[PATCH] net: dm9000: Correctly handle empty FIFO

[Ramon Fried]

On Mon, Apr 25, 2022 at 9:28 PM Marek Vasut <marex at denx.de> wrote:
>
> Assign packet pointer only in case the MAC reports anything in the FIFO.
> In case the MAC indicates empty FIFO, return 0 to pass that information
> to the network stack.
>
> Signed-off-by: Marek Vasut <marex at denx.de>
> Cc: Joe Hershberger <joe.hershberger at ni.com>
> Cc: Ramon Fried <rfried.dev at gmail.com>
> ---
>  drivers/net/dm9000x.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/dm9000x.c b/drivers/net/dm9000x.c
> index 78ce536d4a3..07733df533e 100644
> --- a/drivers/net/dm9000x.c
> +++ b/drivers/net/dm9000x.c
> @@ -666,10 +666,10 @@ static int dm9000_recv(struct udevice *dev, int flags, uchar **packetp)
>         int ret;
>
>         ret = dm9000_recv_common(db, data);
> -       if (ret)
> +       if (ret > 0)
>                 *packetp = (void *)data;
>
> -       return ret ? ret : -EAGAIN;
> +       return ret >= 0 ? ret : -EAGAIN;
>  }
>
>  static int dm9000_write_hwaddr(struct udevice *dev)
> --
> 2.35.1
>
Reviewed-by: Ramon Fried <rfried.dev at gmail.com>