors
)
128 blk_queue_max_hw_sectors(sdev
->request_queue
,
130 } else if (sdev
->type
== TYPE_TAPE
) {
131 /* Tapes need much higher max_sector limits, so just
132 * raise it to the maximum possible (4 GB / 512) and
133 * let the queue segment size sort out the real limit.
135 blk_queue_max_hw_sectors(sdev
->request_queue
, 0x7FFFFF);
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
);
146 /* We can't put these settings in slave_alloc() because that gets
147 * called before the device type is known. Consequently these
148 * settings can't be overridden via the scsi devinfo mechanism. */
149 if (sdev
->type
== TYPE_DISK
) {
151 /* Some vendors seem to put the READ CAPACITY bug into
152 * all their devices -- primarily makers of cell phones
153 * and digital cameras. Since these devices always use
154 * flash media and can be expected to have an even number
155 * of sectors, we will always enable the CAPACITY_HEURISTICS
156 * flag unless told otherwise. */
157 switch (le16_to_cpu(us
->pusb_dev
->descriptor
.idVendor
)) {
158 case VENDOR_ID_NOKIA
:
159 case VENDOR_ID_NIKON
:
160 case VENDOR_ID_PENTAX
:
161 case VENDOR_ID_MOTOROLA
:
162 if (!(us
->fflags
& (US_FL_FIX_CAPACITY
|
164 us
->fflags
|= US_FL_CAPACITY_HEURISTICS
;
168 /* Disk-type devices use MODE SENSE(6) if the protocol
169 * (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;
174 /* Many disks only accept MODE SENSE transfer lengths of
175 * 192 bytes (that's what Windows uses). */
176 sdev
->use_192_bytes_for_3f
= 1;
178 /* Some devices don't like MODE SENSE with page=0x3f,
179 * which is the command used for checking if a device
180 * is write-protected. Now that we tell the sd driver
181 * to do a 192-byte transfer with this command the
182 * majority of devices work fine, but a few still can't
183 * handle it. The sd driver will simply assume those
184 * devices are write-enabled. */
185 if (us
->fflags
& US_FL_NO_WP_DETECT
)
186 sdev
->skip_ms_page_3f
= 1;
188 /* A number of devices have problems with MODE SENSE for
189 * page x08, so we will skip it. */
190 sdev
->skip_ms_page_8
= 1;
192 /* Some devices don't handle VPD pages correctly */
193 sdev
->skip_vpd_pages
= 1;
195 /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
196 sdev
->no_report_opcodes
= 1;
198 /* Do not attempt to use WRITE SAME */
199 sdev
->no_write_same
= 1;
201 /* Some disks return the total number of blocks in response
202 * to READ CAPACITY rather than the highest block number.
203 * If this device makes that mistake, tell the sd driver. */
204 if (us
->fflags
& US_FL_FIX_CAPACITY
)
205 sdev
->fix_capacity
= 1;
207 /* A few disks have two indistinguishable version, one of
208 * which reports the correct capacity and the other does not.
209 * The sd driver has to guess which is the case. */
210 if (us
->fflags
& US_FL_CAPACITY_HEURISTICS
)
211 sdev
->guess_capacity
= 1;
213 /* Some devices cannot handle READ_CAPACITY_16 */
214 if (us
->fflags
& US_FL_NO_READ_CAPACITY_16
)
215 sdev
->no_read_capacity_16
= 1;
218 * Many devices do not respond properly to READ_CAPACITY_16.
219 * Tell the SCSI layer to try READ_CAPACITY_10 first.
220 * However some USB 3.0 drive enclosures return capacity
221 * modulo 2TB. Those must use READ_CAPACITY_16
223 if (!(us
->fflags
& US_FL_NEEDS_CAP16
))
224 sdev
->try_rc_10_first
= 1;
226 /* assume SPC3 or latter devices support sense size > 18 */
227 if (sdev
->scsi_level
> SCSI_SPC_2
)
228 us
->fflags
|= US_FL_SANE_SENSE
;
230 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
231 * Hardware Error) when any low-level error occurs,
232 * recoverable or not. Setting this flag tells the SCSI
233 * midlayer to retry such commands, which frequently will
234 * succeed and fix the error. The worst this can lead to
235 * is an occasional series of retries that will all fail. */
236 sdev
->retry_hwerror
= 1;
238 /* USB disks should allow restart. Some drives spin down
239 * automatically, requiring a START-STOP UNIT command. */
240 sdev
->allow_restart
= 1;
242 /* Some USB cardreaders have trouble reading an sdcard's last
243 * sector in a larger then 1 sector read, since the performance
244 * impact is negligible we set this flag for all USB disks */
245 sdev
->last_sector_bug
= 1;
247 /* Enable last-sector hacks for single-target devices using
248 * the Bulk-only transport, unless we already know the
249 * capacity will be decremented or is correct. */
250 if (!(us
->fflags
& (US_FL_FIX_CAPACITY
| US_FL_CAPACITY_OK
|
251 US_FL_SCM_MULT_TARG
)) &&
252 us
->protocol
== USB_PR_BULK
)
253 us
->use_last_sector_hacks
= 1;
255 /* Check if write cache default on flag is set or not */
256 if (us
->fflags
& US_FL_WRITE_CACHE
)
257 sdev
->wce_default_on
= 1;
259 /* A few buggy USB-ATA bridges don't understand FUA */
260 if (us
->fflags
& US_FL_BROKEN_FUA
)
261 sdev
->broken_fua
= 1;
265 /* Non-disk-type devices don't need to blacklist any pages
266 * or to force 192-byte transfer lengths for MODE SENSE.
267 * But they do need to use MODE SENSE(10). */
268 sdev
->use_10_for_ms
= 1;
270 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
271 if (us
->fflags
& US_FL_NO_READ_DISC_INFO
)
272 sdev
->no_read_disc_info
= 1;
275 /* The CB and CBI transports have no way to pass LUN values
276 * other than the bits in the second byte of a CDB. But those
277 * bits don't get set to the LUN value if the device reports
278 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
281 if ((us
->protocol
== USB_PR_CB
|| us
->protocol
== USB_PR_CBI
) &&
282 sdev
->scsi_level
== SCSI_UNKNOWN
)
285 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
286 * REMOVAL command, so suppress those commands. */
287 if (us
->fflags
& US_FL_NOT_LOCKABLE
)
290 /* this is to satisfy the compiler, tho I don't think the
291 * return code is ever checked anywhere. */
295 static int target_alloc(struct scsi_target
*starget
)
297 struct us_data
*us
= host_to_us(dev_to_shost(starget
->dev
.parent
));
300 * Some USB drives don't support REPORT LUNS, even though they
301 * report a SCSI revision level above 2. Tell the SCSI layer
302 * not to issue that command; it will perform a normal sequential
305 starget
->no_report_luns
= 1;
308 * The UFI spec treats the Peripheral Qualifier bits in an
309 * INQUIRY result as reserved and requires devices to set them
310 * to 0. However the SCSI spec requires these bits to be set
311 * to 3 to indicate when a LUN is not present.
313 * Let the scanning code know if this target merely sets
314 * Peripheral Device Type to 0x1f to indicate no LUN.
316 if (us
->subclass
== USB_SC_UFI
)
317 starget
->pdt_1f_for_no_lun
= 1;
322 /* queue a command */
323 /* This is always called with scsi_lock(host) held */
324 static int queuecommand_lck(struct scsi_cmnd
*srb
,
325 void (*done
)(struct scsi_cmnd
*))
327 struct us_data
*us
= host_to_us(srb
->device
->host
);
329 /* check for state-transition errors */
330 if (us
->srb
!= NULL
) {
331 printk(KERN_ERR USB_STORAGE
"Error in %s: us->srb = %p\n",
333 return SCSI_MLQUEUE_HOST_BUSY
;
336 /* fail the command if we are disconnecting */
337 if (test_bit(US_FLIDX_DISCONNECTING
, &us
->dflags
)) {
338 usb_stor_dbg(us
, "Fail command during disconnect\n");
339 srb
->result
= DID_NO_CONNECT
<< 16;
344 /* enqueue the command and wake up the control thread */
345 srb
->scsi_done
= done
;
347 complete(&us
->cmnd_ready
);
352 static DEF_SCSI_QCMD(queuecommand
)
354 /***********************************************************************
355 * Error handling functions
356 ***********************************************************************/
358 /* Command timeout and abort */
359 static int command_abort(struct scsi_cmnd
*srb
)
361 struct us_data
*us
= host_to_us(srb
->device
->host
);
363 usb_stor_dbg(us
, "%s called\n", __func__
);
365 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
366 * bits are protected by the host lock. */
367 scsi_lock(us_to_host(us
));
369 /* Is this command still active? */
370 if (us
->srb
!= srb
) {
371 scsi_unlock(us_to_host(us
));
372 usb_stor_dbg(us
, "-- nothing to abort\n");
376 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
377 * a device reset isn't already in progress (to avoid interfering
378 * with the reset). Note that we must retain the host lock while
379 * calling usb_stor_stop_transport(); otherwise it might interfere
380 * with an auto-reset that begins as soon as we release the lock. */
381 set_bit(US_FLIDX_TIMED_OUT
, &us
->dflags
);
382 if (!test_bit(US_FLIDX_RESETTING
, &us
->dflags
)) {
383 set_bit(US_FLIDX_ABORTING
, &us
->dflags
);
384 usb_stor_stop_transport(us
);
386 scsi_unlock(us_to_host(us
));
388 /* Wait for the aborted command to finish */
389 wait_for_completion(&us
->notify
);
393 /* This invokes the transport reset mechanism to reset the state of the
395 static int device_reset(struct scsi_cmnd
*srb
)
397 struct us_data
*us
= host_to_us(srb
->device
->host
);
400 usb_stor_dbg(us
, "%s called\n", __func__
);
402 /* lock the device pointers and do the reset */
403 mutex_lock(&(us
->dev_mutex
));
404 result
= us
->transport_reset(us
);
405 mutex_unlock(&us
->dev_mutex
);
407 return result
< 0 ? FAILED
: SUCCESS
;
410 /* Simulate a SCSI bus reset by resetting the device's USB port. */
411 static int bus_reset(struct scsi_cmnd
*srb
)
413 struct us_data
*us
= host_to_us(srb
->device
->host
);
416 usb_stor_dbg(us
, "%s called\n", __func__
);
418 result
= usb_stor_port_reset(us
);
419 return result
< 0 ? FAILED
: SUCCESS
;
422 /* Report a driver-initiated device reset to the SCSI layer.
423 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
424 * The caller must own the SCSI host lock. */
425 void usb_stor_report_device_reset(struct us_data
*us
)
428 struct Scsi_Host
*host
= us_to_host(us
);
430 scsi_report_device_reset(host
, 0, 0);
431 if (us
->fflags
& US_FL_SCM_MULT_TARG
) {
432 for (i
= 1; i
< host
->max_id
; ++i
)
433 scsi_report_device_reset(host
, 0, i
);
437 /* Report a driver-initiated bus reset to the SCSI layer.
438 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
439 * The caller must not own the SCSI host lock. */
440 void usb_stor_report_bus_reset(struct us_data
*us
)
442 struct Scsi_Host
*host
= us_to_host(us
);
445 scsi_report_bus_reset(host
, 0);
449 /***********************************************************************
450 * /proc/scsi/ functions
451 ***********************************************************************/
453 static int write_info(struct Scsi_Host
*host
, char *buffer
, int length
)
455 /* if someone is sending us data, just throw it away */
459 /* we use this macro to help us write into the buffer */
461 #define SPRINTF(args...) seq_printf(m, ## args)
463 static int show_info (struct seq_file
*m
, struct Scsi_Host
*host
)
465 struct us_data
*us
= host_to_us(host
);
468 /* print the controller name */
469 SPRINTF(" Host scsi%d: usb-storage\n", host
->host_no
);
471 /* print product, vendor, and serial number strings */
472 if (us
->pusb_dev
->manufacturer
)
473 string
= us
->pusb_dev
->manufacturer
;
474 else if (us
->unusual_dev
->vendorName
)
475 string
= us
->unusual_dev
->vendorName
;
478 SPRINTF(" Vendor: %s\n", string
);
479 if (us
->pusb_dev
->product
)
480 string
= us
->pusb_dev
->product
;
481 else if (us
->unusual_dev
->productName
)
482 string
= us
->unusual_dev
->productName
;
485 SPRINTF(" Product: %s\n", string
);
486 if (us
->pusb_dev
->serial
)
487 string
= us
->pusb_dev
->serial
;
490 SPRINTF("Serial Number: %s\n", string
);
492 /* show the protocol and transport */
493 SPRINTF(" Protocol: %s\n", us
->protocol_name
);
494 SPRINTF(" Transport: %s\n", us
->transport_name
);
496 /* show the device flags */
499 #define US_FLAG(name, value) \
500 if (us->fflags & value) seq_printf(m, " " #name);
507 /***********************************************************************
509 ***********************************************************************/
511 /* Output routine for the sysfs max_sectors file */
512 static ssize_t
max_sectors_show(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
514 struct scsi_device
*sdev
= to_scsi_device(dev
);
516 return sprintf(buf
, "%u\n", queue_max_hw_sectors(sdev
->request_queue
));
519 /* Input routine for the sysfs max_sectors file */
520 static ssize_t
max_sectors_store(struct device
*dev
, struct device_attribute
*attr
, const char *buf
,
523 struct scsi_device
*sdev
= to_scsi_device(dev
);
526 if (sscanf(buf
, "%hu", &ms
) > 0) {
527 blk_queue_max_hw_sectors(sdev
->request_queue
, ms
);
532 static DEVICE_ATTR_RW(max_sectors
);
534 static struct device_attribute
*sysfs_device_attr_list
[] = {
535 &dev_attr_max_sectors
,
540 * this defines our host template, with which we'll allocate hosts
543 struct scsi_host_template usb_stor_host_template
= {
544 /* basic userland interface stuff */
545 .name
= "usb-storage",
546 .proc_name
= "usb-storage",
547 .show_info
= show_info
,
548 .write_info
= write_info
,
551 /* command interface -- queued only */
552 .queuecommand
= queuecommand
,
554 /* error and abort handlers */
555 .eh_abort_handler
= command_abort
,
556 .eh_device_reset_handler
= device_reset
,
557 .eh_bus_reset_handler
= bus_reset
,
559 /* queue commands only, only one command per LUN */
563 /* unknown initiator id */
566 .slave_alloc
= slave_alloc
,
567 .slave_configure
= slave_configure
,
568 .target_alloc
= target_alloc
,
570 /* lots of sg segments can be handled */
571 .sg_tablesize
= SCSI_MAX_SG_CHAIN_SEGMENTS
,
573 /* limit the total size of a transfer to 120 KB */
576 /* merge commands... this seems to help performance, but
577 * periodically someone should test to see which setting is more
585 /* we do our own delay after a device or bus reset */
586 .skip_settle_delay
= 1,
588 /* sysfs device attributes */
589 .sdev_attrs
= sysfs_device_attr_list
,
591 /* module management */
592 .module
= THIS_MODULE
595 /* To Report "Illegal Request: Invalid Field in CDB */
596 unsigned char usb_stor_sense_invalidCDB
[18] = {
597 [0] = 0x70, /* current error */
598 [2] = ILLEGAL_REQUEST
, /* Illegal Request = 0x05 */
599 [7] = 0x0a, /* additional length */
600 [12] = 0x24 /* Invalid Field in CDB */
602 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB
);