[PATCH] net: gianfar: fix reference counting for phy_node

[PATCH] net: gianfar: fix reference counting for phy_node

[Uwe Kleine-König]

The line before the changed if condition is:

	priv->phy_node = of_parse_phandle(np, "phy-handle", 0);

. If this call succeeds priv->phy_node must not be overwritten in the if
block; otherwise the reference to the node returned by of_parse_phandle
is lost. So add a check that the if block isn't executed in this case.

Furthermore in the fixed phy case no reference is aquired for phy_node
resulting in an of_node_put without holding a reference. To fix that,
get a reference on the MAC dt node.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/net/ethernet/freescale/gianfar.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 6b0c4775cd0d..adc7c718c4bc 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -897,7 +897,7 @@ static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 		if (err)
 			goto err_grp_init;
 
-		priv->phy_node = np;
+		priv->phy_node = of_node_get(np);
 	}
 
 	/* Find the TBI PHY.  If it's not there, we don't support SGMII */
-- 
2.0.1

[PATCH v2] net: gianfar: fix reference counting for phy_node

[Uwe Kleine-König]

The line before the changed if condition is:

	priv->phy_node = of_parse_phandle(np, "phy-handle", 0);

. If this call succeeds priv->phy_node must not be overwritten in the if
block; otherwise the reference to the node returned by of_parse_phandle
is lost. So add a check that the if block isn't executed in this case.

Furthermore in the fixed phy case no reference is aquired for phy_node
resulting in an of_node_put without holding a reference. To fix that,
get a reference on the MAC dt node.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
Changes since (implicit) v1:

 - really do both fixes mentioned in the commit log

 drivers/net/ethernet/freescale/gianfar.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 6b0c4775cd0d..fb29d049f4e1 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -892,12 +892,12 @@ static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 	/* In the case of a fixed PHY, the DT node associated
 	 * to the PHY is the Ethernet MAC DT node.
 	 */
-	if (of_phy_is_fixed_link(np)) {
+	if (!priv->phy_node && of_phy_is_fixed_link(np)) {
 		err = of_phy_register_fixed_link(np);
 		if (err)
 			goto err_grp_init;
 
-		priv->phy_node = np;
+		priv->phy_node = of_node_get(np);
 	}
 
 	/* Find the TBI PHY.  If it's not there, we don't support SGMII */
-- 
2.0.1

[PATCH v3] net: gianfar: fix reference counting for phy_node

[Uwe Kleine-König]

The line before the changed if condition is:

	priv->phy_node = of_parse_phandle(np, "phy-handle", 0);

. If this call succeeds priv->phy_node must not be overwritten in the if
block; otherwise the reference to the node returned by of_parse_phandle
is lost. So add a check that the if block isn't executed in this case.

Furthermore in the fixed phy case no reference is aquired for phy_node
resulting in an of_node_put without holding a reference. To fix that,
get a reference on the MAC dt node.

Fixes: be40364544bd ("gianfar: use the new fixed PHY helpers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
Changes since v2:

 - add a Fixes: footer as suggested by Thomas Petazzoni via irc

 drivers/net/ethernet/broadcom/genet/bcmmii.c          | 6 ++++--
 drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c | 2 +-
 drivers/net/ethernet/freescale/gianfar.c              | 4 ++--
 3 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c b/drivers/net/ethernet/broadcom/genet/bcmmii.c
index add8d8596084..693659f05776 100644
--- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
+++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
@@ -311,12 +311,12 @@ static int bcmgenet_mii_probe(struct net_device *dev)
 	/* In the case of a fixed PHY, the DT node associated
 	 * to the PHY is the Ethernet MAC DT node.
 	 */
-	if (of_phy_is_fixed_link(dn)) {
+	if (!priv->phy_dn && of_phy_is_fixed_link(dn)) {
 		ret = of_phy_register_fixed_link(dn);
 		if (ret)
 			return ret;
 
-		priv->phy_dn = dn;
+		priv->phy_dn = of_get_node(dn);
 	}
 
 	phydev = of_phy_connect(dev, priv->phy_dn, bcmgenet_mii_setup, 0,
@@ -452,6 +452,7 @@ int bcmgenet_mii_init(struct net_device *dev)
 	return 0;
 
 out:
+	of_node_put(priv->phy_dn);
 	mdiobus_unregister(priv->mii_bus);
 out_free:
 	kfree(priv->mii_bus->irq);
@@ -463,6 +464,7 @@ void bcmgenet_mii_exit(struct net_device *dev)
 {
 	struct bcmgenet_priv *priv = netdev_priv(dev);
 
+	of_node_put(priv->phy_dn);
 	mdiobus_unregister(priv->mii_bus);
 	kfree(priv->mii_bus->irq);
 	mdiobus_free(priv->mii_bus);
diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
index cfaf17b70f3f..748fd24d3d9e 100644
--- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
+++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
@@ -1033,7 +1033,7 @@ static int fs_enet_probe(struct platform_device *ofdev)
 		/* In the case of a fixed PHY, the DT node associated
 		 * to the PHY is the Ethernet MAC DT node.
 		 */
-		fpi->phy_node = ofdev->dev.of_node;
+		fpi->phy_node = of_node_get(ofdev->dev.of_node);
 	}
 
 	if (of_device_is_compatible(ofdev->dev.of_node, "fsl,mpc5125-fec")) {
diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 6b0c4775cd0d..fb29d049f4e1 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -892,12 +892,12 @@ static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 	/* In the case of a fixed PHY, the DT node associated
 	 * to the PHY is the Ethernet MAC DT node.
 	 */
-	if (of_phy_is_fixed_link(np)) {
+	if (!priv->phy_node && of_phy_is_fixed_link(np)) {
 		err = of_phy_register_fixed_link(np);
 		if (err)
 			goto err_grp_init;
 
-		priv->phy_node = np;
+		priv->phy_node = of_node_get(np);
 	}
 
 	/* Find the TBI PHY.  If it's not there, we don't support SGMII */
-- 
2.0.1

[PATCH v4] net: gianfar: fix reference counting for phy_node

[Uwe Kleine-König]

The line before the changed if condition is:

	priv->phy_node = of_parse_phandle(np, "phy-handle", 0);

. If this call succeeds priv->phy_node must not be overwritten in the if
block; otherwise the reference to the node returned by of_parse_phandle
is lost. So add a check that the if block isn't executed in this case.

Furthermore in the fixed phy case no reference is aquired for phy_node
resulting in an of_node_put without holding a reference. To fix that,
get a reference on the MAC dt node.

Fixes: be40364544bd ("gianfar: use the new fixed PHY helpers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
Hello,

I don't know how, but somehow I managed to add unrelated stuff to v3. So:

Changes since v3:

 - Reset patch to the v2 one.

Sorry for the patch flood, I hope I got it right this time.

Best regards
Uwe

 drivers/net/ethernet/freescale/gianfar.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c
index 6b0c4775cd0d..fb29d049f4e1 100644
--- a/drivers/net/ethernet/freescale/gianfar.c
+++ b/drivers/net/ethernet/freescale/gianfar.c
@@ -892,12 +892,12 @@ static int gfar_of_init(struct platform_device *ofdev, struct net_device **pdev)
 	/* In the case of a fixed PHY, the DT node associated
 	 * to the PHY is the Ethernet MAC DT node.
 	 */
-	if (of_phy_is_fixed_link(np)) {
+	if (!priv->phy_node && of_phy_is_fixed_link(np)) {
 		err = of_phy_register_fixed_link(np);
 		if (err)
 			goto err_grp_init;
 
-		priv->phy_node = np;
+		priv->phy_node = of_node_get(np);
 	}
 
 	/* Find the TBI PHY.  If it's not there, we don't support SGMII */
-- 
2.0.1

Re: [PATCH v4] net: gianfar: fix reference counting for phy_node

[David Miller]

From: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Date: Thu,  7 Aug 2014 22:17:07 +0200

> The line before the changed if condition is:
> 
> 	priv->phy_node = of_parse_phandle(np, "phy-handle", 0);
> 
> . If this call succeeds priv->phy_node must not be overwritten in the if
> block; otherwise the reference to the node returned by of_parse_phandle
> is lost. So add a check that the if block isn't executed in this case.
> 
> Furthermore in the fixed phy case no reference is aquired for phy_node
> resulting in an of_node_put without holding a reference. To fix that,
> get a reference on the MAC dt node.
> 
> Fixes: be40364544bd ("gianfar: use the new fixed PHY helpers")
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Applied.