On Fri, Mar 04, 2022 at 10:58:47AM -0300, Fabio Estevam wrote: > Hi Martyn, > > On Thu, Mar 3, 2022 at 10:14 AM Fabio Estevam <festevam@xxxxxxxxx> wrote: > > > > Hi, > > > > On a imx8mm-iotgateway board running kernel 5.17-rc6 I am getting the following > > smsc95xx errors after a 'reboot' command: > > > > ci_hdrc ci_hdrc.1: remove, state 1 > > usb usb2: USB disconnect, device number 1 > > usb 2-1: USB disconnect, device number 2 > > usb 2-1.1: USB disconnect, device number 3 > > smsc95xx 2-1.1:1.0 eth1: unregister 'smsc95xx' usb-ci_hdrc.1-1.1, > > smsc95xx USB 2.0 Ethernet > > smsc95xx 2-1.1:1.0 eth1: Failed to read reg index 0x00000114: -19 > > smsc95xx 2-1.1:1.0 eth1: Error reading MII_ACCESS > > smsc95xx 2-1.1:1.0 eth1: __smsc95xx_mdio_read: MII is busy > > smsc95xx 2-1.1:1.0 eth1: Failed to read reg index 0x00000114: -19 > > smsc95xx 2-1.1:1.0 eth1: Error reading MII_ACCESS > > smsc95xx 2-1.1:1.0 eth1: __smsc95xx_mdio_read: MII is busy > > smsc95xx 2-1.1:1.0 eth1: hardware isn't capable of remote wakeup > > The same error has been previously reported by Ferry Toth on Intel > Edison-Arduino: > https://lore.kernel.org/netdev/5cd6fc87-0f8d-0b9b-42be-8180540a94e7@xxxxxxxxx/ > > It happens after commit a049a30fc27c ("net: usb: Correct PHY handling > of smsc95xx") > > A simple way to reproduce it: > > echo -n "2-1" > /sys/bus/usb/drivers/usb/unbind > > It is not clear to me why register 0x114 (MII_ADDR) is accessed after > smsc95xx unregistration. I suggest you look at the call sequences. When does phy_stop() and phy_disconnect() get called? phylib has a work queue which runs once per second to poll the PHY and get its status. That polling is stopped by calling phy_stop(). It is also assumed you can still talk to the PHY while performing phy_stop(). Andrew
