[IB/mthca]: Fix error CQ entry handling on mem-free HCAs
Fix handling of error CQ entries on mem-free HCAs: the doorbell count
is never valid so we shouldn't look at it. This fixes problems exposed
by new HCA firmware.
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_cq.c b/drivers/infiniband/hw/mthca/mthca_cq.c
index b5aea7b..5687c30 100644
--- a/drivers/infiniband/hw/mthca/mthca_cq.c
+++ b/drivers/infiniband/hw/mthca/mthca_cq.c
@@ -373,8 +373,12 @@
* If we're at the end of the WQE chain, or we've used up our
* doorbell count, free the CQE. Otherwise just update it for
* the next poll operation.
+ *
+ * This does not apply to mem-free HCAs: they don't use the
+ * doorbell count field, and so we should always free the CQE.
*/
- if (!(new_wqe & cpu_to_be32(0x3f)) || (!cqe->db_cnt && dbd))
+ if (mthca_is_memfree(dev) ||
+ !(new_wqe & cpu_to_be32(0x3f)) || (!cqe->db_cnt && dbd))
return 0;
cqe->db_cnt = cpu_to_be16(be16_to_cpu(cqe->db_cnt) - dbd);