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>
diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index 2058db4..f584e72 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -579,6 +579,20 @@
}
/*
+ * 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 @@
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 @@
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],