ramips: add mt7621 ethernet driver improvements

- Speed up MDIO bus access
- Improve performance on tx completion

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/target/linux/ramips/patches-5.4/0400-net-ethernet-mediatek-use-napi_consume_skb.patch b/target/linux/ramips/patches-5.4/0400-net-ethernet-mediatek-use-napi_consume_skb.patch
new file mode 100644 (file)
index 0000000..1ccb85d
--- /dev/null
+++ b/target/linux/ramips/patches-5.4/0400-net-ethernet-mediatek-use-napi_consume_skb.patch
@@ -0,0 +1,72 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Mon, 8 Jun 2020 17:01:12 +0200
+Subject: [PATCH] net: ethernet: mediatek: use napi_consume_skb
+
+Should improve performance, since it can use bulk free
+
+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
+@@ -844,7 +844,8 @@ static int txd_to_idx(struct mtk_tx_ring
+       return ((void *)dma - (void *)ring->dma) / sizeof(*dma);
+ }
+ 
+-static void mtk_tx_unmap(struct mtk_eth *eth, struct mtk_tx_buf *tx_buf)
++static void mtk_tx_unmap(struct mtk_eth *eth, struct mtk_tx_buf *tx_buf,
++                       bool napi)
+ {
+       if (MTK_HAS_CAPS(eth->soc->caps, MTK_QDMA)) {
+               if (tx_buf->flags & MTK_TX_FLAGS_SINGLE0) {
+@@ -876,8 +877,12 @@ static void mtk_tx_unmap(struct mtk_eth
+ 
+       tx_buf->flags = 0;
+       if (tx_buf->skb &&
+-          (tx_buf->skb != (struct sk_buff *)MTK_DMA_DUMMY_DESC))
+-              dev_kfree_skb_any(tx_buf->skb);
++          (tx_buf->skb != (struct sk_buff *)MTK_DMA_DUMMY_DESC)) {
++              if (napi)
++                      napi_consume_skb(tx_buf->skb, napi);
++              else
++                      dev_kfree_skb_any(tx_buf->skb);
++      }
+       tx_buf->skb = NULL;
+ }
+ 
+@@ -1055,7 +1060,7 @@ err_dma:
+               tx_buf = mtk_desc_to_tx_buf(ring, itxd);
+ 
+               /* unmap dma */
+-              mtk_tx_unmap(eth, tx_buf);
++              mtk_tx_unmap(eth, tx_buf, false);
+ 
+               itxd->txd3 = TX_DMA_LS0 | TX_DMA_OWNER_CPU;
+               if (!MTK_HAS_CAPS(eth->soc->caps, MTK_QDMA))
+@@ -1373,7 +1378,7 @@ static int mtk_poll_tx_qdma(struct mtk_e
+                       done[mac]++;
+                       budget--;
+               }
+-              mtk_tx_unmap(eth, tx_buf);
++              mtk_tx_unmap(eth, tx_buf, true);
+ 
+               ring->last_free = desc;
+               atomic_inc(&ring->free_count);
+@@ -1410,7 +1415,7 @@ static int mtk_poll_tx_pdma(struct mtk_e
+                       budget--;
+               }
+ 
+-              mtk_tx_unmap(eth, tx_buf);
++              mtk_tx_unmap(eth, tx_buf, true);
+ 
+               desc = &ring->dma[cpu];
+               ring->last_free = desc;
+@@ -1612,7 +1617,7 @@ static void mtk_tx_clean(struct mtk_eth
+ 
+       if (ring->buf) {
+               for (i = 0; i < MTK_DMA_SIZE; i++)
+-                      mtk_tx_unmap(eth, &ring->buf[i]);
++                      mtk_tx_unmap(eth, &ring->buf[i], false);
+               kfree(ring->buf);
+               ring->buf = NULL;
+       }

diff --git a/target/linux/ramips/patches-5.4/0401-net-ethernet-mediatek-significantly-reduce-mdio-bus-.patch b/target/linux/ramips/patches-5.4/0401-net-ethernet-mediatek-significantly-reduce-mdio-bus-.patch
new file mode 100644 (file)
index 0000000..c2ba996
--- /dev/null
+++ b/target/linux/ramips/patches-5.4/0401-net-ethernet-mediatek-significantly-reduce-mdio-bus-.patch
@@ -0,0 +1,26 @@
+From: Felix Fietkau <nbd@nbd.name>
+Date: Mon, 8 Jun 2020 17:02:39 +0200
+Subject: [PATCH] net: ethernet: mediatek: significantly reduce mdio bus
+ access latency
+
+usleep_range often ends up sleeping much longer than the 10-20us provided
+as a range here. This causes significant latency in mdio bus acceses,
+which easily adds multiple seconds to the boot time on MT7621 when polling
+DSA slave ports.
+Use cond_resched instead of usleep_range, since the MDIO access does not
+take much time
+
+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
+@@ -85,7 +85,7 @@ static int mtk_mdio_busy_wait(struct mtk
+                       return 0;
+               if (time_after(jiffies, t_start + PHY_IAC_TIMEOUT))
+                       break;
+-              usleep_range(10, 20);
++              cond_resched();
+       }
+ 
+       dev_err(eth->dev, "mdio: MDIO timeout\n");