On Mon, Dec 14, 2020 at 10:56 AM Lance Richardson
<lance.richard...@broadcom.com> wrote:
>
> Write completion queue doorbell before receive descriptor
> doorbell to avoid possibility of completion queue overflow
> when completion queue size is equal to receive descriptor
> ring size. Remove unnecessary compiler barriers (db write
> functions have the necessary barriers.)
>
> Fixes: 637e34befd9c ("net/bnxt: optimize Rx processing")
> Signed-off-by: Lance Richardson <lance.richard...@broadcom.com>
> Reviewed-by: Ajit Kumar Khaparde <ajit.khapa...@broadcom.com>
> Reviewed-by: Somnath Kotur <somnath.ko...@broadcom.com>
> Cc: sta...@dpdk.org
Patch applied to dpdk-next-net-brcm.
> ---
> v2 - Fixed typo in commit log.
>
> drivers/net/bnxt/bnxt_rxr.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/bnxt/bnxt_rxr.c b/drivers/net/bnxt/bnxt_rxr.c
> index e2d388e69f..ffdeeecc3a 100644
> --- a/drivers/net/bnxt/bnxt_rxr.c
> +++ b/drivers/net/bnxt/bnxt_rxr.c
> @@ -917,17 +917,17 @@ uint16_t bnxt_recv_pkts(void *rx_queue, struct rte_mbuf
> **rx_pkts,
> goto done;
> }
>
> - rte_compiler_barrier();
> + /* Ring the completion queue doorbell. */
> + bnxt_db_cq(cpr);
> +
> + /* Ring the receive descriptor doorbell. */
> if (rx_raw_prod != rxr->rx_raw_prod)
> bnxt_db_write(&rxr->rx_db, rxr->rx_raw_prod);
>
> - rte_compiler_barrier();
> /* Ring the AGG ring DB */
> if (ag_raw_prod != rxr->ag_raw_prod)
> bnxt_db_write(&rxr->ag_db, rxr->ag_raw_prod);
>
> - bnxt_db_cq(cpr);
> -
> /* Attempt to alloc Rx buf in case of a previous allocation failure.
> */
> if (rc == -ENOMEM) {
> int i = RING_NEXT(rx_raw_prod);
> --
> 2.25.1
>
>
> --
> This electronic communication and the information and any files transmitted
> with it, or attached to it, are confidential and are intended solely for
> the use of the individual or entity to whom it is addressed and may contain
> information that is confidential, legally privileged, protected by privacy
> laws, or otherwise restricted from disclosure to anyone else. If you are
> not the intended recipient or the person responsible for delivering the
> e-mail to the intended recipient, you are hereby notified that any use,
> copying, distributing, dissemination, forwarding, printing, or copying of
> this e-mail is strictly prohibited. If you received this e-mail in error,
> please return the e-mail to the sender, delete it from your computer, and
> destroy any printed copy of it.
--
Ajit Khaparde
