[patch 04/20] 2.6.xx: sata_mv: another critical fix

[Greg KH]

-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Mark Lord <lkml@xxxxxx>

This patch addresses a number of weird behaviours observed
for the sata_mv driver, by fixing an "off by one" bug in processing
of the EDMA response queue.

Basically, sata_mv was looking in the wrong place for
command results, and this produced a lot of unpredictable behaviour.

Signed-off-by: Mark Lord <mlord@xxxxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---

 drivers/scsi/sata_mv.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- linux-2.6.16.orig/drivers/scsi/sata_mv.c
+++ linux-2.6.16/drivers/scsi/sata_mv.c
@@ -1102,6 +1102,7 @@ static u8 mv_get_crpb_status(struct ata_
 	void __iomem *port_mmio = mv_ap_base(ap);
 	struct mv_port_priv *pp = ap->private_data;
 	u32 out_ptr;
+	u8 ata_status;
 
 	out_ptr = readl(port_mmio + EDMA_RSP_Q_OUT_PTR_OFS);
 
@@ -1109,6 +1110,8 @@ static u8 mv_get_crpb_status(struct ata_
 	assert(((out_ptr >> EDMA_RSP_Q_PTR_SHIFT) & MV_MAX_Q_DEPTH_MASK) ==
 	       pp->rsp_consumer);
 
+	ata_status = pp->crpb[pp->rsp_consumer].flags >> CRPB_FLAG_STATUS_SHIFT;
+
 	/* increment our consumer index... */
 	pp->rsp_consumer = mv_inc_q_index(&pp->rsp_consumer);
 
@@ -1123,7 +1126,7 @@ static u8 mv_get_crpb_status(struct ata_
 	writelfl(out_ptr, port_mmio + EDMA_RSP_Q_OUT_PTR_OFS);
 
 	/* Return ATA status register for completed CRPB */
-	return (pp->crpb[pp->rsp_consumer].flags >> CRPB_FLAG_STATUS_SHIFT);
+	return ata_status;
 }
 
 /**

--
-
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