From b80ccf02c4a63a4b5db48b49abaccd2f58567561 Mon Sep 17 00:00:00 2001 From: James Smart Date: Mon, 19 Dec 2016 15:07:30 -0800 Subject: [PATCH] scsi: lpfc: Add missing memory barrier Orabug: 25486030 On loosely ordered memory systems (PPC for example), the WQE elements were being updated in memory, but not necessarily flushed before the separate doorbell was written to hw which would cause hw to dma the WQE element. Thus, the hardware occasionally received partially updated WQE data. Add the memory barrier after updating the WQE memory. Signed-off-by: Dick Kennedy Signed-off-by: James Smart Reviewed-by: Hannes Reinecke Signed-off-by: Martin K. Petersen (cherry picked from commit 6b3b3bdb83b4ad51252d21bb13596db879e51850) Signed-off-by: Brian Maly --- 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 eb6ba904b1ab..f743bc4cdef5 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -119,6 +119,8 @@ lpfc_sli4_wq_put(struct lpfc_queue *q, union lpfc_wqe *wqe) 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); + /* ensure WQE bcopy flushed before doorbell write */ + wmb(); /* Update the host index before invoking device */ host_index = q->host_index; -- 2.50.1