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authorRussell King <rmk+kernel@arm.linux.org.uk>2015-09-24 20:36:13 +0100
committerDavid S. Miller <davem@davemloft.net>2015-09-24 23:04:52 -0700
commitf018ae7a8c576345d56a0cd40d86c0574a2eb360 (patch)
tree71e460c11f9dead62f31503e1608c21cefbe0a50 /drivers/of/of_mdio.c
parent7322967bc1bd97ac9c49ecea19e5a1f681ca27ee (diff)
downloadlinux-f018ae7a8c576345d56a0cd40d86c0574a2eb360.tar.bz2
of_mdio: fix MDIO phy device refcounting
bus_find_device() is defined as: * This is similar to the bus_for_each_dev() function above, but it * returns a reference to a device that is 'found' for later use, as * determined by the @match callback. and it does indeed return a reference-counted pointer to the device: while ((dev = next_device(&i))) if (match(dev, data) && get_device(dev)) ^^^^^^^^^^^^^^^ break; klist_iter_exit(&i); return dev; What that means is that when we're done with the struct device, we must drop that reference. Neither of_phy_connect() nor of_phy_attach() did this when phy_connect_direct() or phy_attach_direct() failed. With our previous patch, phy_connect_direct() and phy_attach_direct() take a new refcount on the phy device when successful, so we can drop our local reference immediatley after these functions, whether or not they succeeded. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/of/of_mdio.c')
-rw-r--r--drivers/of/of_mdio.c27
1 files changed, 23 insertions, 4 deletions
diff --git a/drivers/of/of_mdio.c b/drivers/of/of_mdio.c
index 1350fa25cdb0..a87a868fed64 100644
--- a/drivers/of/of_mdio.c
+++ b/drivers/of/of_mdio.c
@@ -197,7 +197,8 @@ static int of_phy_match(struct device *dev, void *phy_np)
* of_phy_find_device - Give a PHY node, find the phy_device
* @phy_np: Pointer to the phy's device tree node
*
- * Returns a pointer to the phy_device.
+ * If successful, returns a pointer to the phy_device with the embedded
+ * struct device refcount incremented by one, or NULL on failure.
*/
struct phy_device *of_phy_find_device(struct device_node *phy_np)
{
@@ -217,7 +218,9 @@ EXPORT_SYMBOL(of_phy_find_device);
* @hndlr: Link state callback for the network device
* @iface: PHY data interface type
*
- * Returns a pointer to the phy_device if successful. NULL otherwise
+ * If successful, returns a pointer to the phy_device with the embedded
+ * struct device refcount incremented by one, or NULL on failure. The
+ * refcount must be dropped by calling phy_disconnect() or phy_detach().
*/
struct phy_device *of_phy_connect(struct net_device *dev,
struct device_node *phy_np,
@@ -225,13 +228,19 @@ struct phy_device *of_phy_connect(struct net_device *dev,
phy_interface_t iface)
{
struct phy_device *phy = of_phy_find_device(phy_np);
+ int ret;
if (!phy)
return NULL;
phy->dev_flags = flags;
- return phy_connect_direct(dev, phy, hndlr, iface) ? NULL : phy;
+ ret = phy_connect_direct(dev, phy, hndlr, iface);
+
+ /* refcount is held by phy_connect_direct() on success */
+ put_device(&phy->dev);
+
+ return ret ? NULL : phy;
}
EXPORT_SYMBOL(of_phy_connect);
@@ -241,17 +250,27 @@ EXPORT_SYMBOL(of_phy_connect);
* @phy_np: Node pointer for the PHY
* @flags: flags to pass to the PHY
* @iface: PHY data interface type
+ *
+ * If successful, returns a pointer to the phy_device with the embedded
+ * struct device refcount incremented by one, or NULL on failure. The
+ * refcount must be dropped by calling phy_disconnect() or phy_detach().
*/
struct phy_device *of_phy_attach(struct net_device *dev,
struct device_node *phy_np, u32 flags,
phy_interface_t iface)
{
struct phy_device *phy = of_phy_find_device(phy_np);
+ int ret;
if (!phy)
return NULL;
- return phy_attach_direct(dev, phy, flags, iface) ? NULL : phy;
+ ret = phy_attach_direct(dev, phy, flags, iface);
+
+ /* refcount is held by phy_attach_direct() on success */
+ put_device(&phy->dev);
+
+ return ret ? NULL : phy;
}
EXPORT_SYMBOL(of_phy_attach);