On 12/20/2016 12:07 AM, James Smart wrote: > > 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 <dick.kennedy@xxxxxxxxxxxx> > Signed-off-by: James Smart <james.smart@xxxxxxxxxxxx> > --- > v2: > revised for checkpatch warning - comment before wmb() > > 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 d0ffcf3..5c8663f 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; > Reviewed-by: Hannes Reinecke <hare@xxxxxxxx> Cheers, Hannes -- Dr. Hannes Reinecke Teamlead Storage & Networking hare@xxxxxxx +49 911 74053 688 SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton HRB 21284 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
