diff options
Diffstat (limited to 'target/linux/generic/pending-5.4/770-09-net-ethernet-mtk_eth_soc-only-read-the-full-rx-descr.patch')
| -rw-r--r-- | target/linux/generic/pending-5.4/770-09-net-ethernet-mtk_eth_soc-only-read-the-full-rx-descr.patch | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/target/linux/generic/pending-5.4/770-09-net-ethernet-mtk_eth_soc-only-read-the-full-rx-descr.patch b/target/linux/generic/pending-5.4/770-09-net-ethernet-mtk_eth_soc-only-read-the-full-rx-descr.patch new file mode 100644 index 0000000000..1b7a0a9aca --- /dev/null +++ b/target/linux/generic/pending-5.4/770-09-net-ethernet-mtk_eth_soc-only-read-the-full-rx-descr.patch @@ -0,0 +1,44 @@ +From: Felix Fietkau <nbd@nbd.name> +Date: Thu, 27 Aug 2020 09:24:25 +0200 +Subject: [PATCH] net: ethernet: mtk_eth_soc: only read the full rx + descriptor if DMA is done + +Uncached memory access is expensive, and there is no need to access all +descriptor words if we can't process them anyway + +Signed-off-by: Felix Fietkau <nbd@nbd.name> +--- + +--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c ++++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c +@@ -772,13 +772,18 @@ static inline int mtk_max_buf_size(int f + return buf_size; + } + +-static inline void mtk_rx_get_desc(struct mtk_rx_dma *rxd, ++static inline bool mtk_rx_get_desc(struct mtk_rx_dma *rxd, + struct mtk_rx_dma *dma_rxd) + { +- rxd->rxd1 = READ_ONCE(dma_rxd->rxd1); + rxd->rxd2 = READ_ONCE(dma_rxd->rxd2); ++ if (!(rxd->rxd2 & RX_DMA_DONE)) ++ return false; ++ ++ rxd->rxd1 = READ_ONCE(dma_rxd->rxd1); + rxd->rxd3 = READ_ONCE(dma_rxd->rxd3); + rxd->rxd4 = READ_ONCE(dma_rxd->rxd4); ++ ++ return true; + } + + /* the qdma core needs scratch memory to be setup */ +@@ -1250,8 +1255,7 @@ static int mtk_poll_rx(struct napi_struc + rxd = &ring->dma[idx]; + data = ring->data[idx]; + +- mtk_rx_get_desc(&trxd, rxd); +- if (!(trxd.rxd2 & RX_DMA_DONE)) ++ if (!mtk_rx_get_desc(&trxd, rxd)) + break; + + /* find out which mac the packet come from. values start at 1 */ |