| Message ID | 20230314055410.3329480-1-grundler@chromium.org (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [PATCHv4,net] net: asix: fix modprobe "sysfs: cannot create duplicate filename" | expand |
On Mon, Mar 13, 2023 at 10:54:10PM -0700, Grant Grundler wrote: > "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 | 33 ++++++++++++++++++++++++++++----- > 1 file changed, 28 insertions(+), 5 deletions(-) > > 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 > > diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c > index 743cbf5d662c..b758010bab36 100644 > --- a/drivers/net/usb/asix_devices.c > +++ b/drivers/net/usb/asix_devices.c > @@ -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); Hi, Patch looks good, one question, are the devm_mdiobus_alloc() and devm_mdiobus_register functions used anywhere after removing? Maybe it is worth to remove also the implementation if it isn't used. Otherwise Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com> > + 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) > @@ -690,6 +704,7 @@ static int ax88772_init_phy(struct usbnet *dev) > priv->phydev = mdiobus_get_phy(priv->mdio, priv->phy_addr); > if (!priv->phydev) { > netdev_err(dev->net, "Could not find PHY\n"); > + ax88772_mdio_unregister(priv); > return -ENODEV; > } > > @@ -896,16 +911,23 @@ 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 +948,7 @@ 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); > } > > -- > 2.40.0.rc1.284.g88254d51c5-goog >
On Mon, 13 Mar 2023 22:54:10 -0700 Grant Grundler wrote: > @@ -690,6 +704,7 @@ static int ax88772_init_phy(struct usbnet *dev) > priv->phydev = mdiobus_get_phy(priv->mdio, priv->phy_addr); > if (!priv->phydev) { > netdev_err(dev->net, "Could not find PHY\n"); > + ax88772_mdio_unregister(priv); this line needs to go now.. > return -ENODEV; .. since if we return error here .. > } > > @@ -896,16 +911,23 @@ 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); .. it will pop out here .. > if (ret) > - phylink_destroy(priv->phylink); > + goto initphy_err; > > + return 0; > + > +initphy_err: > + phylink_destroy(priv->phylink); > +phylink_err: > + ax88772_mdio_unregister(priv); .. and then call ax88772_mdio_unregister() a second time. > +mdio_err: > return ret; > }
On Wed, Mar 15, 2023 at 10:08 PM Jakub Kicinski <kuba@kernel.org> wrote: > > On Mon, 13 Mar 2023 22:54:10 -0700 Grant Grundler wrote: > > @@ -690,6 +704,7 @@ static int ax88772_init_phy(struct usbnet *dev) > > priv->phydev = mdiobus_get_phy(priv->mdio, priv->phy_addr); > > if (!priv->phydev) { > > netdev_err(dev->net, "Could not find PHY\n"); > > + ax88772_mdio_unregister(priv); > > this line needs to go now.. > > > return -ENODEV; > > .. since if we return error here .. > > > } > > > > @@ -896,16 +911,23 @@ 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); > > .. it will pop out here .. > > > if (ret) > > - phylink_destroy(priv->phylink); > > + goto initphy_err; > > > > + return 0; > > + > > +initphy_err: > > + phylink_destroy(priv->phylink); > > +phylink_err: > > + ax88772_mdio_unregister(priv); > > .. and then call ax88772_mdio_unregister() a second time. Doh! Yes - good catch. Let me fix that. cheers, grant > > > +mdio_err: > > return ret; > > }
diff --git a/drivers/net/usb/asix_devices.c b/drivers/net/usb/asix_devices.c index 743cbf5d662c..b758010bab36 100644 --- a/drivers/net/usb/asix_devices.c +++ b/drivers/net/usb/asix_devices.c @@ -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) @@ -690,6 +704,7 @@ static int ax88772_init_phy(struct usbnet *dev) priv->phydev = mdiobus_get_phy(priv->mdio, priv->phy_addr); if (!priv->phydev) { netdev_err(dev->net, "Could not find PHY\n"); + ax88772_mdio_unregister(priv); return -ENODEV; } @@ -896,16 +911,23 @@ 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 +948,7 @@ 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 | 33 ++++++++++++++++++++++++++++----- 1 file changed, 28 insertions(+), 5 deletions(-) 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