From 6b3b3bdb83b4ad51252d21bb13596db879e51850 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 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 --- 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 7e11cbdb238c..3a8470d55af5 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -120,6 +120,8 @@ 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;