[PATCH 1/2] net: phy: Add error checks in the driver

Subsystems: ethernet phy library, networking drivers, the rest

STALE3650d

5 messages, 2 authors, 2016-08-19 · open the first message on its own page

[PATCH 1/2] net: phy: Add error checks in the driver

From: Kedareswara rao Appana <appana.durga.rao@xilinx.com>
Date: 2016-08-19 12:49:55

This patch adds the necessary error checks in the driver.

Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Kedareswara rao Appana <redacted>
---
 drivers/net/phy/xilinx_gmii2rgmii.c | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c b/drivers/net/phy/xilinx_gmii2rgmii.c
index e7a20ec..7336fd0 100644
--- a/drivers/net/phy/xilinx_gmii2rgmii.c
+++ b/drivers/net/phy/xilinx_gmii2rgmii.c

@@ -39,11 +39,16 @@ struct gmii2rgmii {
 static int xgmiitorgmii_read_status(struct phy_device *phydev)
 {
 	struct gmii2rgmii *priv = phydev->priv;
-	u16 val = 0;
+	int err, val = 0;
 
-	priv->phy_drv->read_status(phydev);
+	err = priv->phy_drv->read_status(phydev);
+	if (err < 0)
+		return err;
 
 	val = mdiobus_read(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG);
+	if (val < 0)
+		return val;
+
 	val &= XILINX_GMII2RGMII_SPEED_MASK;
 
 	if (phydev->speed == SPEED_1000)

@@ -53,7 +58,10 @@ static int xgmiitorgmii_read_status(struct phy_device *phydev)
 	else
 		val |= BMCR_SPEED10;
 
-	mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG, val);
+	err = mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG,
+			    val);
+	if (err < 0)
+		return err;
 
 	return 0;
 }

-- 
2.1.2

[PATCH 2/2] net: phy: Fix race conditions in the driver

From: Kedareswara rao Appana <appana.durga.rao@xilinx.com>
Date: 2016-08-19 12:49:58

This patch fixes the below race conditions in the driver.
---> Fix Opps after unload the driver as a module
---> Use spin locks where relevant.
---> Take reference on the external phy to prevent issues
when phy driver is unloaded.

Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Kedareswara rao Appana <redacted>
---
 drivers/net/phy/xilinx_gmii2rgmii.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c b/drivers/net/phy/xilinx_gmii2rgmii.c
index 7336fd0..cdd9d95 100644
--- a/drivers/net/phy/xilinx_gmii2rgmii.c
+++ b/drivers/net/phy/xilinx_gmii2rgmii.c

@@ -34,6 +34,7 @@ struct gmii2rgmii {
 	struct phy_driver *phy_drv;
 	struct phy_driver conv_phy_drv;
 	int addr;
+	spinlock_t phy_lock;
 };
 
 static int xgmiitorgmii_read_status(struct phy_device *phydev)

@@ -55,7 +56,7 @@ static int xgmiitorgmii_read_status(struct phy_device *phydev)
 		val |= BMCR_SPEED1000;
 	else if (phydev->speed == SPEED_100)
 		val |= BMCR_SPEED100;
-	else
+	else if (phydev->speed == SPEED_10)
 		val |= BMCR_SPEED10;
 
 	err = mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG,

@@ -71,6 +72,8 @@ int xgmiitorgmii_probe(struct mdio_device *mdiodev)
 	struct device *dev = &mdiodev->dev;
 	struct device_node *np = dev->of_node, *phy_node;
 	struct gmii2rgmii *priv;
+	struct mii_bus *bus;
+	unsigned long flags;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)

@@ -88,17 +91,43 @@ int xgmiitorgmii_probe(struct mdio_device *mdiodev)
 		return -EPROBE_DEFER;
 	}
 
+	spin_lock_init(&priv->phy_lock);
+
+	bus = priv->phy_dev->mdio.bus;
+	if (!try_module_get(bus->owner)) {
+		dev_err(dev, "failed to get the bus module\n");
+		return -EIO;
+	}
+
+	get_device(&priv->phy_dev->mdio.dev);
+
 	priv->addr = mdiodev->addr;
 	priv->phy_drv = priv->phy_dev->drv;
 	memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,
 	       sizeof(struct phy_driver));
 	priv->conv_phy_drv.read_status = xgmiitorgmii_read_status;
 	priv->phy_dev->priv = priv;
+	spin_lock_irqsave(&priv->phy_lock, flags);
 	priv->phy_dev->drv = &priv->conv_phy_drv;
+	spin_unlock_irqrestore(&priv->phy_lock, flags);
+
+	dev_set_drvdata(dev, priv);
 
 	return 0;
 }
 
+static void xgmiitorgmii_remove(struct mdio_device *mdiodev)
+{
+	struct gmii2rgmii *priv = dev_get_drvdata(&mdiodev->dev);
+	struct mii_bus *bus;
+
+	bus = priv->phy_dev->mdio.bus;
+
+	put_device(&priv->phy_dev->mdio.dev);
+	module_put(bus->owner);
+	phy_disconnect(priv->phy_dev);
+}
+
 static const struct of_device_id xgmiitorgmii_of_match[] = {
 	{ .compatible = "xlnx,gmii-to-rgmii-1.0" },
 	{},

@@ -107,6 +136,7 @@ MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
 
 static struct mdio_driver xgmiitorgmii_driver = {
 	.probe	= xgmiitorgmii_probe,
+	.remove	= xgmiitorgmii_remove,
 	.mdiodrv.driver = {
 		.name = "xgmiitorgmii",
 		.of_match_table = xgmiitorgmii_of_match,

-- 
2.1.2

Re: [PATCH 1/2] net: phy: Add error checks in the driver

From: Andrew Lunn <andrew@lunn.ch>
Date: 2016-08-19 13:15:26

-	mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG, val);
+	err = mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG,
+			    val);
+	if (err < 0)
+		return err;
 
 	return 0;

Do you need to assign err? Why not just

   return mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG,
			val);

Re: [PATCH 2/2] net: phy: Fix race conditions in the driver

From: Andrew Lunn <andrew@lunn.ch>
Date: 2016-08-19 13:24:26

On Fri, Aug 19, 2016 at 06:18:11PM +0530, Kedareswara rao Appana wrote:

This patch fixes the below race conditions in the driver.
---> Fix Opps after unload the driver as a module
---> Use spin locks where relevant.
---> Take reference on the external phy to prevent issues
when phy driver is unloaded.

Each one of these should be an individual patch.

quoted hunk

Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Kedareswara rao Appana <redacted>
---
 drivers/net/phy/xilinx_gmii2rgmii.c | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/drivers/net/phy/xilinx_gmii2rgmii.c b/drivers/net/phy/xilinx_gmii2rgmii.c
index 7336fd0..cdd9d95 100644
--- a/drivers/net/phy/xilinx_gmii2rgmii.c
+++ b/drivers/net/phy/xilinx_gmii2rgmii.c

@@ -34,6 +34,7 @@ struct gmii2rgmii {
 	struct phy_driver *phy_drv;
 	struct phy_driver conv_phy_drv;
 	int addr;
+	spinlock_t phy_lock;

The phy already have a lock.

quoted hunk

 };
 
 static int xgmiitorgmii_read_status(struct phy_device *phydev)

@@ -55,7 +56,7 @@ static int xgmiitorgmii_read_status(struct phy_device *phydev)
 		val |= BMCR_SPEED1000;
 	else if (phydev->speed == SPEED_100)
 		val |= BMCR_SPEED100;
-	else
+	else if (phydev->speed == SPEED_10)
 		val |= BMCR_SPEED10;

  
I said you want to return an error is the PHY is using a speed your
converter cannot support. I don't see an error being raised here.

quoted hunk

 	err = mdiobus_write(phydev->mdio.bus, priv->addr, XILINX_GMII2RGMII_REG,

@@ -71,6 +72,8 @@ int xgmiitorgmii_probe(struct mdio_device *mdiodev)
 	struct device *dev = &mdiodev->dev;
 	struct device_node *np = dev->of_node, *phy_node;
 	struct gmii2rgmii *priv;
+	struct mii_bus *bus;
+	unsigned long flags;
 
 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
 	if (!priv)
@@ -88,17 +91,43 @@ int xgmiitorgmii_probe(struct mdio_device *mdiodev)
 		return -EPROBE_DEFER;
 	}
 
+	spin_lock_init(&priv->phy_lock);
+
+	bus = priv->phy_dev->mdio.bus;
+	if (!try_module_get(bus->owner)) {
+		dev_err(dev, "failed to get the bus module\n");
+		return -EIO;
+	}

The comment at the top says you are taking a reference to the phy.
Here you take a reference to the mdio bus driver???

+
+	get_device(&priv->phy_dev->mdio.dev);
+
 	priv->addr = mdiodev->addr;
 	priv->phy_drv = priv->phy_dev->drv;
 	memcpy(&priv->conv_phy_drv, priv->phy_dev->drv,
 	       sizeof(struct phy_driver));
 	priv->conv_phy_drv.read_status = xgmiitorgmii_read_status;
 	priv->phy_dev->priv = priv;
+	spin_lock_irqsave(&priv->phy_lock, flags);
 	priv->phy_dev->drv = &priv->conv_phy_drv;
+	spin_unlock_irqrestore(&priv->phy_lock, flags);

And how is this spinlock protecting anything?

+
+	dev_set_drvdata(dev, priv);
 
 	return 0;
 }
 
+static void xgmiitorgmii_remove(struct mdio_device *mdiodev)
+{
+	struct gmii2rgmii *priv = dev_get_drvdata(&mdiodev->dev);
+	struct mii_bus *bus;
+
+	bus = priv->phy_dev->mdio.bus;
+
+	put_device(&priv->phy_dev->mdio.dev);
+	module_put(bus->owner);
+	phy_disconnect(priv->phy_dev);

Why are you disconnecting the phy?

quoted hunk

+}
+
 static const struct of_device_id xgmiitorgmii_of_match[] = {
 	{ .compatible = "xlnx,gmii-to-rgmii-1.0" },
 	{},

@@ -107,6 +136,7 @@ MODULE_DEVICE_TABLE(of, xgmiitorgmii_of_match);
 
 static struct mdio_driver xgmiitorgmii_driver = {
 	.probe	= xgmiitorgmii_probe,
+	.remove	= xgmiitorgmii_remove,
 	.mdiodrv.driver = {
 		.name = "xgmiitorgmii",
 		.of_match_table = xgmiitorgmii_of_match,

-- 
2.1.2

RE: [PATCH 1/2] net: phy: Add error checks in the driver

From: Appana Durga Kedareswara Rao <appana.durga.rao@xilinx.com>
Date: 2016-08-19 13:33:33

Hi Andrew,

	Thanks for the review...

quoted

-	mdiobus_write(phydev->mdio.bus, priv->addr,

XILINX_GMII2RGMII_REG, val);

quoted

+	err = mdiobus_write(phydev->mdio.bus, priv->addr,

XILINX_GMII2RGMII_REG,

quoted

+			    val);
+	if (err < 0)
+		return err;

 	return 0;

Do you need to assign err? Why not just

Ok will fix in the next version....

Regards,
Kedar.

   return mdiobus_write(phydev->mdio.bus, priv->addr,
XILINX_GMII2RGMII_REG,
			val);

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