openwrt/target/linux/generic/pending-5.4/770-09-net-ethernet-mtk_eth_soc-only-read-the-full-rx-descr.patch
Hauke Mehrtens b55d3d6904 kernel: bump 5.4 to 5.4.124
Manually rebased
  generic/hack-5.4/662-remove_pfifo_fast.patch
  ramips/patches-5.4/0048-asoc-add-mt7620-support.patch

All others updated automatically.

Compile-tested on: armvirt/64, x86/generic, ath79/generic, ramips/mt7621
Runtime-tested on: armvirt/64, x86/generic, ath79/generic

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
2021-06-06 17:54:51 +02:00

45 lines
1.3 KiB
Diff

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
@@ -793,13 +793,18 @@ 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 */
@@ -1271,8 +1276,7 @@ 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 */