net: phy: generate PHY mdio modalias

The modalias string provided in the uevent sysfs file does not conform
to the format used in PHY driver modules. One of the reasons is that
udev loading of PHY driver modules has not been an expected use case.

This patch changes the MODALIAS entry for only PHY devices from:
        MODALIAS=of:Nethernet-phyT(null)
to:
        MODALIAS=mdio:00000000001000100001010100010011

Other MDIO devices (such as DSA) remain as before.

However, having udev automatically load the module has the advantage
of making use of existing functionality to have the module loaded
before the device is bound to the driver, thus taking advantage of
multithreaded boot systems, potentially decreasing the boot time.

However, this patch will not solve any issues with the driver module
not being loaded prior to the network device needing to use the PHY.
This is something that is completely out of control of any patch to
change the uevent mechanism.

Reported-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/mdio.h b/include/linux/mdio.h
index 79ceee3c8673..08d091913808 100644
--- a/include/linux/mdio.h
+++ b/include/linux/mdio.h
@@ -32,6 +32,8 @@ struct mdio_device {
 	char modalias[MDIO_NAME_SIZE];
 
 	int (*bus_match)(struct device *dev, struct device_driver *drv);
+	int (*bus_uevent)(struct mdio_device *mdiodev,
+			  struct kobj_uevent_env *env);
 	void (*device_free)(struct mdio_device *mdiodev);
 	void (*device_remove)(struct mdio_device *mdiodev);