![Alan Stern](/assets/img/avatar_default.png)
The 8020i protocol (also 8070i and QIC-157) uses 12-byte commands; shorter commands must be padded. Simon Detheridge reports that his 3-TB USB disk drive claims to use the 8020i protocol (which is normally meant for ATAPI devices like CD drives), and because of its large size, the disk drive requires the use of 16-byte commands. However the usb_stor_pad12_command() routine in usb-storage always sets the command length to 12, making the drive impossible to use. Since the SFF-8020i specification allows for 16-byte commands in future extensions, we may as well accept them. This patch (as1490) changes usb_stor_pad12_command() to leave commands larger than 12 bytes alone rather than truncating them. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Tested-by: Simon Detheridge <simon@widgit.com> CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
221 lines
6.9 KiB
C
221 lines
6.9 KiB
C
/* Driver for USB Mass Storage compliant devices
|
|
*
|
|
* Current development and maintenance by:
|
|
* (c) 1999-2002 Matthew Dharm (mdharm-usb@one-eyed-alien.net)
|
|
*
|
|
* Developed with the assistance of:
|
|
* (c) 2000 David L. Brown, Jr. (usb-storage@davidb.org)
|
|
* (c) 2002 Alan Stern (stern@rowland.org)
|
|
*
|
|
* Initial work by:
|
|
* (c) 1999 Michael Gee (michael@linuxspecific.com)
|
|
*
|
|
* This driver is based on the 'USB Mass Storage Class' document. This
|
|
* describes in detail the protocol used to communicate with such
|
|
* devices. Clearly, the designers had SCSI and ATAPI commands in
|
|
* mind when they created this document. The commands are all very
|
|
* similar to commands in the SCSI-II and ATAPI specifications.
|
|
*
|
|
* It is important to note that in a number of cases this class
|
|
* exhibits class-specific exemptions from the USB specification.
|
|
* Notably the usage of NAK, STALL and ACK differs from the norm, in
|
|
* that they are used to communicate wait, failed and OK on commands.
|
|
*
|
|
* Also, for certain devices, the interrupt endpoint is used to convey
|
|
* status of a command.
|
|
*
|
|
* Please see http://www.one-eyed-alien.net/~mdharm/linux-usb for more
|
|
* information about this driver.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it
|
|
* under the terms of the GNU General Public License as published by the
|
|
* Free Software Foundation; either version 2, or (at your option) any
|
|
* later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
* General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
#include <linux/highmem.h>
|
|
#include <linux/export.h>
|
|
#include <scsi/scsi.h>
|
|
#include <scsi/scsi_cmnd.h>
|
|
|
|
#include "usb.h"
|
|
#include "protocol.h"
|
|
#include "debug.h"
|
|
#include "scsiglue.h"
|
|
#include "transport.h"
|
|
|
|
/***********************************************************************
|
|
* Protocol routines
|
|
***********************************************************************/
|
|
|
|
void usb_stor_pad12_command(struct scsi_cmnd *srb, struct us_data *us)
|
|
{
|
|
/*
|
|
* Pad the SCSI command with zeros out to 12 bytes. If the
|
|
* command already is 12 bytes or longer, leave it alone.
|
|
*
|
|
* NOTE: This only works because a scsi_cmnd struct field contains
|
|
* a unsigned char cmnd[16], so we know we have storage available
|
|
*/
|
|
for (; srb->cmd_len<12; srb->cmd_len++)
|
|
srb->cmnd[srb->cmd_len] = 0;
|
|
|
|
/* send the command to the transport layer */
|
|
usb_stor_invoke_transport(srb, us);
|
|
}
|
|
|
|
void usb_stor_ufi_command(struct scsi_cmnd *srb, struct us_data *us)
|
|
{
|
|
/* fix some commands -- this is a form of mode translation
|
|
* UFI devices only accept 12 byte long commands
|
|
*
|
|
* NOTE: This only works because a scsi_cmnd struct field contains
|
|
* a unsigned char cmnd[16], so we know we have storage available
|
|
*/
|
|
|
|
/* Pad the ATAPI command with zeros */
|
|
for (; srb->cmd_len<12; srb->cmd_len++)
|
|
srb->cmnd[srb->cmd_len] = 0;
|
|
|
|
/* set command length to 12 bytes (this affects the transport layer) */
|
|
srb->cmd_len = 12;
|
|
|
|
/* XXX We should be constantly re-evaluating the need for these */
|
|
|
|
/* determine the correct data length for these commands */
|
|
switch (srb->cmnd[0]) {
|
|
|
|
/* for INQUIRY, UFI devices only ever return 36 bytes */
|
|
case INQUIRY:
|
|
srb->cmnd[4] = 36;
|
|
break;
|
|
|
|
/* again, for MODE_SENSE_10, we get the minimum (8) */
|
|
case MODE_SENSE_10:
|
|
srb->cmnd[7] = 0;
|
|
srb->cmnd[8] = 8;
|
|
break;
|
|
|
|
/* for REQUEST_SENSE, UFI devices only ever return 18 bytes */
|
|
case REQUEST_SENSE:
|
|
srb->cmnd[4] = 18;
|
|
break;
|
|
} /* end switch on cmnd[0] */
|
|
|
|
/* send the command to the transport layer */
|
|
usb_stor_invoke_transport(srb, us);
|
|
}
|
|
|
|
void usb_stor_transparent_scsi_command(struct scsi_cmnd *srb,
|
|
struct us_data *us)
|
|
{
|
|
/* send the command to the transport layer */
|
|
usb_stor_invoke_transport(srb, us);
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_stor_transparent_scsi_command);
|
|
|
|
/***********************************************************************
|
|
* Scatter-gather transfer buffer access routines
|
|
***********************************************************************/
|
|
|
|
/* Copy a buffer of length buflen to/from the srb's transfer buffer.
|
|
* Update the **sgptr and *offset variables so that the next copy will
|
|
* pick up from where this one left off.
|
|
*/
|
|
unsigned int usb_stor_access_xfer_buf(unsigned char *buffer,
|
|
unsigned int buflen, struct scsi_cmnd *srb, struct scatterlist **sgptr,
|
|
unsigned int *offset, enum xfer_buf_dir dir)
|
|
{
|
|
unsigned int cnt;
|
|
struct scatterlist *sg = *sgptr;
|
|
|
|
/* We have to go through the list one entry
|
|
* at a time. Each s-g entry contains some number of pages, and
|
|
* each page has to be kmap()'ed separately. If the page is already
|
|
* in kernel-addressable memory then kmap() will return its address.
|
|
* If the page is not directly accessible -- such as a user buffer
|
|
* located in high memory -- then kmap() will map it to a temporary
|
|
* position in the kernel's virtual address space.
|
|
*/
|
|
|
|
if (!sg)
|
|
sg = scsi_sglist(srb);
|
|
|
|
/* This loop handles a single s-g list entry, which may
|
|
* include multiple pages. Find the initial page structure
|
|
* and the starting offset within the page, and update
|
|
* the *offset and **sgptr values for the next loop.
|
|
*/
|
|
cnt = 0;
|
|
while (cnt < buflen && sg) {
|
|
struct page *page = sg_page(sg) +
|
|
((sg->offset + *offset) >> PAGE_SHIFT);
|
|
unsigned int poff = (sg->offset + *offset) & (PAGE_SIZE-1);
|
|
unsigned int sglen = sg->length - *offset;
|
|
|
|
if (sglen > buflen - cnt) {
|
|
|
|
/* Transfer ends within this s-g entry */
|
|
sglen = buflen - cnt;
|
|
*offset += sglen;
|
|
} else {
|
|
|
|
/* Transfer continues to next s-g entry */
|
|
*offset = 0;
|
|
sg = sg_next(sg);
|
|
}
|
|
|
|
/* Transfer the data for all the pages in this
|
|
* s-g entry. For each page: call kmap(), do the
|
|
* transfer, and call kunmap() immediately after. */
|
|
while (sglen > 0) {
|
|
unsigned int plen = min(sglen, (unsigned int)
|
|
PAGE_SIZE - poff);
|
|
unsigned char *ptr = kmap(page);
|
|
|
|
if (dir == TO_XFER_BUF)
|
|
memcpy(ptr + poff, buffer + cnt, plen);
|
|
else
|
|
memcpy(buffer + cnt, ptr + poff, plen);
|
|
kunmap(page);
|
|
|
|
/* Start at the beginning of the next page */
|
|
poff = 0;
|
|
++page;
|
|
cnt += plen;
|
|
sglen -= plen;
|
|
}
|
|
}
|
|
*sgptr = sg;
|
|
|
|
/* Return the amount actually transferred */
|
|
return cnt;
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_stor_access_xfer_buf);
|
|
|
|
/* Store the contents of buffer into srb's transfer buffer and set the
|
|
* SCSI residue.
|
|
*/
|
|
void usb_stor_set_xfer_buf(unsigned char *buffer,
|
|
unsigned int buflen, struct scsi_cmnd *srb)
|
|
{
|
|
unsigned int offset = 0;
|
|
struct scatterlist *sg = NULL;
|
|
|
|
buflen = min(buflen, scsi_bufflen(srb));
|
|
buflen = usb_stor_access_xfer_buf(buffer, buflen, srb, &sg, &offset,
|
|
TO_XFER_BUF);
|
|
if (buflen < scsi_bufflen(srb))
|
|
scsi_set_resid(srb, scsi_bufflen(srb) - buflen);
|
|
}
|
|
EXPORT_SYMBOL_GPL(usb_stor_set_xfer_buf);
|