On Thu, Nov 26, 2015 at 07:08:11PM +0100, Marcin Wojtas wrote:
> In the actual RX processing, there is same error path for both descriptor
> ring refilling and building skb fails. This is not correct, because after
> successful refill, the ring is already updated with newly allocated
> buffer. Then, in case of build_skb() fail, hitherto code left the original
> buffer unmapped.
>
> This patch fixes above situation by swapping error check of skb build with
> DMA-unmap of original buffer.
>
> Signed-off-by: Marcin Wojtas <mw@xxxxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.2+
> Fixes a84e32894191 ("net: mvneta: fix refilling for Rx DMA buffers")
> ---
> drivers/net/ethernet/marvell/mvneta.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
Acked-by: Simon Guinot <simon.guinot@xxxxxxxxxxxx>
Thanks,
Simon
> diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
> index 0c3d923..62cf971 100644
> --- a/drivers/net/ethernet/marvell/mvneta.c
> +++ b/drivers/net/ethernet/marvell/mvneta.c
> @@ -1580,12 +1580,16 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
> }
>
> skb = build_skb(data, pp->frag_size > PAGE_SIZE ? 0 : pp->frag_size);
> - if (!skb)
> - goto err_drop_frame;
>
> + /* After refill old buffer has to be unmapped regardless
> + * the skb is successfully built or not.
> + */
> dma_unmap_single(dev->dev.parent, phys_addr,
> MVNETA_RX_BUF_SIZE(pp->pkt_size), DMA_FROM_DEVICE);
>
> + if (!skb)
> + goto err_drop_frame;
> +
> rcvd_pkts++;
> rcvd_bytes += rx_bytes;
>
> --
> 1.8.3.1
>
>
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