Hi,
On 9/10/20 5:41 PM, Alan Stern wrote:
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.
<snip>
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
Ok, I've applied the patch and tried again (with initial_descriptor_timeout still set to 1000),
so now the log from the reconnect looks look this:
[ 1157.248439] usb 1-3: new full-speed USB device number 3 using xhci_hcd
[ 1157.254234] usb 1-3: device descriptor read/64, error -71
[ 1157.371442] usb 1-3: new full-speed USB device number 4 using xhci_hcd
[ 1158.377895] usb 1-3: device descriptor read/64, error -110
[ 1158.379646] usb usb1-port3: attempt power cycle
[ 1159.014480] usb 1-3: new full-speed USB device number 5 using xhci_hcd
[ 1159.176112] usb 1-3: New USB device found, idVendor=06cb, idProduct=73f5, bcdDevice= 0.02
[ 1159.176138] usb 1-3: New USB device strings: Mfr=1, Product=2, SerialNumber=0
[ 1159.176156] usb 1-3: Product: ITE Device(8910)
[ 1159.176172] usb 1-3: Manufacturer: ITE Tech. Inc.
Still a bit slower then the old probe method, but much better then the
new probe method with the default initial_descriptor_timeout.
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...)
No, I would like to see this fixed properly in the kernel, but this is
somewhat low on my prioritry list, esp. during workdays, so that why I'm
a bit slow with responding, sorry.
Regards,
Hans
