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[4/5] net: ethernet: mediatek: enable rx path by reducing memory barrier

Message ID 1471273430-19942-4-git-send-email-sean.wang@mediatek.com (mailing list archive)
State New, archived
Headers show

Commit Message

Sean Wang Aug. 15, 2016, 3:03 p.m. UTC
The patch makes moving wmb() to outside the loop that could help
rx path handling more faster although that rx descriptors aren't
freed for DMA to use as soon as possible, but based on my experiment
and the result show it still can reach about 943Mbpis tested on the
setup with one port using gigaphy and 256 rx descriptors for
DMA to move.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Comments

Sergei Shtylyov Aug. 15, 2016, 7:06 p.m. UTC | #1
Hello.

On 08/15/2016 06:03 PM, Sean Wang wrote:

> The patch makes moving wmb() to outside the loop that could help
> rx path handling more faster although that rx descriptors aren't

    RX.

> freed for DMA to use as soon as possible, but based on my experiment
> and the result show it still can reach about 943Mbpis tested on the

    Shows.

> setup with one port using gigaphy and 256 rx descriptors for

    RX.

> DMA to move.
>
> Signed-off-by: Sean Wang <sean.wang@mediatek.com>
> ---
>  drivers/net/ethernet/mediatek/mtk_eth_soc.c |   11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> index b782330..53e24c1 100644
> --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
> @@ -893,14 +893,15 @@ release_desc:
>  		rxd->rxd2 = RX_DMA_PLEN0(ring->buf_size);
>
>  		ring->calc_idx = idx;
> -		/* make sure that all changes to the dma ring are flushed before
> -		 * we continue
> -		 */
> -		wmb();
> -		mtk_w32(eth, ring->calc_idx, MTK_QRX_CRX_IDX0);
>  		done++;
>  	}
>
> +    /* make sure that all changes to the dma ring are flushed before
> +     * we continue
> +     */

    Please indent the comment with a tab, like the code after it.

> +	wmb();
> +	mtk_w32(eth, ring->calc_idx, MTK_QRX_CRX_IDX0);
> +
>  	if (done < budget)
>  		mtk_w32(eth, MTK_RX_DONE_INT, MTK_QMTK_INT_STATUS);
>

MBR, Sergei
diff mbox

Patch

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index b782330..53e24c1 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -893,14 +893,15 @@  release_desc:
 		rxd->rxd2 = RX_DMA_PLEN0(ring->buf_size);
 
 		ring->calc_idx = idx;
-		/* make sure that all changes to the dma ring are flushed before
-		 * we continue
-		 */
-		wmb();
-		mtk_w32(eth, ring->calc_idx, MTK_QRX_CRX_IDX0);
 		done++;
 	}
 
+    /* make sure that all changes to the dma ring are flushed before
+     * we continue
+     */
+	wmb();
+	mtk_w32(eth, ring->calc_idx, MTK_QRX_CRX_IDX0);
+
 	if (done < budget)
 		mtk_w32(eth, MTK_RX_DONE_INT, MTK_QMTK_INT_STATUS);