On Tue, 3 Jan 2012, Perry Wagle wrote:
> > You can test this by applying the patch below. If it fixes the
> > problem, we'll know the diagnosis is correct.
>
> With the patch, I'm able to mount both disks. Thanks!
>
> Now what?
Now that we know what the problem is, here's a real fix. Replace the
previous patch with this one; if it works okay then I'll submit it for
inclusion in the next stable kernel release.
Alan Stern
Index: usb-3.2/include/scsi/scsi_device.h
===================================================================
--- usb-3.2.orig/include/scsi/scsi_device.h
+++ usb-3.2/include/scsi/scsi_device.h
@@ -249,6 +249,8 @@ struct scsi_target {
* for the device at a time. */
unsigned int pdt_1f_for_no_lun; /* PDT = 0x1f */
/* means no lun present */
+ unsigned int no_report_luns:1; /* Don't use
+ * REPORT LUNS for scanning. */
/* commands actually active on LLD. protected by host lock. */
unsigned int target_busy;
/*
Index: usb-3.2/drivers/scsi/scsi_scan.c
===================================================================
--- usb-3.2.orig/drivers/scsi/scsi_scan.c
+++ usb-3.2/drivers/scsi/scsi_scan.c
@@ -1295,6 +1295,7 @@ EXPORT_SYMBOL(int_to_scsilun);
* LUNs even if it's older than SCSI-3.
* If BLIST_NOREPORTLUN is set, return 1 always.
* If BLIST_NOLUN is set, return 0 always.
+ * If starget->no_report_luns is set, return 1 always.
*
* Return:
* 0: scan completed (or no memory, so further scanning is futile)
@@ -1321,6 +1322,7 @@ static int scsi_report_lun_scan(struct s
* Only support SCSI-3 and up devices if BLIST_NOREPORTLUN is not set.
* Also allow SCSI-2 if BLIST_REPORTLUN2 is set and host adapter does
* support more than 8 LUNs.
+ * Don't attempt if the target doesn't support REPORT LUNS.
*/
if (bflags & BLIST_NOREPORTLUN)
return 1;
@@ -1332,6 +1334,8 @@ static int scsi_report_lun_scan(struct s
return 1;
if (bflags & BLIST_NOLUN)
return 0;
+ if (starget->no_report_luns)
+ return 1;
if (!(sdev = scsi_device_lookup_by_target(starget, 0))) {
sdev = scsi_alloc_sdev(starget, 0, NULL);
Index: usb-3.2/drivers/usb/storage/scsiglue.c
===================================================================
--- usb-3.2.orig/drivers/usb/storage/scsiglue.c
+++ usb-3.2/drivers/usb/storage/scsiglue.c
@@ -217,16 +217,6 @@ static int slave_configure(struct scsi_d
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 +273,18 @@ static int slave_configure(struct scsi_d
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 +548,7 @@ struct scsi_host_template usb_stor_host_
.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,
--
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