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/slab.h>
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"
62 /* Vendor IDs for companies that seem to include the READ CAPACITY bug
63 * in all their devices
65 #define VENDOR_ID_NOKIA 0x0421
66 #define VENDOR_ID_NIKON 0x04b0
67 #define VENDOR_ID_MOTOROLA 0x22b8
69 /***********************************************************************
71 ***********************************************************************/
73 static const char* host_info(struct Scsi_Host
*host
)
75 return "SCSI emulation for USB Mass Storage devices";
78 static int slave_alloc (struct scsi_device
*sdev
)
80 struct us_data
*us
= host_to_us(sdev
->host
);
83 * Set the INQUIRY transfer length to 36. We don't use any of
84 * the extra data and many devices choke if asked for more or
87 sdev
->inquiry_len
= 36;
89 /* USB has unusual DMA-alignment requirements: Although the
90 * starting address of each scatter-gather element doesn't matter,
91 * the length of each element except the last must be divisible
92 * by the Bulk maxpacket value. There's currently no way to
93 * express this by block-layer constraints, so we'll cop out
94 * and simply require addresses to be aligned at 512-byte
95 * boundaries. This is okay since most block I/O involves
96 * hardware sectors that are multiples of 512 bytes in length,
97 * and since host controllers up through USB 2.0 have maxpacket
98 * values no larger than 512.
100 * But it doesn't suffice for Wireless USB, where Bulk maxpacket
101 * values can be as large as 2048. To make that work properly
102 * will require changes to the block layer.
104 blk_queue_update_dma_alignment(sdev
->request_queue
, (512 - 1));
107 * The UFI spec treates the Peripheral Qualifier bits in an
108 * INQUIRY result as reserved and requires devices to set them
109 * to 0. However the SCSI spec requires these bits to be set
110 * to 3 to indicate when a LUN is not present.
112 * Let the scanning code know if this target merely sets
113 * Peripheral Device Type to 0x1f to indicate no LUN.
115 if (us
->subclass
== US_SC_UFI
)
116 sdev
->sdev_target
->pdt_1f_for_no_lun
= 1;
121 static int slave_configure(struct scsi_device
*sdev
)
123 struct us_data
*us
= host_to_us(sdev
->host
);
125 /* Many devices have trouble transfering more than 32KB at a time,
126 * while others have trouble with more than 64K. At this time we
127 * are limiting both to 32K (64 sectores).
129 if (us
->fflags
& (US_FL_MAX_SECTORS_64
| US_FL_MAX_SECTORS_MIN
)) {
130 unsigned int max_sectors
= 64;
132 if (us
->fflags
& US_FL_MAX_SECTORS_MIN
)
133 max_sectors
= PAGE_CACHE_SIZE
>> 9;
134 if (sdev
->request_queue
->max_sectors
> max_sectors
)
135 blk_queue_max_sectors(sdev
->request_queue
,
139 /* Some USB host controllers can't do DMA; they have to use PIO.
140 * They indicate this by setting their dma_mask to NULL. For
141 * such controllers we need to make sure the block layer sets
142 * up bounce buffers in addressable memory.
144 if (!us
->pusb_dev
->bus
->controller
->dma_mask
)
145 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. */
150 if (sdev
->type
== TYPE_DISK
) {
152 /* Some vendors seem to put the READ CAPACITY bug into
153 * all their devices -- primarily makers of cell phones
154 * and digital cameras. Since these devices always use
155 * flash media and can be expected to have an even number
156 * of sectors, we will always enable the CAPACITY_HEURISTICS
157 * flag unless told otherwise. */
158 switch (le16_to_cpu(us
->pusb_dev
->descriptor
.idVendor
)) {
159 case VENDOR_ID_NOKIA
:
160 case VENDOR_ID_NIKON
:
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
!= US_SC_SCSI
&& us
->subclass
!= US_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 disks return the total number of blocks in response
193 * to READ CAPACITY rather than the highest block number.
194 * If this device makes that mistake, tell the sd driver. */
195 if (us
->fflags
& US_FL_FIX_CAPACITY
)
196 sdev
->fix_capacity
= 1;
198 /* A few disks have two indistinguishable version, one of
199 * which reports the correct capacity and the other does not.
200 * The sd driver has to guess which is the case. */
201 if (us
->fflags
& US_FL_CAPACITY_HEURISTICS
)
202 sdev
->guess_capacity
= 1;
204 /* assume SPC3 or latter devices support sense size > 18 */
205 if (sdev
->scsi_level
> SCSI_SPC_2
)
206 us
->fflags
|= US_FL_SANE_SENSE
;
208 /* Some devices report a SCSI revision level above 2 but are
209 * unable to handle the REPORT LUNS command (for which
210 * support is mandatory at level 3). Since we already have
211 * a Get-Max-LUN request, we won't lose much by setting the
212 * revision level down to 2. The only devices that would be
213 * affected are those with sparse LUNs. */
214 if (sdev
->scsi_level
> SCSI_2
)
215 sdev
->sdev_target
->scsi_level
=
216 sdev
->scsi_level
= SCSI_2
;
218 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
219 * Hardware Error) when any low-level error occurs,
220 * recoverable or not. Setting this flag tells the SCSI
221 * midlayer to retry such commands, which frequently will
222 * succeed and fix the error. The worst this can lead to
223 * is an occasional series of retries that will all fail. */
224 sdev
->retry_hwerror
= 1;
226 /* USB disks should allow restart. Some drives spin down
227 * automatically, requiring a START-STOP UNIT command. */
228 sdev
->allow_restart
= 1;
230 /* Some USB cardreaders have trouble reading an sdcard's last
231 * sector in a larger then 1 sector read, since the performance
232 * impact is negible we set this flag for all USB disks */
233 sdev
->last_sector_bug
= 1;
235 /* Enable last-sector hacks for single-target devices using
236 * the Bulk-only transport, unless we already know the
237 * capacity will be decremented or is correct. */
238 if (!(us
->fflags
& (US_FL_FIX_CAPACITY
| US_FL_CAPACITY_OK
|
239 US_FL_SCM_MULT_TARG
)) &&
240 us
->protocol
== US_PR_BULK
)
241 us
->use_last_sector_hacks
= 1;
244 /* Non-disk-type devices don't need to blacklist any pages
245 * or to force 192-byte transfer lengths for MODE SENSE.
246 * But they do need to use MODE SENSE(10). */
247 sdev
->use_10_for_ms
= 1;
250 /* The CB and CBI transports have no way to pass LUN values
251 * other than the bits in the second byte of a CDB. But those
252 * bits don't get set to the LUN value if the device reports
253 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
256 if ((us
->protocol
== US_PR_CB
|| us
->protocol
== US_PR_CBI
) &&
257 sdev
->scsi_level
== SCSI_UNKNOWN
)
260 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
261 * REMOVAL command, so suppress those commands. */
262 if (us
->fflags
& US_FL_NOT_LOCKABLE
)
265 /* this is to satisfy the compiler, tho I don't think the
266 * return code is ever checked anywhere. */
270 /* queue a command */
271 /* This is always called with scsi_lock(host) held */
272 static int queuecommand(struct scsi_cmnd
*srb
,
273 void (*done
)(struct scsi_cmnd
*))
275 struct us_data
*us
= host_to_us(srb
->device
->host
);
277 US_DEBUGP("%s called\n", __func__
);
279 /* check for state-transition errors */
280 if (us
->srb
!= NULL
) {
281 printk(KERN_ERR USB_STORAGE
"Error in %s: us->srb = %p\n",
283 return SCSI_MLQUEUE_HOST_BUSY
;
286 /* fail the command if we are disconnecting */
287 if (test_bit(US_FLIDX_DISCONNECTING
, &us
->dflags
)) {
288 US_DEBUGP("Fail command during disconnect\n");
289 srb
->result
= DID_NO_CONNECT
<< 16;
294 /* enqueue the command and wake up the control thread */
295 srb
->scsi_done
= done
;
297 complete(&us
->cmnd_ready
);
302 /***********************************************************************
303 * Error handling functions
304 ***********************************************************************/
306 /* Command timeout and abort */
307 static int command_abort(struct scsi_cmnd
*srb
)
309 struct us_data
*us
= host_to_us(srb
->device
->host
);
311 US_DEBUGP("%s called\n", __func__
);
313 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
314 * bits are protected by the host lock. */
315 scsi_lock(us_to_host(us
));
317 /* Is this command still active? */
318 if (us
->srb
!= srb
) {
319 scsi_unlock(us_to_host(us
));
320 US_DEBUGP ("-- nothing to abort\n");
324 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
325 * a device reset isn't already in progress (to avoid interfering
326 * with the reset). Note that we must retain the host lock while
327 * calling usb_stor_stop_transport(); otherwise it might interfere
328 * with an auto-reset that begins as soon as we release the lock. */
329 set_bit(US_FLIDX_TIMED_OUT
, &us
->dflags
);
330 if (!test_bit(US_FLIDX_RESETTING
, &us
->dflags
)) {
331 set_bit(US_FLIDX_ABORTING
, &us
->dflags
);
332 usb_stor_stop_transport(us
);
334 scsi_unlock(us_to_host(us
));
336 /* Wait for the aborted command to finish */
337 wait_for_completion(&us
->notify
);
341 /* This invokes the transport reset mechanism to reset the state of the
343 static int device_reset(struct scsi_cmnd
*srb
)
345 struct us_data
*us
= host_to_us(srb
->device
->host
);
348 US_DEBUGP("%s called\n", __func__
);
350 /* lock the device pointers and do the reset */
351 mutex_lock(&(us
->dev_mutex
));
352 result
= us
->transport_reset(us
);
353 mutex_unlock(&us
->dev_mutex
);
355 return result
< 0 ? FAILED
: SUCCESS
;
358 /* Simulate a SCSI bus reset by resetting the device's USB port. */
359 static int bus_reset(struct scsi_cmnd
*srb
)
361 struct us_data
*us
= host_to_us(srb
->device
->host
);
364 US_DEBUGP("%s called\n", __func__
);
365 result
= usb_stor_port_reset(us
);
366 return result
< 0 ? FAILED
: SUCCESS
;
369 /* Report a driver-initiated device reset to the SCSI layer.
370 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
371 * The caller must own the SCSI host lock. */
372 void usb_stor_report_device_reset(struct us_data
*us
)
375 struct Scsi_Host
*host
= us_to_host(us
);
377 scsi_report_device_reset(host
, 0, 0);
378 if (us
->fflags
& US_FL_SCM_MULT_TARG
) {
379 for (i
= 1; i
< host
->max_id
; ++i
)
380 scsi_report_device_reset(host
, 0, i
);
384 /* Report a driver-initiated bus reset to the SCSI layer.
385 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
386 * The caller must not own the SCSI host lock. */
387 void usb_stor_report_bus_reset(struct us_data
*us
)
389 struct Scsi_Host
*host
= us_to_host(us
);
392 scsi_report_bus_reset(host
, 0);
396 /***********************************************************************
397 * /proc/scsi/ functions
398 ***********************************************************************/
400 /* we use this macro to help us write into the buffer */
402 #define SPRINTF(args...) \
403 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
405 static int proc_info (struct Scsi_Host
*host
, char *buffer
,
406 char **start
, off_t offset
, int length
, int inout
)
408 struct us_data
*us
= host_to_us(host
);
412 /* if someone is sending us data, just throw it away */
416 /* print the controller name */
417 SPRINTF(" Host scsi%d: usb-storage\n", host
->host_no
);
419 /* print product, vendor, and serial number strings */
420 if (us
->pusb_dev
->manufacturer
)
421 string
= us
->pusb_dev
->manufacturer
;
422 else if (us
->unusual_dev
->vendorName
)
423 string
= us
->unusual_dev
->vendorName
;
426 SPRINTF(" Vendor: %s\n", string
);
427 if (us
->pusb_dev
->product
)
428 string
= us
->pusb_dev
->product
;
429 else if (us
->unusual_dev
->productName
)
430 string
= us
->unusual_dev
->productName
;
433 SPRINTF(" Product: %s\n", string
);
434 if (us
->pusb_dev
->serial
)
435 string
= us
->pusb_dev
->serial
;
438 SPRINTF("Serial Number: %s\n", string
);
440 /* show the protocol and transport */
441 SPRINTF(" Protocol: %s\n", us
->protocol_name
);
442 SPRINTF(" Transport: %s\n", us
->transport_name
);
444 /* show the device flags */
445 if (pos
< buffer
+ length
) {
446 pos
+= sprintf(pos
, " Quirks:");
448 #define US_FLAG(name, value) \
449 if (us->fflags & value) pos += sprintf(pos, " " #name);
457 * Calculate start of next buffer, and return value.
459 *start
= buffer
+ offset
;
461 if ((pos
- buffer
) < offset
)
463 else if ((pos
- buffer
- offset
) < length
)
464 return (pos
- buffer
- offset
);
469 /***********************************************************************
471 ***********************************************************************/
473 /* Output routine for the sysfs max_sectors file */
474 static ssize_t
show_max_sectors(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
476 struct scsi_device
*sdev
= to_scsi_device(dev
);
478 return sprintf(buf
, "%u\n", sdev
->request_queue
->max_sectors
);
481 /* Input routine for the sysfs max_sectors file */
482 static ssize_t
store_max_sectors(struct device
*dev
, struct device_attribute
*attr
, const char *buf
,
485 struct scsi_device
*sdev
= to_scsi_device(dev
);
488 if (sscanf(buf
, "%hu", &ms
) > 0 && ms
<= SCSI_DEFAULT_MAX_SECTORS
) {
489 blk_queue_max_sectors(sdev
->request_queue
, ms
);
495 static DEVICE_ATTR(max_sectors
, S_IRUGO
| S_IWUSR
, show_max_sectors
,
498 static struct device_attribute
*sysfs_device_attr_list
[] = {
499 &dev_attr_max_sectors
,
504 * this defines our host template, with which we'll allocate hosts
507 struct scsi_host_template usb_stor_host_template
= {
508 /* basic userland interface stuff */
509 .name
= "usb-storage",
510 .proc_name
= "usb-storage",
511 .proc_info
= proc_info
,
514 /* command interface -- queued only */
515 .queuecommand
= queuecommand
,
517 /* error and abort handlers */
518 .eh_abort_handler
= command_abort
,
519 .eh_device_reset_handler
= device_reset
,
520 .eh_bus_reset_handler
= bus_reset
,
522 /* queue commands only, only one command per LUN */
526 /* unknown initiator id */
529 .slave_alloc
= slave_alloc
,
530 .slave_configure
= slave_configure
,
532 /* lots of sg segments can be handled */
533 .sg_tablesize
= SG_ALL
,
535 /* limit the total size of a transfer to 120 KB */
538 /* merge commands... this seems to help performance, but
539 * periodically someone should test to see which setting is more
547 /* we do our own delay after a device or bus reset */
548 .skip_settle_delay
= 1,
550 /* sysfs device attributes */
551 .sdev_attrs
= sysfs_device_attr_list
,
553 /* module management */
554 .module
= THIS_MODULE
557 /* To Report "Illegal Request: Invalid Field in CDB */
558 unsigned char usb_stor_sense_invalidCDB
[18] = {
559 [0] = 0x70, /* current error */
560 [2] = ILLEGAL_REQUEST
, /* Illegal Request = 0x05 */
561 [7] = 0x0a, /* additional length */
562 [12] = 0x24 /* Invalid Field in CDB */