Re: How to set USB_PORT_QUIRK_OLD_SCHEME on an usb-port ?

[Hans de Goede <hdegoede@redhat.com>]

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