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 /* We can't put these settings in slave_alloc() because that gets
140 * called before the device type is known. Consequently these
141 * settings can't be overridden via the scsi devinfo mechanism. */
142 if (sdev->type == TYPE_DISK) {
144 /* Some vendors seem to put the READ CAPACITY bug into
145 * all their devices -- primarily makers of cell phones
146 * and digital cameras. Since these devices always use
147 * flash media and can be expected to have an even number
148 * of sectors, we will always enable the CAPACITY_HEURISTICS
149 * flag unless told otherwise. */
150 switch (le16_to_cpu(us->pusb_dev->descriptor.idVendor)) {
151 case VENDOR_ID_NOKIA:
152 case VENDOR_ID_NIKON:
153 case VENDOR_ID_MOTOROLA:
154 if (!(us->fflags & (US_FL_FIX_CAPACITY |
156 us->fflags |= US_FL_CAPACITY_HEURISTICS;
160 /* Disk-type devices use MODE SENSE(6) if the protocol
161 * (SubClass) is Transparent SCSI, otherwise they use
163 if (us->subclass != US_SC_SCSI && us->subclass != US_SC_CYP_ATACB)
164 sdev->use_10_for_ms = 1;
166 /* Many disks only accept MODE SENSE transfer lengths of
167 * 192 bytes (that's what Windows uses). */
168 sdev->use_192_bytes_for_3f = 1;
170 /* Some devices don't like MODE SENSE with page=0x3f,
171 * which is the command used for checking if a device
172 * is write-protected. Now that we tell the sd driver
173 * to do a 192-byte transfer with this command the
174 * majority of devices work fine, but a few still can't
175 * handle it. The sd driver will simply assume those
176 * devices are write-enabled. */
177 if (us->fflags & US_FL_NO_WP_DETECT)
178 sdev->skip_ms_page_3f = 1;
180 /* A number of devices have problems with MODE SENSE for
181 * page x08, so we will skip it. */
182 sdev->skip_ms_page_8 = 1;
184 /* Some disks return the total number of blocks in response
185 * to READ CAPACITY rather than the highest block number.
186 * If this device makes that mistake, tell the sd driver. */
187 if (us->fflags & US_FL_FIX_CAPACITY)
188 sdev->fix_capacity = 1;
190 /* A few disks have two indistinguishable version, one of
191 * which reports the correct capacity and the other does not.
192 * The sd driver has to guess which is the case. */
193 if (us->fflags & US_FL_CAPACITY_HEURISTICS)
194 sdev->guess_capacity = 1;
196 /* Some devices report a SCSI revision level above 2 but are
197 * unable to handle the REPORT LUNS command (for which
198 * support is mandatory at level 3). Since we already have
199 * a Get-Max-LUN request, we won't lose much by setting the
200 * revision level down to 2. The only devices that would be
201 * affected are those with sparse LUNs. */
202 if (sdev->scsi_level > SCSI_2)
203 sdev->sdev_target->scsi_level =
204 sdev->scsi_level = SCSI_2;
206 /* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
207 * Hardware Error) when any low-level error occurs,
208 * recoverable or not. Setting this flag tells the SCSI
209 * midlayer to retry such commands, which frequently will
210 * succeed and fix the error. The worst this can lead to
211 * is an occasional series of retries that will all fail. */
212 sdev->retry_hwerror = 1;
214 /* USB disks should allow restart. Some drives spin down
215 * automatically, requiring a START-STOP UNIT command. */
216 sdev->allow_restart = 1;
218 /* Some USB cardreaders have trouble reading an sdcard's last
219 * sector in a larger then 1 sector read, since the performance
220 * impact is negible we set this flag for all USB disks */
221 sdev->last_sector_bug = 1;
223 /* Enable last-sector hacks for single-target devices using
224 * the Bulk-only transport, unless we already know the
225 * capacity will be decremented or is correct. */
226 if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
227 US_FL_SCM_MULT_TARG)) &&
228 us->protocol == US_PR_BULK)
229 us->use_last_sector_hacks = 1;
232 /* Non-disk-type devices don't need to blacklist any pages
233 * or to force 192-byte transfer lengths for MODE SENSE.
234 * But they do need to use MODE SENSE(10). */
235 sdev->use_10_for_ms = 1;
238 /* The CB and CBI transports have no way to pass LUN values
239 * other than the bits in the second byte of a CDB. But those
240 * bits don't get set to the LUN value if the device reports
241 * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
244 if ((us->protocol == US_PR_CB || us->protocol == US_PR_CBI) &&
245 sdev->scsi_level == SCSI_UNKNOWN)
248 /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
249 * REMOVAL command, so suppress those commands. */
250 if (us->fflags & US_FL_NOT_LOCKABLE)
253 /* this is to satisfy the compiler, tho I don't think the
254 * return code is ever checked anywhere. */
258 /* queue a command */
259 /* This is always called with scsi_lock(host) held */
260 static int queuecommand(struct scsi_cmnd *srb,
261 void (*done)(struct scsi_cmnd *))
263 struct us_data *us = host_to_us(srb->device->host);
265 US_DEBUGP("%s called\n", __func__);
267 /* check for state-transition errors */
268 if (us->srb != NULL) {
269 printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
271 return SCSI_MLQUEUE_HOST_BUSY;
274 /* fail the command if we are disconnecting */
275 if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
276 US_DEBUGP("Fail command during disconnect\n");
277 srb->result = DID_NO_CONNECT << 16;
282 /* enqueue the command and wake up the control thread */
283 srb->scsi_done = done;
285 complete(&us->cmnd_ready);
290 /***********************************************************************
291 * Error handling functions
292 ***********************************************************************/
294 /* Command timeout and abort */
295 static int command_abort(struct scsi_cmnd *srb)
297 struct us_data *us = host_to_us(srb->device->host);
299 US_DEBUGP("%s called\n", __func__);
301 /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
302 * bits are protected by the host lock. */
303 scsi_lock(us_to_host(us));
305 /* Is this command still active? */
306 if (us->srb != srb) {
307 scsi_unlock(us_to_host(us));
308 US_DEBUGP ("-- nothing to abort\n");
312 /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
313 * a device reset isn't already in progress (to avoid interfering
314 * with the reset). Note that we must retain the host lock while
315 * calling usb_stor_stop_transport(); otherwise it might interfere
316 * with an auto-reset that begins as soon as we release the lock. */
317 set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
318 if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
319 set_bit(US_FLIDX_ABORTING, &us->dflags);
320 usb_stor_stop_transport(us);
322 scsi_unlock(us_to_host(us));
324 /* Wait for the aborted command to finish */
325 wait_for_completion(&us->notify);
329 /* This invokes the transport reset mechanism to reset the state of the
331 static int device_reset(struct scsi_cmnd *srb)
333 struct us_data *us = host_to_us(srb->device->host);
336 US_DEBUGP("%s called\n", __func__);
338 /* lock the device pointers and do the reset */
339 mutex_lock(&(us->dev_mutex));
340 result = us->transport_reset(us);
341 mutex_unlock(&us->dev_mutex);
343 return result < 0 ? FAILED : SUCCESS;
346 /* Simulate a SCSI bus reset by resetting the device's USB port. */
347 static int bus_reset(struct scsi_cmnd *srb)
349 struct us_data *us = host_to_us(srb->device->host);
352 US_DEBUGP("%s called\n", __func__);
353 result = usb_stor_port_reset(us);
354 return result < 0 ? FAILED : SUCCESS;
357 /* Report a driver-initiated device reset to the SCSI layer.
358 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
359 * The caller must own the SCSI host lock. */
360 void usb_stor_report_device_reset(struct us_data *us)
363 struct Scsi_Host *host = us_to_host(us);
365 scsi_report_device_reset(host, 0, 0);
366 if (us->fflags & US_FL_SCM_MULT_TARG) {
367 for (i = 1; i < host->max_id; ++i)
368 scsi_report_device_reset(host, 0, i);
372 /* Report a driver-initiated bus reset to the SCSI layer.
373 * Calling this for a SCSI-initiated reset is unnecessary but harmless.
374 * The caller must not own the SCSI host lock. */
375 void usb_stor_report_bus_reset(struct us_data *us)
377 struct Scsi_Host *host = us_to_host(us);
380 scsi_report_bus_reset(host, 0);
384 /***********************************************************************
385 * /proc/scsi/ functions
386 ***********************************************************************/
388 /* we use this macro to help us write into the buffer */
390 #define SPRINTF(args...) \
391 do { if (pos < buffer+length) pos += sprintf(pos, ## args); } while (0)
393 static int proc_info (struct Scsi_Host *host, char *buffer,
394 char **start, off_t offset, int length, int inout)
396 struct us_data *us = host_to_us(host);
400 /* if someone is sending us data, just throw it away */
404 /* print the controller name */
405 SPRINTF(" Host scsi%d: usb-storage\n", host->host_no);
407 /* print product, vendor, and serial number strings */
408 if (us->pusb_dev->manufacturer)
409 string = us->pusb_dev->manufacturer;
410 else if (us->unusual_dev->vendorName)
411 string = us->unusual_dev->vendorName;
414 SPRINTF(" Vendor: %s\n", string);
415 if (us->pusb_dev->product)
416 string = us->pusb_dev->product;
417 else if (us->unusual_dev->productName)
418 string = us->unusual_dev->productName;
421 SPRINTF(" Product: %s\n", string);
422 if (us->pusb_dev->serial)
423 string = us->pusb_dev->serial;
426 SPRINTF("Serial Number: %s\n", string);
428 /* show the protocol and transport */
429 SPRINTF(" Protocol: %s\n", us->protocol_name);
430 SPRINTF(" Transport: %s\n", us->transport_name);
432 /* show the device flags */
433 if (pos < buffer + length) {
434 pos += sprintf(pos, " Quirks:");
436 #define US_FLAG(name, value) \
437 if (us->fflags & value) pos += sprintf(pos, " " #name);
445 * Calculate start of next buffer, and return value.
447 *start = buffer + offset;
449 if ((pos - buffer) < offset)
451 else if ((pos - buffer - offset) < length)
452 return (pos - buffer - offset);
457 /***********************************************************************
459 ***********************************************************************/
461 /* Output routine for the sysfs max_sectors file */
462 static ssize_t show_max_sectors(struct device *dev, struct device_attribute *attr, char *buf)
464 struct scsi_device *sdev = to_scsi_device(dev);
466 return sprintf(buf, "%u\n", sdev->request_queue->max_sectors);
469 /* Input routine for the sysfs max_sectors file */
470 static ssize_t store_max_sectors(struct device *dev, struct device_attribute *attr, const char *buf,
473 struct scsi_device *sdev = to_scsi_device(dev);
476 if (sscanf(buf, "%hu", &ms) > 0 && ms <= SCSI_DEFAULT_MAX_SECTORS) {
477 blk_queue_max_sectors(sdev->request_queue, ms);
483 static DEVICE_ATTR(max_sectors, S_IRUGO | S_IWUSR, show_max_sectors,
486 static struct device_attribute *sysfs_device_attr_list[] = {
487 &dev_attr_max_sectors,
492 * this defines our host template, with which we'll allocate hosts
495 struct scsi_host_template usb_stor_host_template = {
496 /* basic userland interface stuff */
497 .name = "usb-storage",
498 .proc_name = "usb-storage",
499 .proc_info = proc_info,
502 /* command interface -- queued only */
503 .queuecommand = queuecommand,
505 /* error and abort handlers */
506 .eh_abort_handler = command_abort,
507 .eh_device_reset_handler = device_reset,
508 .eh_bus_reset_handler = bus_reset,
510 /* queue commands only, only one command per LUN */
514 /* unknown initiator id */
517 .slave_alloc = slave_alloc,
518 .slave_configure = slave_configure,
520 /* lots of sg segments can be handled */
521 .sg_tablesize = SG_ALL,
523 /* limit the total size of a transfer to 120 KB */
526 /* merge commands... this seems to help performance, but
527 * periodically someone should test to see which setting is more
535 /* we do our own delay after a device or bus reset */
536 .skip_settle_delay = 1,
538 /* sysfs device attributes */
539 .sdev_attrs = sysfs_device_attr_list,
541 /* module management */
542 .module = THIS_MODULE
545 /* To Report "Illegal Request: Invalid Field in CDB */
546 unsigned char usb_stor_sense_invalidCDB[18] = {
547 [0] = 0x70, /* current error */
548 [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
549 [7] = 0x0a, /* additional length */
550 [12] = 0x24 /* Invalid Field in CDB */