Re: [PATCH resend v2] net: cadence_gem: clear RX control descriptor

["Edgar E. Iglesias" <edgar.iglesias@gmail.com>]

On Sat, Apr 18, 2020 at 11:51:45AM +0300, Ramon Fried wrote:
> The RX ring descriptors control field is used for setting
> SOF and EOF (start of frame and end of frame).
> The SOF and EOF weren't cleared from the previous descriptors,
> causing inconsistencies in ring buffer.
> Fix that by clearing the control field of every descriptors we're
> processing.
> 
> Signed-off-by: Ramon Fried <rfried.dev@gmail.com>
> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Reviewed-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>


> 
> ---
> v2:
>   * change function name to rx_desc_clear_control as proposed by
>       Jason Wang
>   * Move the function call above the comment, as proposed by
>     Philippe Mathieu-Daudé
> 
>  hw/net/cadence_gem.c | 7 +++++++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
> index b7b7985bf2..22a0b1b1f9 100644
> --- a/hw/net/cadence_gem.c
> +++ b/hw/net/cadence_gem.c
> @@ -411,6 +411,11 @@ static inline void rx_desc_set_sof(uint32_t *desc)
>      desc[1] |= DESC_1_RX_SOF;
>  }
>  
> +static inline void rx_desc_clear_control(uint32_t *desc)
> +{
> +    desc[1]  = 0;
> +}
> +
>  static inline void rx_desc_set_eof(uint32_t *desc)
>  {
>      desc[1] |= DESC_1_RX_EOF;
> @@ -999,6 +1004,8 @@ static ssize_t gem_receive(NetClientState *nc, const uint8_t *buf, size_t size)
>          rxbuf_ptr += MIN(bytes_to_copy, rxbufsize);
>          bytes_to_copy -= MIN(bytes_to_copy, rxbufsize);
>  
> +        rx_desc_clear_control(s->rx_desc[q]);
> +
>          /* Update the descriptor.  */
>          if (first_desc) {
>              rx_desc_set_sof(s->rx_desc[q]);
> -- 
> 2.26.0
>