From 635372ada412967b359421e88c2c0acd35d4e3b5 Mon Sep 17 00:00:00 2001 From: Sean Wang Date: Sat, 3 Sep 2016 17:59:26 +0800 Subject: [PATCH] net: ethernet: mediatek: enhance RX path by reducing the frequency of the memory barrier used The patch makes move 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 shows it still can reach about 943Mbpis without performance drop that is tested based on the setup with one port using Giga PHY and 256 RX descriptors for DMA to move. Signed-off-by: Sean Wang Signed-off-by: David S. Miller --- 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 2dadfa961898..b43700587c88 100644 --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -895,13 +895,14 @@ 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_PRX_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_PRX_CRX_IDX0); if (done < budget) mtk_w32(eth, MTK_RX_DONE_INT, MTK_PDMA_INT_STATUS); -- 2.20.1