Hi All, I have been debugging an issue with a 2-in-1 which consists of a tablet + a kbd-dock, where the device turns into a clamshell when docked into the kbd-dock. The kbd dock is connected via pogo-pins. This works fine when docked at boot. But there is an enumeration issue when hot-docked (and the keyboard looses power when the lid is closedm so this also triggers after a suspend/resume): [ 3498.924190] usb 1-3: new full-speed USB device number 5 using xhci_hcd [ 3499.041725] usb 1-3: device descriptor read/64, error -71 [ 3515.215890] usb 1-3: device descriptor read/64, error -110 [ 3515.440369] usb 1-3: new full-speed USB device number 6 using xhci_hcd [ 3515.603544] usb 1-3: New USB device found, idVendor=06cb, idProduct=73f5, bcdDevice= 0.02 [ 3515.603574] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 3515.603596] usb 1-3: Product: ITE Device(8910) [ 3515.603614] usb 1-3: Manufacturer: ITE Tech. Inc. Note there is about 6 seconds before the keyboard becomes usable, which is quite long when trying to unlock the laptop after opening the lid. If I set the USB_PORT_QUIRK_OLD_SCHEME on the port used by the kbd-dock: echo 1 > /sys/devices/pci0000\:00/0000\:00\:14.0/usb1/1-0\:1.0/usb1-port3/quirks Then this changes to: [ 4467.875008] usb 1-3: new full-speed USB device number 7 using xhci_hcd [ 4467.878483] usb 1-3: Device not responding to setup address. [ 4468.082476] usb 1-3: Device not responding to setup address. [ 4468.289990] usb 1-3: device not accepting address 7, error -71 [ 4468.614928] usb 1-3: new full-speed USB device number 8 using xhci_hcd [ 4468.662392] usb 1-3: New USB device found, idVendor=06cb, idProduct=73f5, bcdDevice= 0.02 [ 4468.662423] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [ 4468.662444] usb 1-3: Product: ITE Device(8910) [ 4468.662461] usb 1-3: Manufacturer: ITE Tech. Inc. Which is a lot better wrt making the keyboard available for use in a timely manner. So now I'm looking into a way to automatically do this. I would prefer to keep the handling of this out of the kernel, so I looked into udev, but it seems that the usb_port_device_type device-s registered by usb_hub_create_port_device() are not visible to udev? At least I'm not seeing them, in the output of "udevadm info -e" Note another option would be to set the global old_scheme_first kernel cmdline parameter on this 2-in-1. That can be done with a simple dmi_system_id table on which to do this, but adding such a table seems undesirable. A third option I guess would be to try and improve the probe time of the kbd-dock under the new scheme. Any input on this would be much appreciated. Regards, Hans
