[SCSI] ibmvfc: Fix errors due to inconsistent command data

In order to ensure the VIOS sees a consistent command buffer, we
need to add a memory barrier after building the command buffer
but before sending the command.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index 2aa3d695d548..a401e938a87a 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -1381,6 +1381,8 @@ static int ibmvfc_send_event(struct ibmvfc_event *evt,
                 add_timer(&evt->timer);
         }
 
+        mb();
+
         if ((rc = ibmvfc_send_crq(vhost, crq_as_u64[0], crq_as_u64[1]))) {
                 list_del(&evt->queue);
                 del_timer(&evt->timer);