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authorFelix Fietkau <nbd@nbd.name>2021-04-22 22:21:04 -0700
committerDavid S. Miller <davem@davemloft.net>2021-04-23 13:31:58 -0700
commit816ac3e6e67bdd78d86226c6eb53619780750e92 (patch)
tree3441f3df81b388b4c299cc7ed8dde468788f9983 /drivers/net/ethernet/mediatek
parent4e6bf609569c59b6bd6acf4a607c096cbd820d79 (diff)
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> Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/mediatek')
-rw-r--r--drivers/net/ethernet/mediatek/mtk_eth_soc.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 6d23118b7a6c..4735942ed283 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -777,13 +777,18 @@ static inline int mtk_max_buf_size(int frag_size)
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 */
@@ -1255,8 +1260,7 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
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 */