Hi On 12.2.2021 0.11, Yiyu Zhu wrote: > I was trying to unplug the hub manually so that I can trigger this > issue. The kworker only shows up when the hub is actually > disconnected. They will be gone if any thing is connected back into > the port. > > The hub works normally when it is connected. And no additional dmesg is printed. Could you add usbcore dynamic debug, it should show more details about hub activity. mount -t debugfs none /sys/kernel/debug echo 'module usbcore =p' >/sys/kernel/debug/dynamic_debug/control >>> [ 2798.677498] usb usb3-port2: over-current condition hub reports overcurrent condition, worth keeping in mind. >>> [ 2799.209385] usb 4-2: USB disconnect, device number 2 >>> [ 2799.209392] usb 4-2.1: USB disconnect, device number 3 >>> [ 2799.209396] usb 4-2.1.3: USB disconnect, device number 4 >>> [ 2799.302548] usb 4-2.1.4: USB disconnect, device number 5 >>> [ 2799.633505] usb 4-2.1-port4: cannot disable (err = -110) >>> [ 2800.181325] usb usb4-port2: over-current condition >>> [ 2818.993944] xhci_hcd 0000:38:00.0: xHCI host controller not >>> responding, assume dead >>> [ 2818.993956] xhci_hcd 0000:38:00.0: HC died; cleaning up >>> [ 2819.126421] xhci_hcd 0000:38:00.0: remove, state 1 >>> [ 2819.126431] usb usb4: USB disconnect, device number 1 >>> [ 2819.154189] xhci_hcd 0000:38:00.0: USB bus 4 deregistered >>> [ 2819.154206] xhci_hcd 0000:38:00.0: remove, state 1 >>> [ 2819.154211] usb usb3: USB disconnect, device number 1 >>> [ 2819.154684] xhci_hcd 0000:38:00.0: Host halt failed, -19 >>> [ 2819.154689] xhci_hcd 0000:38:00.0: Host not accessible, reset failed. >>> [ 2819.154900] xhci_hcd 0000:38:00.0: USB bus 3 deregistered >>> [ 2819.156059] pcieport 0000:03:00.0: can't change power state from >>> D3cold to D0 (config space inaccessible) >>> [ 2819.156709] pci_bus 0000:04: busn_res: [bus 04] is released >>> [ 2819.156776] pci_bus 0000:05: busn_res: [bus 05-37] is released >>> [ 2819.169419] pci_bus 0000:38: busn_res: [bus 38] is released >>> [ 2819.169491] pci_bus 0000:39: busn_res: [bus 39-6c] is released >>> [ 2819.169533] pci_bus 0000:03: busn_res: [bus 03-6c] is released Is this xHC contoller in a Alpine Ridge/Titan Ridge/Maple Ridge based system that has runtime PM enabled by default, and whole xHC controller disappears from PCI bus when last device is disconnected? (check with lspci -nn) Does it help if another USB device is connected to a different roothub port of this xHC while disconnecting the hub? Or does just disabling runtime PM for this xhci help? Thanks Mathias
