Merge remote-tracking branch 'scsi-queue/drivers-for-3.16' into for-linus

1 files changed, 12 insertions, 1 deletions

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index 2ebfb2bb0f42..7b23f21f22f1 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -185,6 +185,11 @@ static struct viosrp_crq *crq_queue_next_crq(struct crq_queue *queue)
 	if (crq->valid & 0x80) {
 		if (++queue->cur == queue->size)
 			queue->cur = 0;
+
+		/* Ensure the read of the valid bit occurs before reading any
+		 * other bits of the CRQ entry
+		 */
+		rmb();
 	} else
 		crq = NULL;
 	spin_unlock_irqrestore(&queue->lock, flags);
@@ -203,6 +208,11 @@ static int ibmvscsi_send_crq(struct ibmvscsi_host_data *hostdata,
 {
 	struct vio_dev *vdev = to_vio_dev(hostdata->dev);
 
+	/*
+	 * Ensure the command buffer is flushed to memory before handing it
+	 * over to the VIOS to prevent it from fetching any stale data.
+	 */
+	mb();
 	return plpar_hcall_norets(H_SEND_CRQ, vdev->unit_address, word1, word2);
 }
 
@@ -797,7 +807,8 @@ static void purge_requests(struct ibmvscsi_host_data *hostdata, int error_code)
 				       evt->hostdata->dev);
 			if (evt->cmnd_done)
 				evt->cmnd_done(evt->cmnd);
-		} else if (evt->done)
+		} else if (evt->done && evt->crq.format != VIOSRP_MAD_FORMAT &&
+			   evt->iu.srp.login_req.opcode != SRP_LOGIN_REQ)
 			evt->done(evt);
 		free_event_struct(&evt->hostdata->pool, evt);
 		spin_lock_irqsave(hostdata->host->host_lock, flags);