Re: [PATCH] r8169:Fill with zero Tx descriptors

[Ivan Vecera <ivecera@redhat.com>]

On 5.8.2015 12:46, Corcodel Marian wrote:
>   This patch fill with zero Tx descriptors before use.Is only
>   on    part by more patches but is critical.(critical)
>
>
> Signed-off-by: Corcodel Marian <corcodel.marian@gmail.com>
>
> diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c
> index 3df51fa..bf78f94 100644
> --- a/drivers/net/ethernet/realtek/r8169.c
> +++ b/drivers/net/ethernet/realtek/r8169.c
> @@ -7589,7 +7589,7 @@ static int rtl_open(struct net_device *dev)
>   	 * Rx and Tx descriptors needs 256 bytes alignment.
>   	 * dma_alloc_coherent provides more.
>   	 */
> -	tp->TxDescArray = dma_alloc_coherent(&pdev->dev, R8169_TX_RING_BYTES,
> +	tp->TxDescArray = dma_zalloc_coherent(&pdev->dev, R8169_TX_RING_BYTES,
>   					     &tp->TxPhyAddr, GFP_KERNEL);
>   	if (!tp->TxDescArray)
>   		goto err_pm_runtime_put;
>
Why? Why is zero-filling of tx-ring critical???

Ivan