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path: root/drivers/net/phy/phy_device.c
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Diffstat (limited to 'drivers/net/phy/phy_device.c')
-rw-r--r--drivers/net/phy/phy_device.c62
1 files changed, 48 insertions, 14 deletions
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index c0f211127274..f761288abe66 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -384,6 +384,24 @@ int phy_device_register(struct phy_device *phydev)
EXPORT_SYMBOL(phy_device_register);
/**
+ * phy_device_remove - Remove a previously registered phy device from the MDIO bus
+ * @phydev: phy_device structure to remove
+ *
+ * This doesn't free the phy_device itself, it merely reverses the effects
+ * of phy_device_register(). Use phy_device_free() to free the device
+ * after calling this function.
+ */
+void phy_device_remove(struct phy_device *phydev)
+{
+ struct mii_bus *bus = phydev->bus;
+ int addr = phydev->addr;
+
+ device_del(&phydev->dev);
+ bus->phy_map[addr] = NULL;
+}
+EXPORT_SYMBOL(phy_device_remove);
+
+/**
* phy_find_first - finds the first PHY device on the bus
* @bus: the target MII bus
*/
@@ -578,14 +596,22 @@ EXPORT_SYMBOL(phy_init_hw);
* generic driver is used. The phy_device is given a ptr to
* the attaching device, and given a callback for link status
* change. The phy_device is returned to the attaching driver.
+ * This function takes a reference on the phy device.
*/
int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
u32 flags, phy_interface_t interface)
{
+ struct mii_bus *bus = phydev->bus;
struct device *d = &phydev->dev;
- struct module *bus_module;
int err;
+ if (!try_module_get(bus->owner)) {
+ dev_err(&dev->dev, "failed to get the bus module\n");
+ return -EIO;
+ }
+
+ get_device(d);
+
/* Assume that if there is no driver, that it doesn't
* exist, and we should use the genphy driver.
*/
@@ -600,20 +626,13 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
err = device_bind_driver(d);
if (err)
- return err;
+ goto error;
}
if (phydev->attached_dev) {
dev_err(&dev->dev, "PHY already attached\n");
- return -EBUSY;
- }
-
- /* Increment the bus module reference count */
- bus_module = phydev->bus->dev.driver ?
- phydev->bus->dev.driver->owner : NULL;
- if (!try_module_get(bus_module)) {
- dev_err(&dev->dev, "failed to get the bus module\n");
- return -EIO;
+ err = -EBUSY;
+ goto error;
}
phydev->attached_dev = dev;
@@ -636,6 +655,11 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
phy_resume(phydev);
return err;
+
+error:
+ put_device(d);
+ module_put(bus->owner);
+ return err;
}
EXPORT_SYMBOL(phy_attach_direct);
@@ -677,14 +701,15 @@ EXPORT_SYMBOL(phy_attach);
/**
* phy_detach - detach a PHY device from its network device
* @phydev: target phy_device struct
+ *
+ * This detaches the phy device from its network device and the phy
+ * driver, and drops the reference count taken in phy_attach_direct().
*/
void phy_detach(struct phy_device *phydev)
{
+ struct mii_bus *bus;
int i;
- if (phydev->bus->dev.driver)
- module_put(phydev->bus->dev.driver->owner);
-
phydev->attached_dev->phydev = NULL;
phydev->attached_dev = NULL;
phy_suspend(phydev);
@@ -700,6 +725,15 @@ void phy_detach(struct phy_device *phydev)
break;
}
}
+
+ /*
+ * The phydev might go away on the put_device() below, so avoid
+ * a use-after-free bug by reading the underlying bus first.
+ */
+ bus = phydev->bus;
+
+ put_device(&phydev->dev);
+ module_put(bus->owner);
}
EXPORT_SYMBOL(phy_detach);