SCSI & usb-storage: add flags for VPD pages and REPORT LUNS
This patch (as1507) adds a skip_vpd_pages flag to struct scsi_device
and a no_report_luns flag to struct scsi_target. The first is used to
control whether sd will look at VPD pages for information on block
provisioning, limits, and characteristics. The second prevents
scsi_report_lun_scan() from issuing a REPORT LUNS command.
The patch also modifies usb-storage to set the new flag bits for all
USB devices and targets, and to stop adjusting the scsi_level value.
Historically we have seen that USB mass-storage devices often don't
support VPD pages or REPORT LUNS properly. Until now we have avoided
these things by setting the scsi_level to SCSI_2 for all USB devices.
But this has the side effect of storing the LUN bits into the second
byte of each CDB, and now we have a report of a device which doesn't
like that. The best solution is to stop abusing scsi_level and
instead have separate flags for VPD pages and REPORT LUNS.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Perry Wagle <wagle@mac.com>
CC: Matthew Dharm <mdharm-usb@one-eyed-alien.net>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/storage/scsiglue.c b/drivers/usb/storage/scsiglue.c
index 13b8bcd..dc68cc9 100644
--- a/drivers/usb/storage/scsiglue.c
+++ b/drivers/usb/storage/scsiglue.c
@@ -197,6 +197,9 @@
* page x08, so we will skip it. */
sdev->skip_ms_page_8 = 1;
+ /* Some devices don't handle VPD pages correctly */
+ sdev->skip_vpd_pages = 1;
+
/* Some disks return the total number of blocks in response
* to READ CAPACITY rather than the highest block number.
* If this device makes that mistake, tell the sd driver. */
@@ -217,16 +220,6 @@
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
- * 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. */
- if (sdev->scsi_level > SCSI_2)
- sdev->sdev_target->scsi_level =
- sdev->scsi_level = SCSI_2;
-
/* USB-IDE bridges tend to report SK = 0x04 (Non-recoverable
* Hardware Error) when any low-level error occurs,
* recoverable or not. Setting this flag tells the SCSI
@@ -283,6 +276,18 @@
return 0;
}
+static int target_alloc(struct scsi_target *starget)
+{
+ /*
+ * Some USB drives don't support REPORT LUNS, even though they
+ * report a SCSI revision level above 2. Tell the SCSI layer
+ * not to issue that command; it will perform a normal sequential
+ * scan instead.
+ */
+ starget->no_report_luns = 1;
+ return 0;
+}
+
/* queue a command */
/* This is always called with scsi_lock(host) held */
static int queuecommand_lck(struct scsi_cmnd *srb,
@@ -546,6 +551,7 @@
.slave_alloc = slave_alloc,
.slave_configure = slave_configure,
+ .target_alloc = target_alloc,
/* lots of sg segments can be handled */
.sg_tablesize = SCSI_MAX_SG_CHAIN_SEGMENTS,