[PATCH] Force starget->scsi_level in usb-storage scsiglue.c

[Paul Walmsley <paul@booyaka.com>]

When the usb-storage module forces sdev->scsi_level to SCSI_2, it should 
also force starget->scsi_level to the same value.  Otherwise, the SCSI 
layer may attempt to issue SCSI-3 commands to the device, such as REPORT 
LUNS, which it cannot handle.  This can prevent the device from working 
with Linux.

The AMS Venus DS3 DS2316SU2S SATA-to-SATA+USB enclosure, based on the
Oxford Semiconductor OXU921S chip, requires this patch to function
correctly on Linux.  The enclosure reports a SCSI-3 SPC-2 command set
level, but does not correctly handle the REPORT LUNS SCSI command -
probably due to a bug in its firmware.

It seems likely that other USB storage enclosures with similar bugs
will also benefit from this patch.

Tony Lindgren <tony@atomide.com> collaborated in the development of this
patch.

Signed-off-by: Paul Walmsley <paul@booyaka.com>


- Paul

diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 4837524..4ef5527 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -109,7 +109,7 @@ static int slave_configure(struct scsi_d
 	 * data comes from.
 	 */
 	if (sdev->scsi_level < SCSI_2)
-		sdev->scsi_level = SCSI_2;
+		sdev->scsi_level = sdev->sdev_target->scsi_level = SCSI_2;

 	/* According to the technical support people at Genesys Logic,
 	 * devices using their chips have problems transferring more than
@@ -162,7 +162,7 @@ static int slave_configure(struct scsi_d
 		 * a Get-Max-LUN request, we won't lose much by setting the
 		 * revision level down to 2.  The only devices that would be
 		 * affected are those with sparse LUNs. */
-		sdev->scsi_level = SCSI_2;
+		sdev->scsi_level = sdev->sdev_target->scsi_level = SCSI_2;

 		/* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
 		 * Hardware Error) when any low-level error occurs,



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