Branch data Line data Source code
1 : : /* Driver for USB Mass Storage compliant devices
2 : : * SCSI layer glue code
3 : : *
4 : : * Current development and maintenance by:
5 : : * (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
6 : : *
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)
10 : : *
11 : : * Initial work by:
12 : : * (c) 1999 Michael Gee (michael@linuxspecific.com)
13 : : *
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.
19 : : *
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.
24 : : *
25 : : * Also, for certain devices, the interrupt endpoint is used to convey
26 : : * status of a command.
27 : : *
28 : : * Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
29 : : * information about this driver.
30 : : *
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
34 : : * later version.
35 : : *
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.
40 : : *
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.
44 : : */
45 : :
46 : : #include <linux/module.h>
47 : : #include <linux/mutex.h>
48 : :
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>
54 : :
55 : : #include "usb.h"
56 : : #include "scsiglue.h"
57 : : #include "debug.h"
58 : : #include "transport.h"
59 : : #include "protocol.h"
60 : :
61 : : /* Vendor IDs for companies that seem to include the READ CAPACITY bug
62 : : * in all their devices
63 : : */
64 : : #define VENDOR_ID_NOKIA 0x0421
65 : : #define VENDOR_ID_NIKON 0x04b0
66 : : #define VENDOR_ID_PENTAX 0x0a17
67 : : #define VENDOR_ID_MOTOROLA 0x22b8
68 : :
69 : : /***********************************************************************
70 : : * Host functions
71 : : ***********************************************************************/
72 : :
73 : 0 : static const char* host_info(struct Scsi_Host *host)
74 : : {
75 : : struct us_data *us = host_to_us(host);
76 : 0 : return us->scsi_name;
77 : : }
78 : :
79 : 0 : static int slave_alloc (struct scsi_device *sdev)
80 : : {
81 : 0 : struct us_data *us = host_to_us(sdev->host);
82 : :
83 : : /*
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
86 : : * less than 36 bytes.
87 : : */
88 : 0 : sdev->inquiry_len = 36;
89 : :
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.
100 : : *
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.
104 : : */
105 : 0 : blk_queue_update_dma_alignment(sdev->request_queue, (512 - 1));
106 : :
107 : : /* Tell the SCSI layer if we know there is more than one LUN */
108 [ # # ][ # # ]: 0 : if (us->protocol == USB_PR_BULK && us->max_lun > 0)
109 : 0 : sdev->sdev_bflags |= BLIST_FORCELUN;
110 : :
111 : 0 : return 0;
112 : : }
113 : :
114 : 0 : static int slave_configure(struct scsi_device *sdev)
115 : : {
116 : 0 : struct us_data *us = host_to_us(sdev->host);
117 : :
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).
121 : : */
122 [ # # ]: 0 : if (us->fflags & (US_FL_MAX_SECTORS_64 | US_FL_MAX_SECTORS_MIN)) {
123 : : unsigned int max_sectors = 64;
124 : :
125 [ # # ]: 0 : if (us->fflags & US_FL_MAX_SECTORS_MIN)
126 : : max_sectors = PAGE_CACHE_SIZE >> 9;
127 [ # # ]: 0 : if (queue_max_hw_sectors(sdev->request_queue) > max_sectors)
128 : 0 : blk_queue_max_hw_sectors(sdev->request_queue,
129 : : max_sectors);
130 [ # # ]: 0 : } 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.
134 : : */
135 : 0 : blk_queue_max_hw_sectors(sdev->request_queue, 0x7FFFFF);
136 : : }
137 : :
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.
142 : : */
143 [ # # ]: 0 : if (!us->pusb_dev->bus->controller->dma_mask)
144 : 0 : blk_queue_bounce_limit(sdev->request_queue, BLK_BOUNCE_HIGH);
145 : :
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 [ # # ]: 0 : if (sdev->type == TYPE_DISK) {
150 : :
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 [ # # ]: 0 : 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 [ # # ]: 0 : if (!(us->fflags & (US_FL_FIX_CAPACITY |
163 : : US_FL_CAPACITY_OK)))
164 : 0 : us->fflags |= US_FL_CAPACITY_HEURISTICS;
165 : : break;
166 : : }
167 : :
168 : : /* Disk-type devices use MODE SENSE(6) if the protocol
169 : : * (SubClass) is Transparent SCSI, otherwise they use
170 : : * MODE SENSE(10). */
171 [ # # ]: 0 : if (us->subclass != USB_SC_SCSI && us->subclass != USB_SC_CYP_ATACB)
172 : 0 : sdev->use_10_for_ms = 1;
173 : :
174 : : /* Many disks only accept MODE SENSE transfer lengths of
175 : : * 192 bytes (that's what Windows uses). */
176 : 0 : sdev->use_192_bytes_for_3f = 1;
177 : :
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 [ # # ]: 0 : if (us->fflags & US_FL_NO_WP_DETECT)
186 : 0 : sdev->skip_ms_page_3f = 1;
187 : :
188 : : /* A number of devices have problems with MODE SENSE for
189 : : * page x08, so we will skip it. */
190 : 0 : sdev->skip_ms_page_8 = 1;
191 : :
192 : : /* Some devices don't handle VPD pages correctly */
193 : 0 : sdev->skip_vpd_pages = 1;
194 : :
195 : : /* Do not attempt to use REPORT SUPPORTED OPERATION CODES */
196 : 0 : sdev->no_report_opcodes = 1;
197 : :
198 : : /* Do not attempt to use WRITE SAME */
199 : 0 : sdev->no_write_same = 1;
200 : :
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 [ # # ]: 0 : if (us->fflags & US_FL_FIX_CAPACITY)
205 : 0 : sdev->fix_capacity = 1;
206 : :
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 [ # # ]: 0 : if (us->fflags & US_FL_CAPACITY_HEURISTICS)
211 : 0 : sdev->guess_capacity = 1;
212 : :
213 : : /* Some devices cannot handle READ_CAPACITY_16 */
214 [ # # ]: 0 : if (us->fflags & US_FL_NO_READ_CAPACITY_16)
215 : 0 : sdev->no_read_capacity_16 = 1;
216 : :
217 : : /*
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
222 : : */
223 [ # # ]: 0 : if (!(us->fflags & US_FL_NEEDS_CAP16))
224 : 0 : sdev->try_rc_10_first = 1;
225 : :
226 : : /* assume SPC3 or latter devices support sense size > 18 */
227 [ # # ]: 0 : if (sdev->scsi_level > SCSI_SPC_2)
228 : 0 : us->fflags |= US_FL_SANE_SENSE;
229 : :
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 : 0 : sdev->retry_hwerror = 1;
237 : :
238 : : /* USB disks should allow restart. Some drives spin down
239 : : * automatically, requiring a START-STOP UNIT command. */
240 : 0 : sdev->allow_restart = 1;
241 : :
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 : 0 : sdev->last_sector_bug = 1;
246 : :
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 [ # # ]: 0 : if (!(us->fflags & (US_FL_FIX_CAPACITY | US_FL_CAPACITY_OK |
251 [ # # ]: 0 : US_FL_SCM_MULT_TARG)) &&
252 : 0 : us->protocol == USB_PR_BULK)
253 : 0 : us->use_last_sector_hacks = 1;
254 : :
255 : : /* Check if write cache default on flag is set or not */
256 [ # # ]: 0 : if (us->fflags & US_FL_WRITE_CACHE)
257 : 0 : sdev->wce_default_on = 1;
258 : :
259 : : } else {
260 : :
261 : : /* Non-disk-type devices don't need to blacklist any pages
262 : : * or to force 192-byte transfer lengths for MODE SENSE.
263 : : * But they do need to use MODE SENSE(10). */
264 : 0 : sdev->use_10_for_ms = 1;
265 : :
266 : : /* Some (fake) usb cdrom devices don't like READ_DISC_INFO */
267 [ # # ]: 0 : if (us->fflags & US_FL_NO_READ_DISC_INFO)
268 : 0 : sdev->no_read_disc_info = 1;
269 : : }
270 : :
271 : : /* The CB and CBI transports have no way to pass LUN values
272 : : * other than the bits in the second byte of a CDB. But those
273 : : * bits don't get set to the LUN value if the device reports
274 : : * scsi_level == 0 (UNKNOWN). Hence such devices must necessarily
275 : : * be single-LUN.
276 : : */
277 [ # # ][ # # ]: 0 : if ((us->protocol == USB_PR_CB || us->protocol == USB_PR_CBI) &&
278 : 0 : sdev->scsi_level == SCSI_UNKNOWN)
279 : 0 : us->max_lun = 0;
280 : :
281 : : /* Some devices choke when they receive a PREVENT-ALLOW MEDIUM
282 : : * REMOVAL command, so suppress those commands. */
283 [ # # ]: 0 : if (us->fflags & US_FL_NOT_LOCKABLE)
284 : 0 : sdev->lockable = 0;
285 : :
286 : : /* this is to satisfy the compiler, tho I don't think the
287 : : * return code is ever checked anywhere. */
288 : 0 : return 0;
289 : : }
290 : :
291 : 0 : static int target_alloc(struct scsi_target *starget)
292 : : {
293 : 0 : struct us_data *us = host_to_us(dev_to_shost(starget->dev.parent));
294 : :
295 : : /*
296 : : * Some USB drives don't support REPORT LUNS, even though they
297 : : * report a SCSI revision level above 2. Tell the SCSI layer
298 : : * not to issue that command; it will perform a normal sequential
299 : : * scan instead.
300 : : */
301 : 0 : starget->no_report_luns = 1;
302 : :
303 : : /*
304 : : * The UFI spec treats the Peripheral Qualifier bits in an
305 : : * INQUIRY result as reserved and requires devices to set them
306 : : * to 0. However the SCSI spec requires these bits to be set
307 : : * to 3 to indicate when a LUN is not present.
308 : : *
309 : : * Let the scanning code know if this target merely sets
310 : : * Peripheral Device Type to 0x1f to indicate no LUN.
311 : : */
312 [ # # ]: 0 : if (us->subclass == USB_SC_UFI)
313 : 0 : starget->pdt_1f_for_no_lun = 1;
314 : :
315 : 0 : return 0;
316 : : }
317 : :
318 : : /* queue a command */
319 : : /* This is always called with scsi_lock(host) held */
320 : 0 : static int queuecommand_lck(struct scsi_cmnd *srb,
321 : : void (*done)(struct scsi_cmnd *))
322 : : {
323 : 401979 : struct us_data *us = host_to_us(srb->device->host);
324 : :
325 : : /* check for state-transition errors */
326 [ - + ]: 401979 : if (us->srb != NULL) {
327 : 0 : printk(KERN_ERR USB_STORAGE "Error in %s: us->srb = %p\n",
328 : : __func__, us->srb);
329 : 0 : return SCSI_MLQUEUE_HOST_BUSY;
330 : : }
331 : :
332 : : /* fail the command if we are disconnecting */
333 [ - + ]: 401979 : if (test_bit(US_FLIDX_DISCONNECTING, &us->dflags)) {
334 : : usb_stor_dbg(us, "Fail command during disconnect\n");
335 : 0 : srb->result = DID_NO_CONNECT << 16;
336 : 0 : done(srb);
337 : 0 : return 0;
338 : : }
339 : :
340 : : /* enqueue the command and wake up the control thread */
341 : 401979 : srb->scsi_done = done;
342 : 401979 : us->srb = srb;
343 : 401979 : complete(&us->cmnd_ready);
344 : :
345 : 401979 : return 0;
346 : : }
347 : :
348 : 401979 : static DEF_SCSI_QCMD(queuecommand)
349 : :
350 : : /***********************************************************************
351 : : * Error handling functions
352 : : ***********************************************************************/
353 : :
354 : : /* Command timeout and abort */
355 : 0 : static int command_abort(struct scsi_cmnd *srb)
356 : : {
357 : 0 : struct us_data *us = host_to_us(srb->device->host);
358 : :
359 : : usb_stor_dbg(us, "%s called\n", __func__);
360 : :
361 : : /* us->srb together with the TIMED_OUT, RESETTING, and ABORTING
362 : : * bits are protected by the host lock. */
363 : 0 : scsi_lock(us_to_host(us));
364 : :
365 : : /* Is this command still active? */
366 [ # # ]: 0 : if (us->srb != srb) {
367 : 0 : scsi_unlock(us_to_host(us));
368 : : usb_stor_dbg(us, "-- nothing to abort\n");
369 : 0 : return FAILED;
370 : : }
371 : :
372 : : /* Set the TIMED_OUT bit. Also set the ABORTING bit, but only if
373 : : * a device reset isn't already in progress (to avoid interfering
374 : : * with the reset). Note that we must retain the host lock while
375 : : * calling usb_stor_stop_transport(); otherwise it might interfere
376 : : * with an auto-reset that begins as soon as we release the lock. */
377 : 0 : set_bit(US_FLIDX_TIMED_OUT, &us->dflags);
378 [ # # ]: 0 : if (!test_bit(US_FLIDX_RESETTING, &us->dflags)) {
379 : 0 : set_bit(US_FLIDX_ABORTING, &us->dflags);
380 : 0 : usb_stor_stop_transport(us);
381 : : }
382 : 0 : scsi_unlock(us_to_host(us));
383 : :
384 : : /* Wait for the aborted command to finish */
385 : 0 : wait_for_completion(&us->notify);
386 : 0 : return SUCCESS;
387 : : }
388 : :
389 : : /* This invokes the transport reset mechanism to reset the state of the
390 : : * device */
391 : 0 : static int device_reset(struct scsi_cmnd *srb)
392 : : {
393 : 0 : struct us_data *us = host_to_us(srb->device->host);
394 : : int result;
395 : :
396 : : usb_stor_dbg(us, "%s called\n", __func__);
397 : :
398 : : /* lock the device pointers and do the reset */
399 : 0 : mutex_lock(&(us->dev_mutex));
400 : 0 : result = us->transport_reset(us);
401 : 0 : mutex_unlock(&us->dev_mutex);
402 : :
403 [ # # ]: 0 : return result < 0 ? FAILED : SUCCESS;
404 : : }
405 : :
406 : : /* Simulate a SCSI bus reset by resetting the device's USB port. */
407 : 0 : static int bus_reset(struct scsi_cmnd *srb)
408 : : {
409 : 0 : struct us_data *us = host_to_us(srb->device->host);
410 : : int result;
411 : :
412 : : usb_stor_dbg(us, "%s called\n", __func__);
413 : :
414 : 0 : result = usb_stor_port_reset(us);
415 [ # # ]: 0 : return result < 0 ? FAILED : SUCCESS;
416 : : }
417 : :
418 : : /* Report a driver-initiated device reset to the SCSI layer.
419 : : * Calling this for a SCSI-initiated reset is unnecessary but harmless.
420 : : * The caller must own the SCSI host lock. */
421 : 0 : void usb_stor_report_device_reset(struct us_data *us)
422 : : {
423 : : int i;
424 : 0 : struct Scsi_Host *host = us_to_host(us);
425 : :
426 : 0 : scsi_report_device_reset(host, 0, 0);
427 [ # # ]: 0 : if (us->fflags & US_FL_SCM_MULT_TARG) {
428 [ # # ]: 0 : for (i = 1; i < host->max_id; ++i)
429 : 0 : scsi_report_device_reset(host, 0, i);
430 : : }
431 : 0 : }
432 : :
433 : : /* Report a driver-initiated bus reset to the SCSI layer.
434 : : * Calling this for a SCSI-initiated reset is unnecessary but harmless.
435 : : * The caller must not own the SCSI host lock. */
436 : 0 : void usb_stor_report_bus_reset(struct us_data *us)
437 : : {
438 : 0 : struct Scsi_Host *host = us_to_host(us);
439 : :
440 : 0 : scsi_lock(host);
441 : 0 : scsi_report_bus_reset(host, 0);
442 : 0 : scsi_unlock(host);
443 : 0 : }
444 : :
445 : : /***********************************************************************
446 : : * /proc/scsi/ functions
447 : : ***********************************************************************/
448 : :
449 : 0 : static int write_info(struct Scsi_Host *host, char *buffer, int length)
450 : : {
451 : : /* if someone is sending us data, just throw it away */
452 : 0 : return length;
453 : : }
454 : :
455 : : /* we use this macro to help us write into the buffer */
456 : : #undef SPRINTF
457 : : #define SPRINTF(args...) seq_printf(m, ## args)
458 : :
459 : 0 : static int show_info (struct seq_file *m, struct Scsi_Host *host)
460 : : {
461 : : struct us_data *us = host_to_us(host);
462 : : const char *string;
463 : :
464 : : /* print the controller name */
465 : 1 : SPRINTF(" Host scsi%d: usb-storage\n", host->host_no);
466 : :
467 : : /* print product, vendor, and serial number strings */
468 [ - + ]: 1 : if (us->pusb_dev->manufacturer)
469 : : string = us->pusb_dev->manufacturer;
470 [ # # ]: 0 : else if (us->unusual_dev->vendorName)
471 : : string = us->unusual_dev->vendorName;
472 : : else
473 : : string = "Unknown";
474 : 1 : SPRINTF(" Vendor: %s\n", string);
475 [ - + ]: 1 : if (us->pusb_dev->product)
476 : : string = us->pusb_dev->product;
477 [ # # ]: 0 : else if (us->unusual_dev->productName)
478 : : string = us->unusual_dev->productName;
479 : : else
480 : : string = "Unknown";
481 : 1 : SPRINTF(" Product: %s\n", string);
482 [ + - ]: 1 : if (us->pusb_dev->serial)
483 : : string = us->pusb_dev->serial;
484 : : else
485 : : string = "None";
486 : 1 : SPRINTF("Serial Number: %s\n", string);
487 : :
488 : : /* show the protocol and transport */
489 : 1 : SPRINTF(" Protocol: %s\n", us->protocol_name);
490 : 1 : SPRINTF(" Transport: %s\n", us->transport_name);
491 : :
492 : : /* show the device flags */
493 : 1 : SPRINTF(" Quirks:");
494 : :
495 : : #define US_FLAG(name, value) \
496 : : if (us->fflags & value) seq_printf(m, " " #name);
497 [ - + ][ - + ]: 1 : US_DO_ALL_FLAGS
[ - + ][ - + ]
[ - + ][ - + ]
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[ - + ][ - + ]
[ - + ][ - + ]
[ - + ][ - + ]
[ - + ][ - + ]
[ - + ][ - + ]
[ - + ][ - + ]
[ - + ][ - + ]
[ - + ]
498 : : #undef US_FLAG
499 : 1 : seq_putc(m, '\n');
500 : 1 : return 0;
501 : : }
502 : :
503 : : /***********************************************************************
504 : : * Sysfs interface
505 : : ***********************************************************************/
506 : :
507 : : /* Output routine for the sysfs max_sectors file */
508 : 0 : static ssize_t max_sectors_show(struct device *dev, struct device_attribute *attr, char *buf)
509 : : {
510 : : struct scsi_device *sdev = to_scsi_device(dev);
511 : :
512 : 0 : return sprintf(buf, "%u\n", queue_max_hw_sectors(sdev->request_queue));
513 : : }
514 : :
515 : : /* Input routine for the sysfs max_sectors file */
516 : 0 : static ssize_t max_sectors_store(struct device *dev, struct device_attribute *attr, const char *buf,
517 : : size_t count)
518 : : {
519 : : struct scsi_device *sdev = to_scsi_device(dev);
520 : : unsigned short ms;
521 : :
522 [ # # ]: 0 : if (sscanf(buf, "%hu", &ms) > 0) {
523 : 0 : blk_queue_max_hw_sectors(sdev->request_queue, ms);
524 : 0 : return count;
525 : : }
526 : : return -EINVAL;
527 : : }
528 : : static DEVICE_ATTR_RW(max_sectors);
529 : :
530 : : static struct device_attribute *sysfs_device_attr_list[] = {
531 : : &dev_attr_max_sectors,
532 : : NULL,
533 : : };
534 : :
535 : : /*
536 : : * this defines our host template, with which we'll allocate hosts
537 : : */
538 : :
539 : : struct scsi_host_template usb_stor_host_template = {
540 : : /* basic userland interface stuff */
541 : : .name = "usb-storage",
542 : : .proc_name = "usb-storage",
543 : : .show_info = show_info,
544 : : .write_info = write_info,
545 : : .info = host_info,
546 : :
547 : : /* command interface -- queued only */
548 : : .queuecommand = queuecommand,
549 : :
550 : : /* error and abort handlers */
551 : : .eh_abort_handler = command_abort,
552 : : .eh_device_reset_handler = device_reset,
553 : : .eh_bus_reset_handler = bus_reset,
554 : :
555 : : /* queue commands only, only one command per LUN */
556 : : .can_queue = 1,
557 : : .cmd_per_lun = 1,
558 : :
559 : : /* unknown initiator id */
560 : : .this_id = -1,
561 : :
562 : : .slave_alloc = slave_alloc,
563 : : .slave_configure = slave_configure,
564 : : .target_alloc = target_alloc,
565 : :
566 : : /* lots of sg segments can be handled */
567 : : .sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS,
568 : :
569 : : /* limit the total size of a transfer to 120 KB */
570 : : .max_sectors = 240,
571 : :
572 : : /* merge commands... this seems to help performance, but
573 : : * periodically someone should test to see which setting is more
574 : : * optimal.
575 : : */
576 : : .use_clustering = 1,
577 : :
578 : : /* emulated HBA */
579 : : .emulated = 1,
580 : :
581 : : /* we do our own delay after a device or bus reset */
582 : : .skip_settle_delay = 1,
583 : :
584 : : /* sysfs device attributes */
585 : : .sdev_attrs = sysfs_device_attr_list,
586 : :
587 : : /* module management */
588 : : .module = THIS_MODULE
589 : : };
590 : :
591 : : /* To Report "Illegal Request: Invalid Field in CDB */
592 : : unsigned char usb_stor_sense_invalidCDB[18] = {
593 : : [0] = 0x70, /* current error */
594 : : [2] = ILLEGAL_REQUEST, /* Illegal Request = 0x05 */
595 : : [7] = 0x0a, /* additional length */
596 : : [12] = 0x24 /* Invalid Field in CDB */
597 : : };
598 : : EXPORT_SYMBOL_GPL(usb_stor_sense_invalidCDB);
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