[PATCH 4.1 107/159] IB/mlx4: Fix incorrect cq flushing in error state

From: Greg Kroah-Hartman
Date: Sat Sep 26 2015 - 17:27:42 EST

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


From: Ariel Nahum <arieln@xxxxxxxxxxxx>

commit 799cdaf8a98f13d4fba3162e21e1e63f21045010 upstream.

When handling a device internal error, the driver is responsible to
drain the completion queue with flush errors.

In case a completion queue was assigned to multiple send queues, the
driver iterates over the send queues and generates flush errors of
inflight wqes. The driver must correctly pass the wc array with an
offset as a result of the previous send queue iteration. Not doing so
will overwrite previously set completions and return a wrong number
of polled completions which includes ones which were not correctly set.

Fixes: 35f05dabf95a (IB/mlx4: Reset flow support for IB kernel ULPs)
Signed-off-by: Ariel Nahum <arieln@xxxxxxxxxxxx>
Signed-off-by: Sagi Grimberg <sagig@xxxxxxxxxxxx>
Cc: Yishai Hadas <yishaih@xxxxxxxxxxxx>
Signed-off-by: Doug Ledford <dledford@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

drivers/infiniband/hw/mlx4/cq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/infiniband/hw/mlx4/cq.c
+++ b/drivers/infiniband/hw/mlx4/cq.c
@@ -629,7 +629,7 @@ static void mlx4_ib_poll_sw_comp(struct
* simulated FLUSH_ERR completions
list_for_each_entry(qp, &cq->send_qp_list, cq_send_list) {
- mlx4_ib_qp_sw_comp(qp, num_entries, wc, npolled, 1);
+ mlx4_ib_qp_sw_comp(qp, num_entries, wc + *npolled, npolled, 1);
if (*npolled >= num_entries)
goto out;

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