[PATCH net-next] mdio_bus: Fix PTR_ERR() usage after initialization to constant

Subsystems: ethernet phy library, networking drivers, the rest

STALE2808d

5 messages, 3 authors, 2019-02-16 · open the first message on its own page

[PATCH net-next] mdio_bus: Fix PTR_ERR() usage after initialization to constant

From: YueHaibing <hidden>
Date: 2019-01-28 13:24:30

Fix coccinelle warning:

./drivers/net/phy/mdio_bus.c:51:5-12: ERROR: PTR_ERR applied after initialization to constant on line 44
./drivers/net/phy/mdio_bus.c:52:5-12: ERROR: PTR_ERR applied after initialization to constant on line 44

fix this by using IS_ERR before PTR_ERR

Fixes: bafbdd527d56 ("phylib: Add device reset GPIO support")
Signed-off-by: YueHaibing <redacted>
---
 drivers/net/phy/mdio_bus.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 3d31358..802716a 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c

@@ -42,17 +42,20 @@
 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
 {
 	struct gpio_desc *gpiod = NULL;
+	int ret;
 
 	/* Deassert the optional reset signal */
 	if (mdiodev->dev.of_node)
 		gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
 					       "reset-gpios", 0, GPIOD_OUT_LOW,
 					       "PHY reset");
-	if (PTR_ERR(gpiod) == -ENOENT ||
-	    PTR_ERR(gpiod) == -ENOSYS)
-		gpiod = NULL;
-	else if (IS_ERR(gpiod))
-		return PTR_ERR(gpiod);
+	if (IS_ERR(gpiod)) {
+		ret = PTR_ERR(gpiod);
+		if (ret == -ENOENT || ret == -ENOSYS)
+			gpiod = NULL;
+		else
+			return ret;
+	}
 
 	mdiodev->reset = gpiod;

-- 
2.7.4

Re: [PATCH net-next] mdio_bus: Fix PTR_ERR() usage after initialization to constant

From: Andrew Lunn <andrew@lunn.ch>
Date: 2019-01-28 14:36:50

On Mon, Jan 28, 2019 at 09:24:09PM +0800, YueHaibing wrote:

quoted hunk

Fix coccinelle warning:

./drivers/net/phy/mdio_bus.c:51:5-12: ERROR: PTR_ERR applied after initialization to constant on line 44
./drivers/net/phy/mdio_bus.c:52:5-12: ERROR: PTR_ERR applied after initialization to constant on line 44

fix this by using IS_ERR before PTR_ERR

Fixes: bafbdd527d56 ("phylib: Add device reset GPIO support")
Signed-off-by: YueHaibing <redacted>
---
 drivers/net/phy/mdio_bus.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 3d31358..802716a 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c

@@ -42,17 +42,20 @@
 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
 {
 	struct gpio_desc *gpiod = NULL;
+	int ret;

Hi YueHaibing

I think i prefer the simpler fix:

 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
 {
-  	struct gpio_desc *gpiod = NULL;
+       struct gpio_desc *gpiod = ERR_PTR(-ENOENT);

Totally untested...

	Andrew

 	/* Deassert the optional reset signal */
 	if (mdiodev->dev.of_node)
 		gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
 					       "reset-gpios", 0, GPIOD_OUT_LOW,
 					       "PHY reset");
-	if (PTR_ERR(gpiod) == -ENOENT ||
-	    PTR_ERR(gpiod) == -ENOSYS)
-		gpiod = NULL;
-	else if (IS_ERR(gpiod))
-		return PTR_ERR(gpiod);
+	if (IS_ERR(gpiod)) {
+		ret = PTR_ERR(gpiod);
+		if (ret == -ENOENT || ret == -ENOSYS)
+			gpiod = NULL;
+		else
+			return ret;
+	}
 
 	mdiodev->reset = gpiod;
 
-- 
2.7.4

Re: [PATCH net-next] mdio_bus: Fix PTR_ERR() usage after initialization to constant

From: YueHaibing <hidden>
Date: 2019-01-29 03:30:36

On 2019/1/28 22:36, Andrew Lunn wrote:

On Mon, Jan 28, 2019 at 09:24:09PM +0800, YueHaibing wrote:

quoted

Fix coccinelle warning:

./drivers/net/phy/mdio_bus.c:51:5-12: ERROR: PTR_ERR applied after initialization to constant on line 44
./drivers/net/phy/mdio_bus.c:52:5-12: ERROR: PTR_ERR applied after initialization to constant on line 44

fix this by using IS_ERR before PTR_ERR

Fixes: bafbdd527d56 ("phylib: Add device reset GPIO support")
Signed-off-by: YueHaibing <redacted>
---
 drivers/net/phy/mdio_bus.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/phy/mdio_bus.c b/drivers/net/phy/mdio_bus.c
index 3d31358..802716a 100644
--- a/drivers/net/phy/mdio_bus.c
+++ b/drivers/net/phy/mdio_bus.c

@@ -42,17 +42,20 @@
 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
 {
 	struct gpio_desc *gpiod = NULL;
+	int ret;

Hi YueHaibing

I think i prefer the simpler fix:

 static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
 {
-  	struct gpio_desc *gpiod = NULL;
+       struct gpio_desc *gpiod = ERR_PTR(-ENOENT);

But a56c69803f5a ("net: phy: Handle not having GPIO enabled in the kernel")
add a new check:

@@ -56,7 +56,8 @@ static int mdiobus_register_gpiod(struct mdio_device *mdiodev)
                gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
                                               "reset-gpios", 0, GPIOD_OUT_LOW,
                                               "PHY reset");
-       if (PTR_ERR(gpiod) == -ENOENT)
+       if (PTR_ERR(gpiod) == -ENOENT ||
+           PTR_ERR(gpiod) == -ENOSYS)
                gpiod = NULL;
        else if (IS_ERR(gpiod))
                return PTR_ERR(gpiod);

Totally untested...

	Andrew

quoted

 	/* Deassert the optional reset signal */
 	if (mdiodev->dev.of_node)
 		gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
 					       "reset-gpios", 0, GPIOD_OUT_LOW,
 					       "PHY reset");
-	if (PTR_ERR(gpiod) == -ENOENT ||
-	    PTR_ERR(gpiod) == -ENOSYS)
-		gpiod = NULL;
-	else if (IS_ERR(gpiod))
-		return PTR_ERR(gpiod);
+	if (IS_ERR(gpiod)) {
+		ret = PTR_ERR(gpiod);
+		if (ret == -ENOENT || ret == -ENOSYS)
+			gpiod = NULL;
+		else
+			return ret;
+	}
 
 	mdiodev->reset = gpiod;
 
-- 
2.7.4

Re: [PATCH net-next] mdio_bus: Fix PTR_ERR() usage after initialization to constant

From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2019-02-01 04:24:25

On Tue, Jan 29, 2019 at 11:30:27AM +0800, YueHaibing wrote:

quoted

 		gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
 					       "reset-gpios", 0, GPIOD_OUT_LOW,
 					       "PHY reset");
-	if (PTR_ERR(gpiod) == -ENOENT ||
-	    PTR_ERR(gpiod) == -ENOSYS)
-		gpiod = NULL;
-	else if (IS_ERR(gpiod))
-		return PTR_ERR(gpiod);
+	if (IS_ERR(gpiod)) {
+		ret = PTR_ERR(gpiod);
+		if (ret == -ENOENT || ret == -ENOSYS)
+			gpiod = NULL;
+		else
+			return ret;
+	}

Rule of the thumb: PTR_ERR(p) == -E... is almost always better off
as p == ERR_PTR(-E...)

Re: [PATCH net-next] mdio_bus: Fix PTR_ERR() usage after initialization to constant

From: YueHaibing <hidden>
Date: 2019-02-16 02:41:10

On 2019/2/1 12:24, Al Viro wrote:

On Tue, Jan 29, 2019 at 11:30:27AM +0800, YueHaibing wrote:

quoted

 		gpiod = fwnode_get_named_gpiod(&mdiodev->dev.of_node->fwnode,
 					       "reset-gpios", 0, GPIOD_OUT_LOW,
 					       "PHY reset");
-	if (PTR_ERR(gpiod) == -ENOENT ||
-	    PTR_ERR(gpiod) == -ENOSYS)
-		gpiod = NULL;
-	else if (IS_ERR(gpiod))
-		return PTR_ERR(gpiod);
+	if (IS_ERR(gpiod)) {
+		ret = PTR_ERR(gpiod);
+		if (ret == -ENOENT || ret == -ENOSYS)
+			gpiod = NULL;
+		else
+			return ret;
+	}

Rule of the thumb: PTR_ERR(p) == -E... is almost always better off
as p == ERR_PTR(-E...)

Ok, will fix it.

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