@@ -666,8 +666,9 @@ static int asix_resume(struct usb_interface *intf)
static int ax88772_init_mdio(struct usbnet *dev)
{
struct asix_common_private *priv = dev->driver_priv;
+ int ret;
- priv->mdio = devm_mdiobus_alloc(&dev->udev->dev);
+ priv->mdio = mdiobus_alloc();
if (!priv->mdio)
return -ENOMEM;
@@ -679,7 +680,20 @@ static int ax88772_init_mdio(struct usbnet *dev)
snprintf(priv->mdio->id, MII_BUS_ID_SIZE, "usb-%03d:%03d",
dev->udev->bus->busnum, dev->udev->devnum);
- return devm_mdiobus_register(&dev->udev->dev, priv->mdio);
+ ret = mdiobus_register(priv->mdio);
+ if (ret) {
+ netdev_err(dev->net, "Could not register MDIO bus (err %d)\n", ret);
+ mdiobus_free(priv->mdio);
+ priv->mdio = NULL;
+ }
+
+ return ret;
+}
+
+static void ax88772_mdio_unregister(struct asix_common_private *priv)
+{
+ mdiobus_unregister(priv->mdio);
+ mdiobus_free(priv->mdio);
}
static int ax88772_init_phy(struct usbnet *dev)
@@ -896,16 +910,23 @@ static int ax88772_bind(struct usbnet *dev, struct usb_interface *intf)
ret = ax88772_init_mdio(dev);
if (ret)
- return ret;
+ goto mdio_err;
ret = ax88772_phylink_setup(dev);
if (ret)
- return ret;
+ goto phylink_err;
ret = ax88772_init_phy(dev);
if (ret)
- phylink_destroy(priv->phylink);
+ goto initphy_err;
+ return 0;
+
+initphy_err:
+ phylink_destroy(priv->phylink);
+phylink_err:
+ ax88772_mdio_unregister(priv);
+mdio_err:
return ret;
}
@@ -926,6 +947,7 @@ static void ax88772_unbind(struct usbnet *dev, struct usb_interface *intf)
phylink_disconnect_phy(priv->phylink);
rtnl_unlock();
phylink_destroy(priv->phylink);
+ ax88772_mdio_unregister(priv);
asix_rx_fixup_common_free(dev->driver_priv);
}
"modprobe asix ; rmmod asix ; modprobe asix" fails with: sysfs: cannot create duplicate filename \ '/devices/virtual/mdio_bus/usb-003:004' Issue was originally reported by Anton Lundin on 2022-06-22 (link below). Chrome OS team hit the same issue in Feb, 2023 when trying to find work arounds for other issues with AX88172 devices. The use of devm_mdiobus_register() with usbnet devices results in the MDIO data being associated with the USB device. When the asix driver is unloaded, the USB device continues to exist and the corresponding "mdiobus_unregister()" is NOT called until the USB device is unplugged or unauthorized. So the next "modprobe asix" will fail because the MDIO phy sysfs attributes still exist. The 'easy' (from a design PoV) fix is to use the non-devm variants of mdiobus_* functions and explicitly manage this use in the asix_bind and asix_unbind function calls. I've not explored trying to fix usbnet initialization so devm_* stuff will work. Fixes: e532a096be0e5 ("net: usb: asix: ax88772: add phylib support") Reported-by: Anton Lundin <glance@acc.umu.se> Link: https://lore.kernel.org/netdev/20220623063649.GD23685@pengutronix.de/T/ Tested-by: Eizan Miyamoto <eizan@chromium.org> Signed-off-by: Grant Grundler <grundler@chromium.org> --- drivers/net/usb/asix_devices.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) V6: overlooked format-path "1/2" when generating this patch. V5: remove ax88772_mdio_unregister() call from error path in ax88772_init_phy() Jakub pointed out ax88772_mdio_unregister() will get called twice. (note: putting mdio handling in one function helps avoid this kind of bug.) V4: add mdio_unregister to ax88172_bind() error handling paths V3: rebase against netdev/net.git remove "TEST" prefix in subject line added Link: tag for Reported-by tag V2: moved mdiobus_get_phy() call back into ax88772_init_phy() (Lukas Wunner is entirely correct this patch is much easier to backport without this patch hunk.) Added "Fixes:" tag per request from Florian Fainelli