[PATCH net-next v2 0/7] add enhancement into the existing reset flow

[PATCH net-next v2 0/7] add enhancement into the existing reset flow

[sean.wang]

From: Sean Wang <sean.wang@mediatek.com>

Current driver only resets DMA used by descriptor rings which
can't guarantee it can recover all various kinds of fatal
errors, so the patch
1) tries to reset the underlying hardware resource from scratch on
Mediatek SoC required for ethernet running.
2) refactors code in order to the reusability of existing code.
3) considers handling for race condition between the reset flow and
callbacks registered into core driver called about hardware accessing.
4) introduces power domain usage to hardware setup which leads to have
cleanly and completely restore to the state as the initial.

Changes since v1:
- fix the build error with module built causing undefined symbol for
  pinctrl_bind_pins, so using pinctrl_select_state instead accomplishes
  the pin mux setup during the reset process.

Sean Wang (7):
  net: ethernet: mediatek: refactoring mtk_hw_init to be reused
  net: ethernet: mediatek: add mtk_hw_deinit call as the opposite to
    mtk_hw_init call
  net: ethernet: mediatek: cleanup error path inside mtk_hw_init
  net: ethernet: mediatek: add controlling power domain the ethernet
    belongs to
  net: ethernet: mediatek: add the whole ethernet reset into the reset
    process
  net: ethernet: mediatek: add more resets for internal ethernet circuit
    block
  net: ethernet: mediatek: avoid race condition during the reset process

 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 226 +++++++++++++++++++++-------
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  15 +-
 2 files changed, 186 insertions(+), 55 deletions(-)

-- 
1.9.1

[PATCH net-next v2 1/7] net: ethernet: mediatek: refactoring mtk_hw_init to be reused

[sean.wang]

From: Sean Wang <sean.wang@mediatek.com>

the existing mtk_hw_init includes hardware and software
initialization inside so that it is slightly hard to reuse
them for the process of the reset recovery, so some splitting
is made here for keeping hardware initializing relevant thing
and the else such as IRQ registration and MDIO initialization
what are all about to the interface of core driver moved to the
other proper place because they have no needs to register IRQ and
re-initialize structure again during the reset process.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 62 ++++++++++++++++-------------
 1 file changed, 34 insertions(+), 28 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 66fd45a..ca46e82 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1415,7 +1415,12 @@ static int mtk_stop(struct net_device *dev)
 
 static int __init mtk_hw_init(struct mtk_eth *eth)
 {
-	int err, i;
+	int i;
+
+	clk_prepare_enable(eth->clks[MTK_CLK_ETHIF]);
+	clk_prepare_enable(eth->clks[MTK_CLK_ESW]);
+	clk_prepare_enable(eth->clks[MTK_CLK_GP1]);
+	clk_prepare_enable(eth->clks[MTK_CLK_GP2]);
 
 	/* reset the frame engine */
 	reset_control_assert(eth->rstc);
@@ -1441,19 +1446,6 @@ static int __init mtk_hw_init(struct mtk_eth *eth)
 	/* Enable RX VLan Offloading */
 	mtk_w32(eth, 1, MTK_CDMP_EG_CTRL);
 
-	err = devm_request_irq(eth->dev, eth->irq[1], mtk_handle_irq_tx, 0,
-			       dev_name(eth->dev), eth);
-	if (err)
-		return err;
-	err = devm_request_irq(eth->dev, eth->irq[2], mtk_handle_irq_rx, 0,
-			       dev_name(eth->dev), eth);
-	if (err)
-		return err;
-
-	err = mtk_mdio_init(eth);
-	if (err)
-		return err;
-
 	/* disable delay and normal interrupt */
 	mtk_w32(eth, 0, MTK_QDMA_DELAY_INT);
 	mtk_w32(eth, 0, MTK_PDMA_DELAY_INT);
@@ -1783,16 +1775,7 @@ static int mtk_add_mac(struct mtk_eth *eth, struct device_node *np)
 	eth->netdev[id]->features |= MTK_HW_FEATURES;
 	eth->netdev[id]->ethtool_ops = &mtk_ethtool_ops;
 
-	err = register_netdev(eth->netdev[id]);
-	if (err) {
-		dev_err(eth->dev, "error bringing up device\n");
-		goto free_netdev;
-	}
 	eth->netdev[id]->irq = eth->irq[0];
-	netif_info(eth, probe, eth->netdev[id],
-		   "mediatek frame engine at 0x%08lx, irq %d\n",
-		   eth->netdev[id]->base_addr, eth->irq[0]);
-
 	return 0;
 
 free_netdev:
@@ -1862,11 +1845,6 @@ static int mtk_probe(struct platform_device *pdev)
 		}
 	}
 
-	clk_prepare_enable(eth->clks[MTK_CLK_ETHIF]);
-	clk_prepare_enable(eth->clks[MTK_CLK_ESW]);
-	clk_prepare_enable(eth->clks[MTK_CLK_GP1]);
-	clk_prepare_enable(eth->clks[MTK_CLK_GP2]);
-
 	eth->msg_enable = netif_msg_init(mtk_msg_level, MTK_DEFAULT_MSG_ENABLE);
 	INIT_WORK(&eth->pending_work, mtk_pending_work);
 
@@ -1887,6 +1865,34 @@ static int mtk_probe(struct platform_device *pdev)
 			goto err_free_dev;
 	}
 
+	err = devm_request_irq(eth->dev, eth->irq[1], mtk_handle_irq_tx, 0,
+			       dev_name(eth->dev), eth);
+	if (err)
+		goto err_free_dev;
+
+	err = devm_request_irq(eth->dev, eth->irq[2], mtk_handle_irq_rx, 0,
+			       dev_name(eth->dev), eth);
+	if (err)
+		goto err_free_dev;
+
+	err = mtk_mdio_init(eth);
+	if (err)
+		goto err_free_dev;
+
+	for (i = 0; i < MTK_MAX_DEVS; i++) {
+		if (!eth->netdev[i])
+			continue;
+
+		err = register_netdev(eth->netdev[i]);
+		if (err) {
+			dev_err(eth->dev, "error bringing up device\n");
+			goto err_free_dev;
+		} else
+			netif_info(eth, probe, eth->netdev[i],
+				   "mediatek frame engine at 0x%08lx, irq %d\n",
+				   eth->netdev[i]->base_addr, eth->irq[0]);
+	}
+
 	/* we run 2 devices on the same DMA ring so we need a dummy device
 	 * for NAPI to work
 	 */
-- 
1.9.1

[PATCH net-next v2 2/7] net: ethernet: mediatek: add mtk_hw_deinit call as the opposite to mtk_hw_init call

[sean.wang]

From: Sean Wang <sean.wang@mediatek.com>

grouping things related to the deinitialization of what
mtk_hw_init call does that help to be reused by the reset
process and the error path handling.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index ca46e82..c71b0b3 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1477,6 +1477,16 @@ static int __init mtk_hw_init(struct mtk_eth *eth)
 	return 0;
 }
 
+static int mtk_hw_deinit(struct mtk_eth *eth)
+{
+	clk_disable_unprepare(eth->clks[MTK_CLK_GP2]);
+	clk_disable_unprepare(eth->clks[MTK_CLK_GP1]);
+	clk_disable_unprepare(eth->clks[MTK_CLK_ESW]);
+	clk_disable_unprepare(eth->clks[MTK_CLK_ETHIF]);
+
+	return 0;
+}
+
 static int __init mtk_init(struct net_device *dev)
 {
 	struct mtk_mac *mac = netdev_priv(dev);
@@ -1923,10 +1933,7 @@ static int mtk_remove(struct platform_device *pdev)
 		mtk_stop(eth->netdev[i]);
 	}
 
-	clk_disable_unprepare(eth->clks[MTK_CLK_ETHIF]);
-	clk_disable_unprepare(eth->clks[MTK_CLK_ESW]);
-	clk_disable_unprepare(eth->clks[MTK_CLK_GP1]);
-	clk_disable_unprepare(eth->clks[MTK_CLK_GP2]);
+	mtk_hw_deinit(eth);
 
 	netif_napi_del(&eth->tx_napi);
 	netif_napi_del(&eth->rx_napi);
-- 
1.9.1

[PATCH net-next v2 4/7] net: ethernet: mediatek: add controlling power domain the ethernet belongs to

[sean.wang]

From: Sean Wang <sean.wang@mediatek.com>

introduce power domain control which the digital circuit of
the ethernet belongs to inside the flow of hardware initialization
and deinitialization which helps the entire ethernet hardware block
could restart cleanly and completely as being back to the initial
state when the whole machine reboot.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index 917a49c6..fd5d064 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -18,6 +18,7 @@
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 #include <linux/clk.h>
+#include <linux/pm_runtime.h>
 #include <linux/if_vlan.h>
 #include <linux/reset.h>
 #include <linux/tcp.h>
@@ -1417,6 +1418,9 @@ static int __init mtk_hw_init(struct mtk_eth *eth)
 {
 	int i;
 
+	pm_runtime_enable(eth->dev);
+	pm_runtime_get_sync(eth->dev);
+
 	clk_prepare_enable(eth->clks[MTK_CLK_ETHIF]);
 	clk_prepare_enable(eth->clks[MTK_CLK_ESW]);
 	clk_prepare_enable(eth->clks[MTK_CLK_GP1]);
@@ -1484,6 +1488,9 @@ static int mtk_hw_deinit(struct mtk_eth *eth)
 	clk_disable_unprepare(eth->clks[MTK_CLK_ESW]);
 	clk_disable_unprepare(eth->clks[MTK_CLK_ETHIF]);
 
+	pm_runtime_put_sync(eth->dev);
+	pm_runtime_disable(eth->dev);
+
 	return 0;
 }
 
-- 
1.9.1

[PATCH net-next v2 5/7] net: ethernet: mediatek: add the whole ethernet reset into the reset process

[sean.wang]

From: Sean Wang <sean.wang@mediatek.com>

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>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 51 ++++++++++++++++++++++++-----
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  8 +++++
 2 files changed, 51 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index fd5d064..a7e2e77 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]);
@@ -1557,6 +1572,26 @@ 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))
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 0b984dc..388cbe7 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -330,6 +330,10 @@ enum mtk_clks_map {
 	MTK_CLK_MAX
 };
 
+enum mtk_dev_state {
+	MTK_HW_INIT
+};
+
 /* struct mtk_tx_buf -	This struct holds the pointers to the memory pointed at
  *			by the TX descriptor	s
  * @skb:		The SKB pointer of the packet being sent
@@ -413,6 +417,7 @@ struct mtk_rx_ring {
  * @clks:		clock array for all clocks required
  * @mii_bus:		If there is a bus we need to create an instance for it
  * @pending_work:	The workqueue used to reset the dma ring
+ * @state               Initialization and runtime state of the device.
  */
 
 struct mtk_eth {
@@ -441,11 +446,13 @@ struct mtk_eth {
 
 	struct mii_bus			*mii_bus;
 	struct work_struct		pending_work;
+	unsigned long			state;
 };
 
 /* struct mtk_mac -	the structure that holds the info about the MACs of the
  *			SoC
  * @id:			The number of the MAC
+ * @ge_mode:            Interface mode kept for setup restoring
  * @of_node:		Our devicetree node
  * @hw:			Backpointer to our main datastruture
  * @hw_stats:		Packet statistics counter
@@ -453,6 +460,7 @@ struct mtk_eth {
  */
 struct mtk_mac {
 	int				id;
+	int				ge_mode;
 	struct device_node		*of_node;
 	struct mtk_eth			*hw;
 	struct mtk_hw_stats		*hw_stats;
-- 
1.9.1

[PATCH net-next v2 6/7] net: ethernet: mediatek: add more resets for internal ethernet circuit block

[sean.wang]

From: Sean Wang <sean.wang@mediatek.com>

struct mtk_eth has already contained struct regmap ethsys pointer
to the address range of the internal circuit reset, so we reuse it
to reset more internal blocks on ethernet hardware such as packet
processing engine (PPE) and frame engine (FE) instead of rstc which
deals with FE only.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 27 +++++++++++++++------------
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  6 +++++-
 2 files changed, 20 insertions(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index a7e2e77..cde9cd6 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1414,6 +1414,19 @@ static int mtk_stop(struct net_device *dev)
 	return 0;
 }
 
+static void ethsys_reset(struct mtk_eth *eth, u32 reset_bits)
+{
+	regmap_update_bits(eth->ethsys, ETHSYS_RSTCTRL,
+			   reset_bits,
+			   reset_bits);
+
+	usleep_range(1000, 1100);
+	regmap_update_bits(eth->ethsys, ETHSYS_RSTCTRL,
+			   reset_bits,
+			   ~reset_bits);
+	mdelay(10);
+}
+
 static int mtk_hw_init(struct mtk_eth *eth)
 {
 	int i, val;
@@ -1428,12 +1441,8 @@ static int mtk_hw_init(struct mtk_eth *eth)
 	clk_prepare_enable(eth->clks[MTK_CLK_ESW]);
 	clk_prepare_enable(eth->clks[MTK_CLK_GP1]);
 	clk_prepare_enable(eth->clks[MTK_CLK_GP2]);
-
-	/* reset the frame engine */
-	reset_control_assert(eth->rstc);
-	usleep_range(10, 20);
-	reset_control_deassert(eth->rstc);
-	usleep_range(10, 20);
+	ethsys_reset(eth, RSTCTRL_FE);
+	ethsys_reset(eth, RSTCTRL_PPE);
 
 	regmap_read(eth->ethsys, ETHSYS_SYSCFG0, &val);
 	for (i = 0; i < MTK_MAC_COUNT; i++) {
@@ -1893,12 +1902,6 @@ static int mtk_probe(struct platform_device *pdev)
 		return PTR_ERR(eth->pctl);
 	}
 
-	eth->rstc = devm_reset_control_get(&pdev->dev, "eth");
-	if (IS_ERR(eth->rstc)) {
-		dev_err(&pdev->dev, "no eth reset found\n");
-		return PTR_ERR(eth->rstc);
-	}
-
 	for (i = 0; i < 3; i++) {
 		eth->irq[i] = platform_get_irq(pdev, i);
 		if (eth->irq[i] < 0) {
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 388cbe7..7efa00f 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -266,6 +266,11 @@
 #define SYSCFG0_GE_MASK		0x3
 #define SYSCFG0_GE_MODE(x, y)	(x << (12 + (y * 2)))
 
+/*ethernet reset control register*/
+#define ETHSYS_RSTCTRL		0x34
+#define RSTCTRL_FE		BIT(6)
+#define RSTCTRL_PPE		BIT(31)
+
 struct mtk_rx_dma {
 	unsigned int rxd1;
 	unsigned int rxd2;
@@ -423,7 +428,6 @@ struct mtk_rx_ring {
 struct mtk_eth {
 	struct device			*dev;
 	void __iomem			*base;
-	struct reset_control		*rstc;
 	spinlock_t			page_lock;
 	spinlock_t			irq_lock;
 	struct net_device		dummy_dev;
-- 
1.9.1

[PATCH net-next v2 7/7] net: ethernet: mediatek: avoid race condition during the reset process

[sean.wang]

From: Sean Wang <sean.wang@mediatek.com>

add the protection of the race condition between
the reset process and hardware access happening
on the related callbacks.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 36 +++++++++++++++++++++++++++++
 drivers/net/ethernet/mediatek/mtk_eth_soc.h |  3 ++-
 2 files changed, 38 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index cde9cd6..b46b08a 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -145,6 +145,9 @@ static void mtk_phy_link_adjust(struct net_device *dev)
 		  MAC_MCR_RX_EN | MAC_MCR_BACKOFF_EN |
 		  MAC_MCR_BACKPR_EN;
 
+	if (unlikely(test_bit(MTK_RESETTING, &mac->hw->state)))
+		return;
+
 	switch (mac->phy_dev->speed) {
 	case SPEED_1000:
 		mcr |= MAC_MCR_SPEED_1000;
@@ -370,6 +373,9 @@ static int mtk_set_mac_address(struct net_device *dev, void *p)
 	if (ret)
 		return ret;
 
+	if (unlikely(test_bit(MTK_RESETTING, &mac->hw->state)))
+		return -EBUSY;
+
 	spin_lock_bh(&mac->hw->page_lock);
 	mtk_w32(mac->hw, (macaddr[0] << 8) | macaddr[1],
 		MTK_GDMA_MAC_ADRH(mac->id));
@@ -770,6 +776,9 @@ static int mtk_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	 */
 	spin_lock(&eth->page_lock);
 
+	if (unlikely(test_bit(MTK_RESETTING, &eth->state)))
+		goto drop;
+
 	tx_num = mtk_cal_txd_req(skb);
 	if (unlikely(atomic_read(&ring->free_count) <= tx_num)) {
 		mtk_stop_queue(eth);
@@ -842,6 +851,9 @@ static int mtk_poll_rx(struct napi_struct *napi, int budget,
 
 		netdev = eth->netdev[mac];
 
+		if (unlikely(test_bit(MTK_RESETTING, &eth->state)))
+			goto release_desc;
+
 		/* alloc new buffer */
 		new_data = napi_alloc_frag(ring->frag_size);
 		if (unlikely(!new_data)) {
@@ -1573,6 +1585,12 @@ static void mtk_pending_work(struct work_struct *work)
 
 	rtnl_lock();
 
+	dev_dbg(eth->dev, "[%s][%d] reset\n", __func__, __LINE__);
+
+	while (test_and_set_bit_lock(MTK_RESETTING, &eth->state))
+		cpu_relax();
+
+	dev_dbg(eth->dev, "[%s][%d] mtk_stop starts\n", __func__, __LINE__);
 	/* stop all devices to make sure that dma is properly shut down */
 	for (i = 0; i < MTK_MAC_COUNT; i++) {
 		if (!eth->netdev[i])
@@ -1580,6 +1598,7 @@ static void mtk_pending_work(struct work_struct *work)
 		mtk_stop(eth->netdev[i]);
 		__set_bit(i, &restart);
 	}
+	dev_dbg(eth->dev, "[%s][%d] mtk_stop ends\n", __func__, __LINE__);
 
 	/* restart underlying hardware such as power, clock, pin mux
 	 * and the connected phy
@@ -1612,6 +1631,11 @@ static void mtk_pending_work(struct work_struct *work)
 			dev_close(eth->netdev[i]);
 		}
 	}
+
+	dev_dbg(eth->dev, "[%s][%d] reset done\n", __func__, __LINE__);
+
+	clear_bit_unlock(MTK_RESETTING, &eth->state);
+
 	rtnl_unlock();
 }
 
@@ -1656,6 +1680,9 @@ static int mtk_get_settings(struct net_device *dev,
 	struct mtk_mac *mac = netdev_priv(dev);
 	int err;
 
+	if (unlikely(test_bit(MTK_RESETTING, &mac->hw->state)))
+		return -EBUSY;
+
 	err = phy_read_status(mac->phy_dev);
 	if (err)
 		return -ENODEV;
@@ -1706,6 +1733,9 @@ static int mtk_nway_reset(struct net_device *dev)
 {
 	struct mtk_mac *mac = netdev_priv(dev);
 
+	if (unlikely(test_bit(MTK_RESETTING, &mac->hw->state)))
+		return -EBUSY;
+
 	return genphy_restart_aneg(mac->phy_dev);
 }
 
@@ -1714,6 +1744,9 @@ static u32 mtk_get_link(struct net_device *dev)
 	struct mtk_mac *mac = netdev_priv(dev);
 	int err;
 
+	if (unlikely(test_bit(MTK_RESETTING, &mac->hw->state)))
+		return -EBUSY;
+
 	err = genphy_update_link(mac->phy_dev);
 	if (err)
 		return ethtool_op_get_link(dev);
@@ -1754,6 +1787,9 @@ static void mtk_get_ethtool_stats(struct net_device *dev,
 	unsigned int start;
 	int i;
 
+	if (unlikely(test_bit(MTK_RESETTING, &mac->hw->state)))
+		return;
+
 	if (netif_running(dev) && netif_device_present(dev)) {
 		if (spin_trylock(&hwstats->stats_lock)) {
 			mtk_stats_update_mac(mac);
diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.h b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
index 7efa00f..79954b4 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.h
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.h
@@ -336,7 +336,8 @@ enum mtk_clks_map {
 };
 
 enum mtk_dev_state {
-	MTK_HW_INIT
+	MTK_HW_INIT,
+	MTK_RESETTING
 };
 
 /* struct mtk_tx_buf -	This struct holds the pointers to the memory pointed at
-- 
1.9.1

[PATCH net-next v2 3/7] net: ethernet: mediatek: cleanup error path inside mtk_hw_init

[sean.wang-NuS5LvNUpcJWk0Htik3J/w]

From: Sean Wang <sean.wang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>

This cleans up the error path inside mtk_hw_init call, causing it able
to exit appropriately when something fails and also includes refactoring
mtk_cleanup call to make the partial logic reusable on the error path.

Signed-off-by: Sean Wang <sean.wang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
---
 drivers/net/ethernet/mediatek/mtk_eth_soc.c | 34 ++++++++++++++++++++++++-----
 1 file changed, 29 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/mediatek/mtk_eth_soc.c b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
index c71b0b3..917a49c6 100644
--- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c
+++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c
@@ -1564,17 +1564,36 @@ static void mtk_pending_work(struct work_struct *work)
 	rtnl_unlock();
 }
 
-static int mtk_cleanup(struct mtk_eth *eth)
+static int mtk_free_dev(struct mtk_eth *eth)
 {
 	int i;
 
 	for (i = 0; i < MTK_MAC_COUNT; i++) {
 		if (!eth->netdev[i])
 			continue;
+		free_netdev(eth->netdev[i]);
+	}
+
+	return 0;
+}
 
+static int mtk_unreg_dev(struct mtk_eth *eth)
+{
+	int i;
+
+	for (i = 0; i < MTK_MAC_COUNT; i++) {
+		if (!eth->netdev[i])
+			continue;
 		unregister_netdev(eth->netdev[i]);
-		free_netdev(eth->netdev[i]);
 	}
+
+	return 0;
+}
+
+static int mtk_cleanup(struct mtk_eth *eth)
+{
+	mtk_unreg_dev(eth);
+	mtk_free_dev(eth);
 	cancel_work_sync(&eth->pending_work);
 
 	return 0;
@@ -1872,7 +1891,7 @@ static int mtk_probe(struct platform_device *pdev)
 
 		err = mtk_add_mac(eth, mac_np);
 		if (err)
-			goto err_free_dev;
+			goto err_deinit_hw;
 	}
 
 	err = devm_request_irq(eth->dev, eth->irq[1], mtk_handle_irq_tx, 0,
@@ -1896,7 +1915,7 @@ static int mtk_probe(struct platform_device *pdev)
 		err = register_netdev(eth->netdev[i]);
 		if (err) {
 			dev_err(eth->dev, "error bringing up device\n");
-			goto err_free_dev;
+			goto err_deinit_mdio;
 		} else
 			netif_info(eth, probe, eth->netdev[i],
 				   "mediatek frame engine at 0x%08lx, irq %d\n",
@@ -1916,8 +1935,13 @@ static int mtk_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_deinit_mdio:
+	mtk_mdio_cleanup(eth);
 err_free_dev:
-	mtk_cleanup(eth);
+	mtk_free_dev(eth);
+err_deinit_hw:
+	mtk_hw_deinit(eth);
+
 	return err;
 }
 
-- 
1.9.1

Re: [PATCH net-next v2 0/7] add enhancement into the existing reset flow

[David Miller]

From: <sean.wang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
Date: Wed, 14 Sep 2016 23:13:14 +0800

> From: Sean Wang <sean.wang-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org>
> 
> Current driver only resets DMA used by descriptor rings which
> can't guarantee it can recover all various kinds of fatal
> errors, so the patch
> 1) tries to reset the underlying hardware resource from scratch on
> Mediatek SoC required for ethernet running.
> 2) refactors code in order to the reusability of existing code.
> 3) considers handling for race condition between the reset flow and
> callbacks registered into core driver called about hardware accessing.
> 4) introduces power domain usage to hardware setup which leads to have
> cleanly and completely restore to the state as the initial.
> 
> Changes since v1:
> - fix the build error with module built causing undefined symbol for
>   pinctrl_bind_pins, so using pinctrl_select_state instead accomplishes
>   the pin mux setup during the reset process.

Series applied, thanks.