From 48e835f89769a1fcb1cf15259c734600891d87f5 Mon Sep 17 00:00:00 2001 From: James Smart Date: Tue, 30 Jan 2018 15:58:45 -0800 Subject: [PATCH] scsi: lpfc: Fix frequency of Release WQE CQEs [ Upstream commit 04673e38f56b30cd39b1fa0f386137d818b17781 ] The driver controls when the hardware sends completions that communicate consumption of elements from the WQ. This is done by setting a WQEC bit on a WQE. The current driver sets it on every Nth WQE posting. However, the driver isn't clearing the bit if the WQE is reused. Thus, if the queue depth isn't evenly divisible by N, with enough time, it can be set on every element, creating a lot of overhead and risking CQ full conditions. Correct by clearing the bit when not setting it on an Nth element. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/lpfc/lpfc_sli.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 455f3ce9fda9..dc83498024dc 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -129,6 +129,8 @@ lpfc_sli4_wq_put(struct lpfc_queue *q, union lpfc_wqe *wqe) /* set consumption flag every once in a while */ if (!((q->host_index + 1) % q->entry_repost)) bf_set(wqe_wqec, &wqe->generic.wqe_com, 1); + else + bf_set(wqe_wqec, &wqe->generic.wqe_com, 0); if (q->phba->sli3_options & LPFC_SLI4_PHWQ_ENABLED) bf_set(wqe_wqid, &wqe->generic.wqe_com, q->queue_id); lpfc_sli_pcimem_bcopy(wqe, temp_wqe, q->entry_size); -- 2.20.1