[SCSI] sd: add fix for devices with last sector access problems
This patch adds a new scsi_device flag (last_sector_bug) for devices
which contain a bug where the device crashes when the last sector is
read in a larger then 1 sector read.
This is for example the case with sdcards in the HP PSC1350 printer
cardreader and in the HP PSC1610 printer cardreader.
Signed-off-by: Hans de Goede <j.w.r.degoede@hhs.nl>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 212f6bc..24eba31 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -395,6 +395,15 @@
goto out;
}
+ /*
+ * Some devices (some sdcards for one) don't like it if the
+ * last sector gets read in a larger then 1 sector read.
+ */
+ if (unlikely(sdp->last_sector_bug &&
+ rq->nr_sectors > sdp->sector_size / 512 &&
+ block + this_count == get_capacity(disk)))
+ this_count -= sdp->sector_size / 512;
+
SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt, "block=%llu\n",
(unsigned long long)block));