From: Andrew Vasquez <andrewv@xxxxxxxxxxx> - Correct memory barriers to make sure all cmnds are flushed. Signed-off-by: Andrew Vasquez <andrewv@xxxxxxxxxxx> Signed-off-by: Saurav Kashyap <skashyap@xxxxxxxxxxx> --- drivers/scsi/qedf/qedf_io.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c index 1a36ab5..f04191f 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, -- 1.8.3.1
