[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>
This commit is contained in:
Hans de Goede 2008-01-20 11:12:26 +01:00 committed by James Bottomley
parent b523381e32
commit a0899d4df5
2 changed files with 10 additions and 0 deletions

View file

@ -395,6 +395,15 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
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));

View file

@ -139,6 +139,7 @@ struct scsi_device {
unsigned fix_capacity:1; /* READ_CAPACITY is too high by 1 */
unsigned guess_capacity:1; /* READ_CAPACITY might be too high by 1 */
unsigned retry_hwerror:1; /* Retry HARDWARE_ERROR */
unsigned last_sector_bug:1; /* Always read last sector in a 1 sector read */
DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
struct list_head event_list; /* asserted events */