From 895cf5f3d6cb72825919a39ae48a41476a821e65 Mon Sep 17 00:00:00 2001 From: Steve Wise Date: Thu, 20 May 2010 16:57:38 -0500 Subject: [PATCH] RDMA/cxgb4: CQ size must be IQ size - 2 We need 1 extra entry for the status page and 1 to always have 1 free entry to detect when the queue is full. Signed-off-by: Steve Wise Signed-off-by: Roland Dreier --- drivers/infiniband/hw/cxgb4/cq.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/cxgb4/cq.c b/drivers/infiniband/hw/cxgb4/cq.c index fb1aafcc294f..46ac00f728f3 100644 --- a/drivers/infiniband/hw/cxgb4/cq.c +++ b/drivers/infiniband/hw/cxgb4/cq.c @@ -780,6 +780,9 @@ struct ib_cq *c4iw_create_cq(struct ib_device *ibdev, int entries, /* account for the status page. */ entries++; + /* IQ needs one extra entry to differentiate full vs empty. */ + entries++; + /* * entries must be multiple of 16 for HW. */ @@ -801,7 +804,7 @@ struct ib_cq *c4iw_create_cq(struct ib_device *ibdev, int entries, chp->rhp = rhp; chp->cq.size--; /* status page */ - chp->ibcq.cqe = chp->cq.size; + chp->ibcq.cqe = chp->cq.size - 1; spin_lock_init(&chp->lock); atomic_set(&chp->refcnt, 1); init_waitqueue_head(&chp->wait); -- 2.39.5