diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/scsi/qedf/qedf_io.c | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c index 58257ecfaf08..ab6705660e67 100644 --- a/drivers/scsi/qedf/qedf_io.c +++ b/drivers/scsi/qedf/qedf_io.c @@ -773,10 +773,18 @@ void qedf_ring_doorbell(struct qedf_rport *fcport) FCOE_DB_DATA_AGG_VAL_SEL_SHIFT; dbell.sq_prod = fcport->fw_sq_prod_idx; + /* wmb makes sure that the BDs data is updated before updating the + * producer, otherwise FW may read old data from the BDs. + */ + wmb(); + barrier(); writel(*(u32 *)&dbell, fcport->p_doorbell); - /* Make sure SQ index is updated so f/w prcesses requests in order */ + /* + * Fence required to flush the write combined buffer, since another + * CPU may write to the same doorbell address and data may be lost + * due to relaxed order nature of write combined bar. + */ wmb(); - mmiowb(); } static void qedf_trace_io(struct qedf_rport *fcport, struct qedf_ioreq *io_req, |