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>
diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index 35d753d..74a8232 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -575,6 +575,7 @@
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 @@
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 @@
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);