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;
119 /* Tell the SCSI layer if we know there is more than one LUN */
120 if (us->protocol == USB_PR_BULK && us->max_lun > 0)
121 sdev->sdev_bflags |= BLIST_FORCELUN;
126 static int slave_configure(struct scsi_device *sdev)
128 struct us_data *us = host_to_us(sdev->host);
130 /* Many devices have trouble transferring more than 32KB at a time,
131 * while others have trouble with more than 64K. At this time we
132 * are limiting both to 32K (64 sectores).
134 if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
135 unsigned int max_sectors = 64;
137 if (us->fflags & US_FL_MAX_SECTORS_MIN)
138 max_sectors = PAGE_CACHE_SIZE >> 9;
139 if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
140 blk_queue_max_hw_sectors(sdev->request_queue,
142 } else if (sdev->type == TYPE_TAPE) {
143 /* Tapes need much higher max_sector limits, so just
144 * raise it to the maximum possible (4 GB / 512) and
145 * let the queue segment size sort out the real limit.
147 blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF);
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);
158 /* We can't put these settings in slave_alloc() because that gets
159 * called before the device type is known. Consequently these
160 * settings can't be overridden via the scsi devinfo mechanism. */
161 if (sdev->type == TYPE_DISK) {
163 /* Some vendors seem to put the READ CAPACITY bug into
164 * all their devices -- primarily makers of cell phones
165 * and digital cameras. Since these devices always use
166 * flash media and can be expected to have an even number
167 * of sectors, we will always enable the CAPACITY_HEURISTICS
168 * flag unless told otherwise. */
169 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) {
170 case VENDOR_ID_NOKIA:
171 case VENDOR_ID_NIKON:
172 case VENDOR_ID_PENTAX:
173 case VENDOR_ID_MOTOROLA:
174 if (!(us->fflags & (US_FL_FIX_CAPACITY |
176 us->fflags |= US_FL_CAPACITY_HEURISTICS;
180 /* Disk-type devices use MODE SENSE(6) if the protocol
181 * (SubClass) is Transparent SCSI, otherwise they use
183 if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB)
184 sdev->use_10_for_ms = 1;
186 /* Many disks only accept MODE SENSE transfer lengths of
187 * 192 bytes (that's what Windows uses). */
188 sdev->use_192_bytes_for_3f = 1;
190 /* Some devices don't like MODE SENSE with page=0x3f,
191 * which is the command used for checking if a device
192 * is write-protected. Now that we tell the sd driver
193 * to do a 192-byte transfer with this command the
194 * majority of devices work fine, but a few still can't
195 * handle it. The sd driver will simply assume those
196 * devices are write-enabled. */
197 if (us->fflags & US_FL_NO_WP_DETECT)
198 sdev->skip_ms_page_3f = 1;
200 /* A number of devices have problems with MODE SENSE for
201 * page x08, so we will skip it. */
202 sdev->skip_ms_page_8 = 1;
204 /* Some disks return the total number of blocks in response
205 * to READ CAPACITY rather than the highest block number.
206 * If this device makes that mistake, tell the sd driver. */
207 if (us->fflags & US_FL_FIX_CAPACITY)
208 sdev->fix_capacity = 1;
210 /* A few disks have two indistinguishable version, one of
211 * which reports the correct capacity and the other does not.
212 * The sd driver has to guess which is the case. */
213 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
214 sdev->guess_capacity = 1;
216 /* Some devices cannot handle READ_CAPACITY_16 */
217 if (us->fflags & US_FL_NO_READ_CAPACITY_16)
218 sdev->no_read_capacity_16 = 1;
220 /* assume SPC3 or latter devices support sense size > 18 */
221 if (sdev->scsi_level > SCSI_SPC_2)
222 us->fflags |= US_FL_SANE_SENSE;
224 /* Some devices report a SCSI revision level above 2 but are
225 * unable to handle the REPORT LUNS command (for which
226 * support is mandatory at level 3). Since we already have
227 * a Get-Max-LUN request, we won't lose much by setting the
228 * revision level down to 2. The only devices that would be
229 * affected are those with sparse LUNs. */
230 if (sdev->scsi_level > SCSI_2)
231 sdev->sdev_target->scsi_level =
232 sdev->scsi_level = SCSI_2;
234 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
235 * Hardware Error) when any low-level error occurs,
236 * recoverable or not. Setting this flag tells the SCSI
237 * midlayer to retry such commands, which frequently will
238 * succeed and fix the error. The worst this can lead to
239 * is an occasional series of retries that will all fail. */
240 sdev->retry_hwerror = 1;
242 /* USB disks should allow restart. Some drives spin down
243 * automatically, requiring a START-STOP UNIT command. */
244 sdev->allow_restart = 1;
246 /* Some USB cardreaders have trouble reading an sdcard's last
247 * sector in a larger then 1 sector read, since the performance
248 * impact is negible we set this flag for all USB disks */
249 sdev->last_sector_bug = 1;
251 /* Enable last-sector hacks for single-target devices using
252 * the Bulk-only transport, unless we already know the
253 * capacity will be decremented or is correct. */
254 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
255 US_FL_SCM_MULT_TARG)) &&
256 us->protocol == USB_PR_BULK)
257 us->use_last_sector_hacks = 1;
260 /* Non-disk-type devices don't need to blacklist any pages
261 * or to force 192-byte transfer lengths for MODE SENSE.
262 * But they do need to use MODE SENSE(10). */
263 sdev->use_10_for_ms = 1;
265 /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
266 if (us->fflags & US_FL_NO_READ_DISC_INFO)
267 sdev->no_read_disc_info = 1;
270 /* The CB and CBI transports have no way to pass LUN values
271 * other than the bits in the second byte of a CDB. But those
272 * bits don't get set to the LUN value if the device reports
273 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
276 if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
277 sdev->scsi_level == SCSI_UNKNOWN)
280 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
281 * REMOVAL command, so suppress those commands. */
282 if (us->fflags & US_FL_NOT_LOCKABLE)
285 /* this is to satisfy the compiler, tho I don't think the
286 * return code is ever checked anywhere. */
290 /* queue a command */
291 /* This is always called with scsi_lock(host) held */
292 static int queuecommand_lck(struct scsi_cmnd *srb,
293 void (*done)(struct scsi_cmnd *))
295 struct us_data *us = host_to_us(srb->device->host);
297 US_DEBUGP("%s called\n", __func__);
299 /* check for state-transition errors */
300 if (us->srb != NULL) {
301 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
303 return SCSI_MLQUEUE_HOST_BUSY;
306 /* fail the command if we are disconnecting */
307 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
308 US_DEBUGP("Fail command during disconnect\n");
309 srb->result = DID_NO_CONNECT << 16;
314 /* enqueue the command and wake up the control thread */
315 srb->scsi_done = done;
317 complete(&us->cmnd_ready);
322 static DEF_SCSI_QCMD(queuecommand)
324 /***********************************************************************
325 * Error handling functions
326 ***********************************************************************/
328 /* Command timeout and abort */
329 static int command_abort(struct scsi_cmnd *srb)
331 struct us_data *us = host_to_us(srb->device->host);
333 US_DEBUGP("%s called\n", __func__);
335 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
336 * bits are protected by the host lock. */
337 scsi_lock(us_to_host(us));
339 /* Is this command still active? */
340 if (us->srb != srb) {
341 scsi_unlock(us_to_host(us));
342 US_DEBUGP ("-- nothing to abort\n");
346 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
347 * a device reset isn't already in progress (to avoid interfering
348 * with the reset). Note that we must retain the host lock while
349 * calling usb_stor_stop_transport(); otherwise it might interfere
350 * with an auto-reset that begins as soon as we release the lock. */
351 set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
352 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
353 set_bit(US_FLIDX_ABORTING, &us->dflags);
354 usb_stor_stop_transport(us);
356 scsi_unlock(us_to_host(us));
358 /* Wait for the aborted command to finish */
359 wait_for_completion(&us->notify);
363 /* This invokes the transport reset mechanism to reset the state of the
365 static int device_reset(struct scsi_cmnd *srb)
367 struct us_data *us = host_to_us(srb->device->host);
370 US_DEBUGP("%s called\n", __func__);
372 /* lock the device pointers and do the reset */
373 mutex_lock(&(us->dev_mutex));
374 result = us->transport_reset(us);
375 mutex_unlock(&us->dev_mutex);
377 return result < 0 ? FAILED : SUCCESS;
380 /* Simulate a SCSI bus reset by resetting the device's USB port. */
381 static int bus_reset(struct scsi_cmnd *srb)
383 struct us_data *us = host_to_us(srb->device->host);
386 US_DEBUGP("%s called\n", __func__);
387 result = usb_stor_port_reset(us);
388 return result < 0 ? FAILED : SUCCESS;
391 /* Report a driver-initiated device reset to the SCSI layer.
392 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
393 * The caller must own the SCSI host lock. */
394 void usb_stor_report_device_reset(struct us_data *us)
397 struct Scsi_Host *host = us_to_host(us);
399 scsi_report_device_reset(host, 0, 0);
400 if (us->fflags & US_FL_SCM_MULT_TARG) {
401 for (i = 1; i < host->max_id; ++i)
402 scsi_report_device_reset(host, 0, i);
406 /* Report a driver-initiated bus reset to the SCSI layer.
407 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
408 * The caller must not own the SCSI host lock. */
409 void usb_stor_report_bus_reset(struct us_data *us)
411 struct Scsi_Host *host = us_to_host(us);
414 scsi_report_bus_reset(host, 0);
418 /***********************************************************************
419 * /proc/scsi/ functions
420 ***********************************************************************/
422 /* we use this macro to help us write into the buffer */
424 #define SPRINTF(args...) \
425 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
427 static int proc_info (struct Scsi_Host *host, char *buffer,
428 char **start, off_t offset, int length, int inout)
430 struct us_data *us = host_to_us(host);
434 /* if someone is sending us data, just throw it away */
438 /* print the controller name */
439 SPRINTF(" Host scsi%d: usb-storage\n", host->host_no);
441 /* print product, vendor, and serial number strings */
442 if (us->pusb_dev->manufacturer)
443 string = us->pusb_dev->manufacturer;
444 else if (us->unusual_dev->vendorName)
445 string = us->unusual_dev->vendorName;
448 SPRINTF(" Vendor: %s\n", string);
449 if (us->pusb_dev->product)
450 string = us->pusb_dev->product;
451 else if (us->unusual_dev->productName)
452 string = us->unusual_dev->productName;
455 SPRINTF(" Product: %s\n", string);
456 if (us->pusb_dev->serial)
457 string = us->pusb_dev->serial;
460 SPRINTF("Serial Number: %s\n", string);
462 /* show the protocol and transport */
463 SPRINTF(" Protocol: %s\n", us->protocol_name);
464 SPRINTF(" Transport: %s\n", us->transport_name);
466 /* show the device flags */
467 if (pos < buffer + length) {
468 pos += sprintf(pos, " Quirks:");
470 #define US_FLAG(name, value) \
471 if (us->fflags & value) pos += sprintf(pos, " " #name);
479 * Calculate start of next buffer, and return value.
481 *start = buffer + offset;
483 if ((pos - buffer) < offset)
485 else if ((pos - buffer - offset) < length)
486 return (pos - buffer - offset);
491 /***********************************************************************
493 ***********************************************************************/
495 /* Output routine for the sysfs max_sectors file */
496 static ssize_t show_max_sectors(struct device *dev, struct device_attribute *attr, char *buf)
498 struct scsi_device *sdev = to_scsi_device(dev);
500 return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
503 /* Input routine for the sysfs max_sectors file */
504 static ssize_t store_max_sectors(struct device *dev, struct device_attribute *attr, const char *buf,
507 struct scsi_device *sdev = to_scsi_device(dev);
510 if (sscanf(buf, "%hu", &ms) > 0) {
511 blk_queue_max_hw_sectors(sdev->request_queue, ms);
517 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
520 static struct device_attribute *sysfs_device_attr_list[] = {
521 &dev_attr_max_sectors,
526 * this defines our host template, with which we'll allocate hosts
529 struct scsi_host_template usb_stor_host_template = {
530 /* basic userland interface stuff */
531 .name = "usb-storage",
532 .proc_name = "usb-storage",
533 .proc_info = proc_info,
536 /* command interface -- queued only */
537 .queuecommand = queuecommand,
539 /* error and abort handlers */
540 .eh_abort_handler = command_abort,
541 .eh_device_reset_handler = device_reset,
542 .eh_bus_reset_handler = bus_reset,
544 /* queue commands only, only one command per LUN */
548 /* unknown initiator id */
551 .slave_alloc = slave_alloc,
552 .slave_configure = slave_configure,
554 /* lots of sg segments can be handled */
555 .sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS,
557 /* limit the total size of a transfer to 120 KB */
560 /* merge commands... this seems to help performance, but
561 * periodically someone should test to see which setting is more
569 /* we do our own delay after a device or bus reset */
570 .skip_settle_delay = 1,
572 /* sysfs device attributes */
573 .sdev_attrs = sysfs_device_attr_list,
575 /* module management */
576 .module = THIS_MODULE
579 /* To Report "Illegal Request: Invalid Field in CDB */
580 unsigned char usb_stor_sense_invalidCDB[18] = {
581 [0] = 0x70, /* current error */
582 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
583 [7] = 0x0a, /* additional length */
584 [12] = 0x24 /* Invalid Field in CDB */
586 EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);