[PATCH] net: sh_eth: Fix RX error handling

[Ramon Fried]

On Sun, Apr 30, 2023 at 5:54 PM Marek Vasut
<marek.vasut+renesas at mailbox.org> wrote:
>
> From: Valentine Barshak <valentine.barshak at cogentembedded.com>
>
> In case RX error occurs, and the RD_RFE bit is set, the descriptor
> is never returned back to the queue. Make sh_eth_recv_start return
> zero length in this case so that the descriptor can be released
> and pushed back to the list. Also return the more appropriate
> -EAGAIN instead of -EINVAL if the descriptor is not ready yet.
>
> Reviewed-by: Marek Vasut <marek.vasut+renesas at mailbox.org>
> Signed-off-by: Valentine Barshak <valentine.barshak at cogentembedded.com>
> ---
> Cc: Joe Hershberger <joe.hershberger at ni.com>
> Cc: Ramon Fried <rfried.dev at gmail.com>
> ---
>  drivers/net/sh_eth.c | 16 +++++++---------
>  1 file changed, 7 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/net/sh_eth.c b/drivers/net/sh_eth.c
> index 8f162ca58fb..da1bc7cb40b 100644
> --- a/drivers/net/sh_eth.c
> +++ b/drivers/net/sh_eth.c
> @@ -129,11 +129,11 @@ static int sh_eth_recv_start(struct sh_eth_dev *eth)
>         /* Check if the rx descriptor is ready */
>         invalidate_cache(port_info->rx_desc_cur, sizeof(struct rx_desc_s));
>         if (port_info->rx_desc_cur->rd0 & RD_RACT)
> -               return -EINVAL;
> +               return -EAGAIN;
>
>         /* Check for errors */
>         if (port_info->rx_desc_cur->rd0 & RD_RFE)
> -               return -EINVAL;
> +               return 0;
>
>         return port_info->rx_desc_cur->rd1 & 0xffff;
>  }
> @@ -555,15 +555,13 @@ static int sh_ether_recv(struct udevice *dev, int flags, uchar **packetp)
>                 *packetp = packet;
>
>                 return len;
> -       } else {
> -               len = 0;
> +       }
>
> -               /* Restart the receiver if disabled */
> -               if (!(sh_eth_read(port_info, EDRRR) & EDRRR_R))
> -                       sh_eth_write(port_info, EDRRR_R, EDRRR);
> +       /* Restart the receiver if disabled */
> +       if (!(sh_eth_read(port_info, EDRRR) & EDRRR_R))
> +               sh_eth_write(port_info, EDRRR_R, EDRRR);
>
> -               return -EAGAIN;
> -       }
> +       return len;
>  }
>
>  static int sh_ether_free_pkt(struct udevice *dev, uchar *packet, int length)
> --
> 2.39.2
>
Reviewed-by: Ramon Fried <rfried.dev at gmail.com>