net: ethernet: mediatek: add the whole ethernet reset into the reset process

1) original driver only resets DMA used by descriptor rings
which can't guarantee it can recover all various kinds of fatal
errors, so the patch tries to reset the underlying hardware
resource from scratch on Mediatek SoC required for ethernet
running, including power, pin mux control, clock and internal
circuits on the ethernet in order to restore into the initial
state which the rebooted machine gives.

2) add state variable inside structure mtk_eth to help distinguish
mtk_hw_init is called between the initialization during boot time
or re-initialization during the reset process.

3) add ge_mode variable inside structure mtk_mac for restoring
the interface mode of the current setup for the target MAC.

4) remove __init attribute from mtk_hw_init definition

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 43 insertions, 8 deletions

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 01f59115132c..7b2f5edf274a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -231,7 +231,7 @@ static int mtk_phy_connect(struct mtk_mac *mac)
 {
 	struct mtk_eth *eth = mac->hw;
 	struct device_node *np;
-	u32 val, ge_mode;
+	u32 val;
 
 	np = of_parse_phandle(mac->of_node, "phy-handle", 0);
 	if (!np && of_phy_is_fixed_link(mac->of_node))
@@ -245,18 +245,18 @@ static int mtk_phy_connect(struct mtk_mac *mac)
 	case PHY_INTERFACE_MODE_RGMII_RXID:
 	case PHY_INTERFACE_MODE_RGMII_ID:
 	case PHY_INTERFACE_MODE_RGMII:
-		ge_mode = 0;
+		mac->ge_mode = 0;
 		break;
 	case PHY_INTERFACE_MODE_MII:
-		ge_mode = 1;
+		mac->ge_mode = 1;
 		break;
 	case PHY_INTERFACE_MODE_REVMII:
-		ge_mode = 2;
+		mac->ge_mode = 2;
 		break;
 	case PHY_INTERFACE_MODE_RMII:
 		if (!mac->id)
 			goto err_phy;
-		ge_mode = 3;
+		mac->ge_mode = 3;
 		break;
 	default:
 		goto err_phy;
@@ -265,7 +265,7 @@ static int mtk_phy_connect(struct mtk_mac *mac)
 	/* put the gmac into the right mode */
 	regmap_read(eth->ethsys, ETHSYS_SYSCFG0, &val);
 	val &= ~SYSCFG0_GE_MODE(SYSCFG0_GE_MASK, mac->id);
-	val |= SYSCFG0_GE_MODE(ge_mode, mac->id);
+	val |= SYSCFG0_GE_MODE(mac->ge_mode, mac->id);
 	regmap_write(eth->ethsys, ETHSYS_SYSCFG0, val);
 
 	mtk_phy_connect_node(eth, mac, np);
@@ -1414,9 +1414,12 @@ static int mtk_stop(struct net_device *dev)
 	return 0;
 }
 
-static int __init mtk_hw_init(struct mtk_eth *eth)
+static int mtk_hw_init(struct mtk_eth *eth)
 {
-	int i;
+	int i, val;
+
+	if (test_and_set_bit(MTK_HW_INIT, &eth->state))
+		return 0;
 
 	pm_runtime_enable(eth->dev);
 	pm_runtime_get_sync(eth->dev);
@@ -1432,6 +1435,15 @@ static int __init mtk_hw_init(struct mtk_eth *eth)
 	reset_control_deassert(eth->rstc);
 	usleep_range(10, 20);
 
+	regmap_read(eth->ethsys, ETHSYS_SYSCFG0, &val);
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!eth->mac[i])
+			continue;
+		val &= ~SYSCFG0_GE_MODE(SYSCFG0_GE_MASK, eth->mac[i]->id);
+		val |= SYSCFG0_GE_MODE(eth->mac[i]->ge_mode, eth->mac[i]->id);
+	}
+	regmap_write(eth->ethsys, ETHSYS_SYSCFG0, val);
+
 	/* Set GE2 driving and slew rate */
 	regmap_write(eth->pctl, GPIO_DRV_SEL10, 0xa00);
 
@@ -1483,6 +1495,9 @@ static int __init mtk_hw_init(struct mtk_eth *eth)
 
 static int mtk_hw_deinit(struct mtk_eth *eth)
 {
+	if (!test_and_clear_bit(MTK_HW_INIT, &eth->state))
+		return 0;
+
 	clk_disable_unprepare(eth->clks[MTK_CLK_GP2]);
 	clk_disable_unprepare(eth->clks[MTK_CLK_GP1]);
 	clk_disable_unprepare(eth->clks[MTK_CLK_ESW]);
@@ -1560,6 +1575,26 @@ static void mtk_pending_work(struct work_struct *work)
 		__set_bit(i, &restart);
 	}
 
+	/* restart underlying hardware such as power, clock, pin mux
+	 * and the connected phy
+	 */
+	mtk_hw_deinit(eth);
+
+	if (eth->dev->pins)
+		pinctrl_select_state(eth->dev->pins->p,
+				     eth->dev->pins->default_state);
+	mtk_hw_init(eth);
+
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!eth->mac[i] ||
+		    of_phy_is_fixed_link(eth->mac[i]->of_node))
+			continue;
+		err = phy_init_hw(eth->mac[i]->phy_dev);
+		if (err)
+			dev_err(eth->dev, "%s: PHY init failed.\n",
+				eth->netdev[i]->name);
+	}
+
 	/* restart DMA and enable IRQs */
 	for (i = 0; i < MTK_MAC_COUNT; i++) {
 		if (!test_bit(i, &restart))