On Sat, Sep 05, 2020 at 01:37:38PM +0200, Hans de Goede wrote: > 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" My impression is that fixing this would be the simplest approach. Alan Stern > 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. Have you tried decreasing the initial_descriptor_timeout module parameter for usbcore? That would probably help, but it's kind of a sledgehammer. Alan Stern > Any input on this would be much appreciated. > > Regards, > > Hans
