The first byte of each CRQ entry is used to indicate whether an entry is
a valid response or free for the VIOS to use. After processing a
response the driver sets the valid byte to zero to indicate the entry is
now free to be reused. Add a memory barrier after this write to ensure
no other stores are reordered when updating the valid byte.
Signed-off-by: Tyrel Datwyler <tyreld@xxxxxxxxxxxxxxxxxx>
---
drivers/scsi/ibmvscsi/ibmvscsi.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index d9534ee..2f5b07e 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -232,6 +232,7 @@ static void ibmvscsi_task(void *data)
while ((crq = crq_queue_next_crq(&hostdata->queue)) != NULL) {
ibmvscsi_handle_crq(crq, hostdata);
crq->valid = VIOSRP_CRQ_FREE;
+ wmb();
}
vio_enable_interrupts(vdev);
@@ -240,6 +241,7 @@ static void ibmvscsi_task(void *data)
vio_disable_interrupts(vdev);
ibmvscsi_handle_crq(crq, hostdata);
crq->valid = VIOSRP_CRQ_FREE;
+ wmb();
} else {
done = 1;
}
--
1.8.3.1
--
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
