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Commit 1537e0ad authored by Ben Efros's avatar Ben Efros Committed by Greg Kroah-Hartman
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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: default avatarBen Efros <ben@pc-doctor.com>
Signed-off-by: default avatarMatthew Dharm <mdharm-usb@one-eyed-alien.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent a658367d

drivers/usb/storage/scsiglue.c

+4 −0
Original line number Diff line number Diff line
@@ -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

drivers/usb/storage/transport.c

+39 −1
Original line number Diff line number Diff line
@@ -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],

include/linux/usb_usual.h

+3 −2
Original line number Diff line number Diff line
@@ -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 };