enic: Bug Fix: Handle surprise hardware removals

Handle surprise hardware removals gracefully during devcmd issue and init,
cleanup of queues.

Signed-off-by: Scott Feldman <scofeldm@cisco.com>
Signed-off-by: Vasanthy Kolluri <vkolluri@cisco.com>
Signed-off-by: Roopa Prabhu <roprabhu@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/net/enic/vnic_rq.c b/drivers/net/enic/vnic_rq.c
index 45cfc79f9f98..061a26fbbbfb 100644
--- a/drivers/net/enic/vnic_rq.c
+++ b/drivers/net/enic/vnic_rq.c
@@ -146,6 +146,11 @@ void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
         /* Use current fetch_index as the ring starting point */
         fetch_index = ioread32(&rq->ctrl->fetch_index);
 
+        if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
+                /* Hardware surprise removal: reset fetch_index */
+                fetch_index = 0;
+        }
+
         vnic_rq_init_start(rq, cq_index,
                 fetch_index, fetch_index,
                 error_interrupt_enable,
@@ -187,8 +192,6 @@ void vnic_rq_clean(struct vnic_rq *rq,
         u32 fetch_index;
         unsigned int count = rq->ring.desc_count;
 
-        BUG_ON(ioread32(&rq->ctrl->enable));
-
         buf = rq->to_clean;
 
         while (vnic_rq_desc_used(rq) > 0) {
@@ -201,6 +204,12 @@ void vnic_rq_clean(struct vnic_rq *rq,
 
         /* Use current fetch_index as the ring starting point */
         fetch_index = ioread32(&rq->ctrl->fetch_index);
+
+        if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
+                /* Hardware surprise removal: reset fetch_index */
+                fetch_index = 0;
+        }
+
         rq->to_use = rq->to_clean =
                 &rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
                         [fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];