phylib: Support phy module autoloading

We don't use the normal hotplug mechanism because it doesn't work. It will
load the module some time after the device appears, but that's not good
enough for us -- we need the driver loaded _immediately_ because otherwise
the NIC driver may just abort and then the phy 'device' goes away.

[bwh: s/phy/mdio/ in module alias, kerneldoc for struct mdio_device_id]

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 12 insertions, 0 deletions

diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c
index db1794546c56..1a99bb244106 100644
--- a/drivers/net/phy/phy_device.c
+++ b/drivers/net/phy/phy_device.c
@@ -149,6 +149,7 @@ EXPORT_SYMBOL(phy_scan_fixups);
 struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id)
 {
         struct phy_device *dev;
+
         /* We allocate the device, and initialize the
          * default values */
         dev = kzalloc(sizeof(*dev), GFP_KERNEL);
@@ -179,6 +180,17 @@ struct phy_device* phy_device_create(struct mii_bus *bus, int addr, int phy_id)
         mutex_init(&dev->lock);
         INIT_DELAYED_WORK(&dev->state_queue, phy_state_machine);
 
+        /* Request the appropriate module unconditionally; don't
+           bother trying to do so only if it isn't already loaded,
+           because that gets complicated. A hotplug event would have
+           done an unconditional modprobe anyway.
+           We don't do normal hotplug because it won't work for MDIO
+           -- because it relies on the device staying around for long
+           enough for the driver to get loaded. With MDIO, the NIC
+           driver will get bored and give up as soon as it finds that
+           there's no driver _already_ loaded. */
+        request_module(MDIO_MODULE_PREFIX MDIO_ID_FMT, MDIO_ID_ARGS(phy_id));
+
         return dev;
 }
 EXPORT_SYMBOL(phy_device_create);