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authorEzequiel Garcia <ezequiel.garcia@free-electrons.com>2014-07-23 16:47:32 -0300
committerDavid S. Miller <davem@davemloft.net>2014-07-24 18:09:52 -0700
commitb3565f278a9babc00032292be489e7fbff4f48d1 (patch)
tree79f99cf6c55a5c9fc663357008f7e3b9b873cf8d
parenta71e3c37960ce5f9c6a519bc1215e3ba9fa83e75 (diff)
downloadlinux-b3565f278a9babc00032292be489e7fbff4f48d1.tar.gz
net: phy: Ensure the MDIO bus module is held
This commit adds proper module_{get,put} to prevent the MDIO bus module from being unloaded while the phydev is connected. By doing so, we fix a kernel panic produced when a MDIO driver is removed, but the phydev that relies on it is attached and running. Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com> Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--drivers/net/phy/phy_device.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 35d753d22f7..74a82328dd4 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -575,6 +575,7 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
u32 flags, phy_interface_t interface)
{
struct device *d = &phydev->dev;
+ struct module *bus_module;
int err;
/* Assume that if there is no driver, that it doesn't
@@ -599,6 +600,14 @@ int phy_attach_direct(struct net_device *dev, struct phy_device *phydev,
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;
+ }
+
phydev->attached_dev = dev;
dev->phydev = phydev;
@@ -664,6 +673,10 @@ EXPORT_SYMBOL(phy_attach);
void phy_detach(struct phy_device *phydev)
{
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);