[dpdk-dev] [PATCH 1/4] net/ena: fix incorrect Rx descriptors allocation

[Jakub Palider]

Looks good to me but please, check commnt on patch 2/4. Moving the "-1"
indexing fix from patch 2/4 into 1/4 will reflect all related changes in
one place. But this is not a functional change, so may go in current shape
as well.

Jakub

On Fri, Apr 7, 2017 at 12:48 PM, Marcin Wojtas <mw at semihalf.com> wrote:

> From: Michal Krawczyk <mk at semihalf.com>
>
> When application tried to allocate 1024 descriptors, device was not
> initializing properly.
>
> This patch solves it by avoiding allocation of all descriptors in the ring
> in one attempt. At least one descriptor must remain unused in the HW ring.
>
> Fixes: 1173fca25af9 ("ena: add polling-mode driver")
>
> Signed-off-by: Michal Krawczyk <mk at semihalf.com>
> ---
>  drivers/net/ena/ena_ethdev.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/ena/ena_ethdev.c b/drivers/net/ena/ena_ethdev.c
> index b5e6db6..2345bab 100644
> --- a/drivers/net/ena/ena_ethdev.c
> +++ b/drivers/net/ena/ena_ethdev.c
> @@ -919,7 +919,7 @@ static int ena_start(struct rte_eth_dev *dev)
>
>  static int ena_queue_restart(struct ena_ring *ring)
>  {
> -       int rc;
> +       int rc, bufs_num;
>
>         ena_assert_msg(ring->configured == 1,
>                        "Trying to restart unconfigured queue\n");
> @@ -930,8 +930,9 @@ static int ena_queue_restart(struct ena_ring *ring)
>         if (ring->type == ENA_RING_TYPE_TX)
>                 return 0;
>
> -       rc = ena_populate_rx_queue(ring, ring->ring_size);
> -       if ((unsigned int)rc != ring->ring_size) {
> +       bufs_num = ring->ring_size - 1;
> +       rc = ena_populate_rx_queue(ring, bufs_num);
> +       if (rc != bufs_num) {
>                 PMD_INIT_LOG(ERR, "Failed to populate rx ring !");
>                 return (-1);
>         }
> --
> 1.8.3.1
>
>