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));
108 * The UFI spec treates the Peripheral Qualifier bits in an
109 * INQUIRY result as reserved and requires devices to set them
110 * to 0. However the SCSI spec requires these bits to be set
111 * to 3 to indicate when a LUN is not present.
113 * Let the scanning code know if this target merely sets
114 * Peripheral Device Type to 0x1f to indicate no LUN.
116 if (us
->subclass
== USB_SC_UFI
)
117 sdev
->sdev_target
->pdt_1f_for_no_lun
= 1;
122 static int slave_configure(struct scsi_device
*sdev
)
124 struct us_data
*us
= host_to_us(sdev
->host
);
126 /* Many devices have trouble transfering more than 32KB at a time,
127 * while others have trouble with more than 64K. At this time we
128 * are limiting both to 32K (64 sectores).
130 if (us
->fflags
& (US_FL_MAX_SECTORS_64
| US_FL_MAX_SECTORS_MIN
)) {
131 unsigned int max_sectors
= 64;
133 if (us
->fflags
& US_FL_MAX_SECTORS_MIN
)
134 max_sectors
= PAGE_CACHE_SIZE
>> 9;
135 if (queue_max_hw_sectors(sdev
->request_queue
) > max_sectors
)
136 blk_queue_max_hw_sectors(sdev
->request_queue
,
138 } else if (sdev
->type
== TYPE_TAPE
) {
139 /* Tapes need much higher max_sector limits, so just
140 * raise it to the maximum possible (4 GB / 512) and
141 * let the queue segment size sort out the real limit.
143 blk_queue_max_hw_sectors(sdev
->request_queue
, 0x7FFFFF);
146 /* Some USB host controllers can't do DMA; they have to use PIO.
147 * They indicate this by setting their dma_mask to NULL. For
148 * such controllers we need to make sure the block layer sets
149 * up bounce buffers in addressable memory.
151 if (!us
->pusb_dev
->bus
->controller
->dma_mask
)
152 blk_queue_bounce_limit(sdev
->request_queue
, BLK_BOUNCE_HIGH
);
154 /* We can't put these settings in slave_alloc() because that gets
155 * called before the device type is known. Consequently these
156 * settings can't be overridden via the scsi devinfo mechanism. */
157 if (sdev
->type
== TYPE_DISK
) {
159 /* Some vendors seem to put the READ CAPACITY bug into
160 * all their devices -- primarily makers of cell phones
161 * and digital cameras. Since these devices always use
162 * flash media and can be expected to have an even number
163 * of sectors, we will always enable the CAPACITY_HEURISTICS
164 * flag unless told otherwise. */
165 switch (le16_to_cpu(us
->pusb_dev
->descriptor
.idVendor
)) {
166 case VENDOR_ID_NOKIA
:
167 case VENDOR_ID_NIKON
:
168 case VENDOR_ID_PENTAX
:
169 case VENDOR_ID_MOTOROLA
:
170 if (!(us
->fflags
& (US_FL_FIX_CAPACITY
|
172 us
->fflags
|= US_FL_CAPACITY_HEURISTICS
;
176 /* Disk-type devices use MODE SENSE(6) if the protocol
177 * (SubClass) is Transparent SCSI, otherwise they use
179 if (us
->subclass
!= USB_SC_SCSI
&& us
->subclass
!= USB_SC_CYP_ATACB
)
180 sdev
->use_10_for_ms
= 1;
182 /* Many disks only accept MODE SENSE transfer lengths of
183 * 192 bytes (that's what Windows uses). */
184 sdev
->use_192_bytes_for_3f
= 1;
186 /* Some devices don't like MODE SENSE with page=0x3f,
187 * which is the command used for checking if a device
188 * is write-protected. Now that we tell the sd driver
189 * to do a 192-byte transfer with this command the
190 * majority of devices work fine, but a few still can't
191 * handle it. The sd driver will simply assume those
192 * devices are write-enabled. */
193 if (us
->fflags
& US_FL_NO_WP_DETECT
)
194 sdev
->skip_ms_page_3f
= 1;
196 /* A number of devices have problems with MODE SENSE for
197 * page x08, so we will skip it. */
198 sdev
->skip_ms_page_8
= 1;
200 /* Some disks return the total number of blocks in response
201 * to READ CAPACITY rather than the highest block number.
202 * If this device makes that mistake, tell the sd driver. */
203 if (us
->fflags
& US_FL_FIX_CAPACITY
)
204 sdev
->fix_capacity
= 1;
206 /* A few disks have two indistinguishable version, one of
207 * which reports the correct capacity and the other does not.
208 * The sd driver has to guess which is the case. */
209 if (us
->fflags
& US_FL_CAPACITY_HEURISTICS
)
210 sdev
->guess_capacity
= 1;
212 /* Some devices cannot handle READ_CAPACITY_16 */
213 if (us
->fflags
& US_FL_NO_READ_CAPACITY_16
)
214 sdev
->no_read_capacity_16
= 1;
216 /* assume SPC3 or latter devices support sense size > 18 */
217 if (sdev
->scsi_level
> SCSI_SPC_2
)
218 us
->fflags
|= US_FL_SANE_SENSE
;
220 /* Some devices report a SCSI revision level above 2 but are
221 * unable to handle the REPORT LUNS command (for which
222 * support is mandatory at level 3). Since we already have
223 * a Get-Max-LUN request, we won't lose much by setting the
224 * revision level down to 2. The only devices that would be
225 * affected are those with sparse LUNs. */
226 if (sdev
->scsi_level
> SCSI_2
)
227 sdev
->sdev_target
->scsi_level
=
228 sdev
->scsi_level
= SCSI_2
;
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 negible 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;
256 /* Non-disk-type devices don't need to blacklist any pages
257 * or to force 192-byte transfer lengths for MODE SENSE.
258 * But they do need to use MODE SENSE(10). */
259 sdev
->use_10_for_ms
= 1;
261 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
262 if (us
->fflags
& US_FL_NO_READ_DISC_INFO
)
263 sdev
->no_read_disc_info
= 1;
266 /* The CB and CBI transports have no way to pass LUN values
267 * other than the bits in the second byte of a CDB. But those
268 * bits don't get set to the LUN value if the device reports
269 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
272 if ((us
->protocol
== USB_PR_CB
|| us
->protocol
== USB_PR_CBI
) &&
273 sdev
->scsi_level
== SCSI_UNKNOWN
)
276 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
277 * REMOVAL command, so suppress those commands. */
278 if (us
->fflags
& US_FL_NOT_LOCKABLE
)
281 /* this is to satisfy the compiler, tho I don't think the
282 * return code is ever checked anywhere. */
286 /* queue a command */
287 /* This is always called with scsi_lock(host) held */
288 static int queuecommand(struct scsi_cmnd
*srb
,
289 void (*done
)(struct scsi_cmnd
*))
291 struct us_data
*us
= host_to_us(srb
->device
->host
);
293 US_DEBUGP("%s called\n", __func__
);
295 /* check for state-transition errors */
296 if (us
->srb
!= NULL
) {
297 printk(KERN_ERR USB_STORAGE
"Error in %s: us->srb = %p\n",
299 return SCSI_MLQUEUE_HOST_BUSY
;
302 /* fail the command if we are disconnecting */
303 if (test_bit(US_FLIDX_DISCONNECTING
, &us
->dflags
)) {
304 US_DEBUGP("Fail command during disconnect\n");
305 srb
->result
= DID_NO_CONNECT
<< 16;
310 /* enqueue the command and wake up the control thread */
311 srb
->scsi_done
= done
;
313 complete(&us
->cmnd_ready
);
318 /***********************************************************************
319 * Error handling functions
320 ***********************************************************************/
322 /* Command timeout and abort */
323 static int command_abort(struct scsi_cmnd
*srb
)
325 struct us_data
*us
= host_to_us(srb
->device
->host
);
327 US_DEBUGP("%s called\n", __func__
);
329 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
330 * bits are protected by the host lock. */
331 scsi_lock(us_to_host(us
));
333 /* Is this command still active? */
334 if (us
->srb
!= srb
) {
335 scsi_unlock(us_to_host(us
));
336 US_DEBUGP ("-- nothing to abort\n");
340 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
341 * a device reset isn't already in progress (to avoid interfering
342 * with the reset). Note that we must retain the host lock while
343 * calling usb_stor_stop_transport(); otherwise it might interfere
344 * with an auto-reset that begins as soon as we release the lock. */
345 set_bit(US_FLIDX_TIMED_OUT
, &us
->dflags
);
346 if (!test_bit(US_FLIDX_RESETTING
, &us
->dflags
)) {
347 set_bit(US_FLIDX_ABORTING
, &us
->dflags
);
348 usb_stor_stop_transport(us
);
350 scsi_unlock(us_to_host(us
));
352 /* Wait for the aborted command to finish */
353 wait_for_completion(&us
->notify
);
357 /* This invokes the transport reset mechanism to reset the state of the
359 static int device_reset(struct scsi_cmnd
*srb
)
361 struct us_data
*us
= host_to_us(srb
->device
->host
);
364 US_DEBUGP("%s called\n", __func__
);
366 /* lock the device pointers and do the reset */
367 mutex_lock(&(us
->dev_mutex
));
368 result
= us
->transport_reset(us
);
369 mutex_unlock(&us
->dev_mutex
);
371 return result
< 0 ? FAILED
: SUCCESS
;
374 /* Simulate a SCSI bus reset by resetting the device's USB port. */
375 static int bus_reset(struct scsi_cmnd
*srb
)
377 struct us_data
*us
= host_to_us(srb
->device
->host
);
380 US_DEBUGP("%s called\n", __func__
);
381 result
= usb_stor_port_reset(us
);
382 return result
< 0 ? FAILED
: SUCCESS
;
385 /* Report a driver-initiated device reset to the SCSI layer.
386 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
387 * The caller must own the SCSI host lock. */
388 void usb_stor_report_device_reset(struct us_data
*us
)
391 struct Scsi_Host
*host
= us_to_host(us
);
393 scsi_report_device_reset(host
, 0, 0);
394 if (us
->fflags
& US_FL_SCM_MULT_TARG
) {
395 for (i
= 1; i
< host
->max_id
; ++i
)
396 scsi_report_device_reset(host
, 0, i
);
400 /* Report a driver-initiated bus reset to the SCSI layer.
401 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
402 * The caller must not own the SCSI host lock. */
403 void usb_stor_report_bus_reset(struct us_data
*us
)
405 struct Scsi_Host
*host
= us_to_host(us
);
408 scsi_report_bus_reset(host
, 0);
412 /***********************************************************************
413 * /proc/scsi/ functions
414 ***********************************************************************/
416 /* we use this macro to help us write into the buffer */
418 #define SPRINTF(args...) \
419 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
421 static int proc_info (struct Scsi_Host
*host
, char *buffer
,
422 char **start
, off_t offset
, int length
, int inout
)
424 struct us_data
*us
= host_to_us(host
);
428 /* if someone is sending us data, just throw it away */
432 /* print the controller name */
433 SPRINTF(" Host scsi%d: usb-storage\n", host
->host_no
);
435 /* print product, vendor, and serial number strings */
436 if (us
->pusb_dev
->manufacturer
)
437 string
= us
->pusb_dev
->manufacturer
;
438 else if (us
->unusual_dev
->vendorName
)
439 string
= us
->unusual_dev
->vendorName
;
442 SPRINTF(" Vendor: %s\n", string
);
443 if (us
->pusb_dev
->product
)
444 string
= us
->pusb_dev
->product
;
445 else if (us
->unusual_dev
->productName
)
446 string
= us
->unusual_dev
->productName
;
449 SPRINTF(" Product: %s\n", string
);
450 if (us
->pusb_dev
->serial
)
451 string
= us
->pusb_dev
->serial
;
454 SPRINTF("Serial Number: %s\n", string
);
456 /* show the protocol and transport */
457 SPRINTF(" Protocol: %s\n", us
->protocol_name
);
458 SPRINTF(" Transport: %s\n", us
->transport_name
);
460 /* show the device flags */
461 if (pos
< buffer
+ length
) {
462 pos
+= sprintf(pos
, " Quirks:");
464 #define US_FLAG(name, value) \
465 if (us->fflags & value) pos += sprintf(pos, " " #name);
473 * Calculate start of next buffer, and return value.
475 *start
= buffer
+ offset
;
477 if ((pos
- buffer
) < offset
)
479 else if ((pos
- buffer
- offset
) < length
)
480 return (pos
- buffer
- offset
);
485 /***********************************************************************
487 ***********************************************************************/
489 /* Output routine for the sysfs max_sectors file */
490 static ssize_t
show_max_sectors(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
492 struct scsi_device
*sdev
= to_scsi_device(dev
);
494 return sprintf(buf
, "%u\n", queue_max_hw_sectors(sdev
->request_queue
));
497 /* Input routine for the sysfs max_sectors file */
498 static ssize_t
store_max_sectors(struct device
*dev
, struct device_attribute
*attr
, const char *buf
,
501 struct scsi_device
*sdev
= to_scsi_device(dev
);
504 if (sscanf(buf
, "%hu", &ms
) > 0) {
505 blk_queue_max_hw_sectors(sdev
->request_queue
, ms
);
511 static DEVICE_ATTR(max_sectors
, S_IRUGO
| S_IWUSR
, show_max_sectors
,
514 static struct device_attribute
*sysfs_device_attr_list
[] = {
515 &dev_attr_max_sectors
,
520 * this defines our host template, with which we'll allocate hosts
523 struct scsi_host_template usb_stor_host_template
= {
524 /* basic userland interface stuff */
525 .name
= "usb-storage",
526 .proc_name
= "usb-storage",
527 .proc_info
= proc_info
,
530 /* command interface -- queued only */
531 .queuecommand
= queuecommand
,
533 /* error and abort handlers */
534 .eh_abort_handler
= command_abort
,
535 .eh_device_reset_handler
= device_reset
,
536 .eh_bus_reset_handler
= bus_reset
,
538 /* queue commands only, only one command per LUN */
542 /* unknown initiator id */
545 .slave_alloc
= slave_alloc
,
546 .slave_configure
= slave_configure
,
548 /* lots of sg segments can be handled */
549 .sg_tablesize
= SCSI_MAX_SG_CHAIN_SEGMENTS
,
551 /* limit the total size of a transfer to 120 KB */
554 /* merge commands... this seems to help performance, but
555 * periodically someone should test to see which setting is more
563 /* we do our own delay after a device or bus reset */
564 .skip_settle_delay
= 1,
566 /* sysfs device attributes */
567 .sdev_attrs
= sysfs_device_attr_list
,
569 /* module management */
570 .module
= THIS_MODULE
573 /* To Report "Illegal Request: Invalid Field in CDB */
574 unsigned char usb_stor_sense_invalidCDB
[18] = {
575 [0] = 0x70, /* current error */
576 [2] = ILLEGAL_REQUEST
, /* Illegal Request = 0x05 */
577 [7] = 0x0a, /* additional length */
578 [12] = 0x24 /* Invalid Field in CDB */
580 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB
);