From: Keith Busch <keith.busch@intel.com>
Date: Wed, 6 Jun 2018 08:13:05 -0600
Subject: [PATCH] nvme-pci: remove unnecessary completion doorbell check
Git-commit: 397c699fb096e7a822990990c17c6b43e829cfc4
Patch-mainline: v4.18-rc1
References: bsc#1104967,FATE#325924

The nvme pci driver never unmaps the doorbell registers while the requests
are active, so we can always safely update the completion queue head.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/nvme/host/pci.c | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index a7bed8dccd61..4963a407e728 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -920,11 +920,9 @@ static inline void nvme_ring_cq_doorbell(struct nvme_queue *nvmeq)
 {
 	u16 head = nvmeq->cq_head;
 
-	if (likely(nvmeq->cq_vector >= 0)) {
-		if (nvme_dbbuf_update_and_check_event(head, nvmeq->dbbuf_cq_db,
-						      nvmeq->dbbuf_cq_ei))
-			writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
-	}
+	if (nvme_dbbuf_update_and_check_event(head, nvmeq->dbbuf_cq_db,
+					      nvmeq->dbbuf_cq_ei))
+		writel(head, nvmeq->q_db + nvmeq->dev->db_stride);
 }
 
 static inline void nvme_handle_cqe(struct nvme_queue *nvmeq, u16 idx)
-- 
2.16.4