Re: [PATCH 4/4] bgmac: fix DMA rx corruption

[Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>]

Hello.

On 4/12/2015 1:08 PM, Felix Fietkau wrote:

> The driver needs to inform the hardware about the first invalid (not yet
> filled) rx slot, by writing its DMA descriptor pointer offset to the
> BGMAC_DMA_RX_INDEX register.

> This register was set to a value exceeding the rx ring size, effectively
> allowing the hardware constant access to the full ring, regardless of
> which slots are initialized.

> Fix this by updating the register in bgmac_dma_rx_setup_desc.

> Signed-off-by: Felix Fietkau <nbd@openwrt.org>
> ---
>   drivers/net/ethernet/broadcom/bgmac.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)

> diff --git a/drivers/net/ethernet/broadcom/bgmac.c b/drivers/net/ethernet/broadcom/bgmac.c
> index e332de8..856ceee 100644
> --- a/drivers/net/ethernet/broadcom/bgmac.c
> +++ b/drivers/net/ethernet/broadcom/bgmac.c
> @@ -380,6 +380,12 @@ static void bgmac_dma_rx_setup_desc(struct bgmac *bgmac,
>   	dma_desc->addr_high = cpu_to_le32(upper_32_bits(ring->slots[desc_idx].dma_addr));
>   	dma_desc->ctl0 = cpu_to_le32(ctl0);
>   	dma_desc->ctl1 = cpu_to_le32(ctl1);
> +
> +	desc_idx = (desc_idx + 1) % BGMAC_RX_RING_SLOTS;
> +
> +	bgmac_write(bgmac, ring->mmio_base + BGMAC_DMA_RX_INDEX,
> +			ring->index_base +
> +			desc_idx * sizeof(struct bgmac_dma_desc));

    The continuation lines should start on the next column after ( on the 
first line.

[...]

WBR, Sergei