On Thu, Sep 10, 2020 at 03:58:49PM +0200, Hans de Goede wrote: > Hi, > > On 9/6/20 4:22 AM, Alan Stern wrote: > > 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. > > I agree that first trying to fix it is a good idea. > > > > 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. > > So I tried this: > > [root@localhost ~]# cat /sys/module/usbcore/parameters/initial_descriptor_timeout > 1000 > > But it does not really seem to help: > > [ 1171.435346] usb 1-3: USB disconnect, device number 2 > [ 1180.430958] usb 1-3: new full-speed USB device number 3 using xhci_hcd > [ 1180.551543] usb 1-3: device descriptor read/64, error -71 > [ 1184.045548] usb 1-3: device descriptor read/64, error -110 > [ 1184.270924] usb 1-3: new full-speed USB device number 4 using xhci_hcd > [ 1184.438336] usb 1-3: New USB device found, idVendor=06cb, idProduct=73f5, bcdDevice= 0.02 > [ 1184.438371] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0 > [ 1184.438399] usb 1-3: Product: ITE Device(8910) > [ 1184.438425] usb 1-3: Manufacturer: ITE Tech. Inc. That part of hub.c is a real mess. Coincidentally, I just posted a patch to try and fix it up a bit: https://marc.info/?l=linux-usb&m=159959185227447&w=2 If you apply that along with module parameter change, does it make any difference? (Or maybe you don't care to pursue this course and would prefer to work on the udev approach...) Alan Stern
