USB: storage devices and SAT

Add the SANE SENSE flag to indicate that a device is capable of handling
more than 18-bytes of sense data.  This functionality is required for
USB-ATA bridges implementing SAT.  A future patch will actually enable this
function for several devices.

The logic behind this is that we can detect support for SANE_SENSE in a few ways:
 1) ATA PASS THROUGH (12) or (16) execute successfully
 2) SPC-3 or higher is in use
 3) A previous CHECK CONDITION occurred with sense format 70-73 and had
    a length greater than 18-bytes total

Signed-off-by: Ben Efros <ben@pc-doctor.com>
Signed-off-by: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Ben Efros 2008-11-18 13:31:13 -08:00 committed by Greg Kroah-Hartman
parent a658367dae
commit 1537e0ad94
3 changed files with 46 additions and 3 deletions

View file

@ -170,6 +170,10 @@ static int slave_configure(struct scsi_device *sdev)
if (us->fflags & US_FL_CAPACITY_HEURISTICS)
sdev->guess_capacity = 1;
/* assume SPC3 or latter devices support sense size > 18 */
if (sdev->scsi_level > SCSI_SPC_2)
us->fflags |= US_FL_SANE_SENSE;
/* Some devices report a SCSI revision level above 2 but are
* unable to handle the REPORT LUNS command (for which
* support is mandatory at level 3). Since we already have

View file

@ -578,6 +578,20 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
need_auto_sense = 1;
}
/*
* Determine if this device is SAT by seeing if the
* command executed successfully. Otherwise we'll have
* to wait for at least one CHECK_CONDITION to determine
* SANE_SENSE support
*/
if ((srb->cmnd[0] == ATA_16 || srb->cmnd[0] == ATA_12) &&
result == USB_STOR_TRANSPORT_GOOD &&
!(us->fflags & US_FL_SANE_SENSE) &&
!(srb->cmnd[2] & 0x20)) {
US_DEBUGP("-- SAT supported, increasing auto-sense\n");
us->fflags |= US_FL_SANE_SENSE;
}
/*
* A short transfer on a command where we don't expect it
* is unusual, but it doesn't mean we need to auto-sense.
@ -595,10 +609,15 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
if (need_auto_sense) {
int temp_result;
struct scsi_eh_save ses;
int sense_size = US_SENSE_SIZE;
/* device supports and needs bigger sense buffer */
if (us->fflags & US_FL_SANE_SENSE)
sense_size = ~0;
US_DEBUGP("Issuing auto-REQUEST_SENSE\n");
scsi_eh_prep_cmnd(srb, &ses, NULL, 0, US_SENSE_SIZE);
scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sense_size);
/* FIXME: we must do the protocol translation here */
if (us->subclass == US_SC_RBC || us->subclass == US_SC_SCSI ||
@ -632,6 +651,25 @@ void usb_stor_invoke_transport(struct scsi_cmnd *srb, struct us_data *us)
return;
}
/* If the sense data returned is larger than 18-bytes then we
* assume this device supports requesting more in the future.
* The response code must be 70h through 73h inclusive.
*/
if (srb->sense_buffer[7] > (US_SENSE_SIZE - 8) &&
!(us->fflags & US_FL_SANE_SENSE) &&
(srb->sense_buffer[0] & 0x7C) == 0x70) {
US_DEBUGP("-- SANE_SENSE support enabled\n");
us->fflags |= US_FL_SANE_SENSE;
/* Indicate to the user that we truncated their sense
* because we didn't know it supported larger sense.
*/
US_DEBUGP("-- Sense data truncated to %i from %i\n",
US_SENSE_SIZE,
srb->sense_buffer[7] + 8);
srb->sense_buffer[7] = (US_SENSE_SIZE - 8);
}
US_DEBUGP("-- Result from auto-sense is %d\n", temp_result);
US_DEBUGP("-- code: 0x%x, key: 0x%x, ASC: 0x%x, ASCQ: 0x%x\n",
srb->sense_buffer[0],

View file

@ -52,8 +52,9 @@
US_FLAG(MAX_SECTORS_MIN,0x00002000) \
/* Sets max_sectors to arch min */ \
US_FLAG(BULK_IGNORE_TAG,0x00004000) \
/* Ignore tag mismatch in bulk operations */
/* Ignore tag mismatch in bulk operations */ \
US_FLAG(SANE_SENSE, 0x00008000)
/* Sane Sense (> 18 bytes) */
#define US_FLAG(name, value) US_FL_##name = value ,
enum { US_DO_ALL_FLAGS };