libata: Clear tf before doing request sense (take 3)
patch 2/4:
Clear tf before doing request sense.
This fixes the AOpen 56X/AKH timeout problem.
(http://bugzilla.kernel.org/show_bug.cgi?id=8244)
Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index c89664a..39f556c 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -982,26 +982,27 @@
* RETURNS:
* 0 on success, AC_ERR_* mask on failure
*/
-static unsigned int atapi_eh_request_sense(struct ata_device *dev,
- unsigned char *sense_buf)
+static unsigned int atapi_eh_request_sense(struct ata_queued_cmd *qc)
{
+ struct ata_device *dev = qc->dev;
+ unsigned char *sense_buf = qc->scsicmd->sense_buffer;
struct ata_port *ap = dev->ap;
struct ata_taskfile tf;
u8 cdb[ATAPI_CDB_LEN];
DPRINTK("ATAPI request sense\n");
- ata_tf_init(dev, &tf);
-
/* FIXME: is this needed? */
memset(sense_buf, 0, SCSI_SENSE_BUFFERSIZE);
- /* XXX: why tf_read here? */
- ap->ops->tf_read(ap, &tf);
-
- /* fill these in, for the case where they are -not- overwritten */
+ /* initialize sense_buf with the error register,
+ * for the case where they are -not- overwritten
+ */
sense_buf[0] = 0x70;
- sense_buf[2] = tf.feature >> 4;
+ sense_buf[2] = qc->result_tf.feature >> 4;
+
+ /* some devices time out if garbage left in tf */
+ ata_tf_init(dev, &tf);
memset(cdb, 0, ATAPI_CDB_LEN);
cdb[0] = REQUEST_SENSE;
@@ -1165,8 +1166,7 @@
case ATA_DEV_ATAPI:
if (!(qc->ap->pflags & ATA_PFLAG_FROZEN)) {
- tmp = atapi_eh_request_sense(qc->dev,
- qc->scsicmd->sense_buffer);
+ tmp = atapi_eh_request_sense(qc);
if (!tmp) {
/* ATA_QCFLAG_SENSE_VALID is used to
* tell atapi_qc_complete() that sense