ramips: add jumbo frame support for v4.9

Signed-off-by: John Crispin <john@phrozen.org>

target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/gsw_mt7620.h

@@ -47,6 +47,12 @@
 #define GSW_REG_ISR		0x700c
 #define GSW_REG_GPC1		0x7014
 
+#define GSW_REG_MAC_P0_MCR	0x100
+#define GSW_REG_MAC_P1_MCR	0x200
+
+// Global MAC control register
+#define GSW_REG_GMACCR		0x30E0
+
 #define SYSC_REG_CHIP_REV_ID	0x0c
 #define SYSC_REG_CFG1		0x14
 #define RST_CTRL_MCM		BIT(2)

target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/gsw_mt7621.c

@@ -100,16 +100,19 @@ static void mt7621_hw_init(struct mt7620_gsw *gsw, struct device_node *np)
 
 	if ((rt_sysc_r32(SYSC_REG_CHIP_REV_ID) & 0xFFFF) == 0x0101) {
 		/* (GE1, Force 1000M/FD, FC ON, MAX_RX_LENGTH 1536) */
-		mtk_switch_w32(gsw, 0x2105e30b, 0x100);
+		mtk_switch_w32(gsw, 0x2305e30b, GSW_REG_MAC_P0_MCR);
 		mt7530_mdio_w32(gsw, 0x3600, 0x5e30b);
 	} else {
 		/* (GE1, Force 1000M/FD, FC ON, MAX_RX_LENGTH 1536) */
-		mtk_switch_w32(gsw, 0x2105e33b, 0x100);
+		mtk_switch_w32(gsw, 0x2305e33b, GSW_REG_MAC_P0_MCR);
 		mt7530_mdio_w32(gsw, 0x3600, 0x5e33b);
 	}
 
 	/* (GE2, Link down) */
-	mtk_switch_w32(gsw, 0x8000, 0x200);
+	mtk_switch_w32(gsw, 0x8000, GSW_REG_MAC_P1_MCR);
+
+	/* Set switch max RX frame length to 2k */
+	mt7530_mdio_w32(gsw, GSW_REG_GMACCR, 0x3F0B);
 
 	/* Enable Port 6, P5 as GMAC5, P5 disable */
 	val = mt7530_mdio_r32(gsw, 0x7804);

target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/mtk_eth_soc.c

@@ -1350,6 +1350,10 @@ static int fe_change_mtu(struct net_device *dev, int new_mtu)
 	if (!(priv->flags & FE_FLAG_JUMBO_FRAME))
 		return eth_change_mtu(dev, new_mtu);
 
+	if (IS_ENABLED(CONFIG_SOC_MT7621))
+		if (new_mtu > 2048)
+			return -EINVAL;
+
 	frag_size = fe_max_frag_size(new_mtu);
 	if (new_mtu < 68 || frag_size > PAGE_SIZE)
 		return -EINVAL;
@@ -1373,15 +1377,17 @@ static int fe_change_mtu(struct net_device *dev, int new_mtu)
 		return 0;
 
 	fe_stop(dev);
-	fwd_cfg = fe_r32(FE_GDMA1_FWD_CFG);
-	if (new_mtu <= ETH_DATA_LEN) {
-		fwd_cfg &= ~FE_GDM1_JMB_EN;
-	} else {
-		fwd_cfg &= ~(FE_GDM1_JMB_LEN_MASK << FE_GDM1_JMB_LEN_SHIFT);
-		fwd_cfg |= (DIV_ROUND_UP(frag_size, 1024) <<
-				FE_GDM1_JMB_LEN_SHIFT) | FE_GDM1_JMB_EN;
+	if (!IS_ENABLED(CONFIG_SOC_MT7621)) {
+		fwd_cfg = fe_r32(FE_GDMA1_FWD_CFG);
+		if (new_mtu <= ETH_DATA_LEN) {
+			fwd_cfg &= ~FE_GDM1_JMB_EN;
+		} else {
+			fwd_cfg &= ~(FE_GDM1_JMB_LEN_MASK << FE_GDM1_JMB_LEN_SHIFT);
+			fwd_cfg |= (DIV_ROUND_UP(frag_size, 1024) <<
+			FE_GDM1_JMB_LEN_SHIFT) | FE_GDM1_JMB_EN;
+		}
+		fe_w32(fwd_cfg, FE_GDMA1_FWD_CFG);
 	}
-	fe_w32(fwd_cfg, FE_GDMA1_FWD_CFG);
 
 	return fe_open(dev);
 }

target/linux/ramips/files-4.9/drivers/net/ethernet/mtk/soc_mt7621.c

@@ -139,7 +139,7 @@ static void mt7621_init_data(struct fe_soc_data *data,
 
 	priv->flags = FE_FLAG_PADDING_64B | FE_FLAG_RX_2B_OFFSET |
 		FE_FLAG_RX_SG_DMA | FE_FLAG_NAPI_WEIGHT |
-		FE_FLAG_HAS_SWITCH;
+		FE_FLAG_HAS_SWITCH | FE_FLAG_JUMBO_FRAME;
 
 	netdev->hw_features = NETIF_F_IP_CSUM | NETIF_F_RXCSUM |
 		NETIF_F_HW_VLAN_CTAG_TX | NETIF_F_SG | NETIF_F_TSO |