Re: [PATCH] xhci: Fix HIK camera control timeout on Etron hosts

[Kuangyi Chiang]

Hi,

Mathias Nyman <mathias.nyman@xxxxxxxxxxxxxxx> 於 2026年9月16日週三 下午8:18寫道：
>
> On 9/16/26 04:33, Kuangyi Chiang wrote:
> > Hi,
> >
> > Thanks for the review.
> >
> > Michal Pecio <michal.pecio@xxxxxxxxx> 於 2026年9月14日週一 下午7:09寫道：
> >>
> >> On Mon, 14 Sep 2026 09:30:33 +0800, Kuangyi Chiang wrote:
> >>> Control transfers to the HIK 1080P Camera (2bdf:0280) can time out when
> >>> the device is connected through an Etron xHCI host:
> >>>
> >>> [   48.363671] uvcvideo: Found UVC 1.00 device HIK 1080P Camera (2bdf:0280)
> >>> [   53.465662] uvcvideo: Failed to set UVC probe control : -110 (exp. 26).
> >>> [   58.585653] uvcvideo: Failed to query (129) UVC probe control : -110 (exp. 26).
> >>> [   58.592967] uvcvideo: Failed to initialize the device (-5).
> >>>
> >>> Testing shows that at least 125 us between control transfers is required
> >>> to avoid the timeout. Limit the workaround to the affected Etron host and
> >>> USB device combination to avoid changing control-transfer timing for other
> >>> devices.
> >>
> >> Any idea why it happens or why the delay helps?
> >
> > We don't know the root cause yet, but we did some more testing.
> >
> > We tested delays of 50us, 125us, and 200us. The issue was still
> > reproducible with 50us, while 125us and 200us passed our test.
> >
> > Our pass criterion is 30 successful plug/unplug cycles on each port.
> > So 125us is the minimum delay we tested that consistently works.
> >
>
> Are there issues with the control transfers already during enumeration
> of the device, when reading descriptors etc, or are these issues only
> visible after uvc driver is controlling the device?
>
>
> > We also tried USB_QUIRK_DELAY_CTRL_MSG, but its 200ms delay is too
> > long and causes UVC initialization to fail.
> >
>
> Does it help if you as a hack set udev->quirks |= USB_QUIRK_DELAY_CTRL_MSG
> _after_ enumeration and uvc initialization?
>
> >> How many other HCs did you test this camera with?
> >
> > The camera works with the EHCI host we tested without any delay.
> > We can also reproduce a similar issue with an ASMedia ASM1142 xHCI
> > host (1b21:1242). This patch, however, is limited to the Etron/HIK
> > combination.
>
> I think we should avoid usb device specific quirks in the xhci driver,
> especially now that we know it's not really tied to a specific xHC vendor.
>
> If this is only an issue with the control transfers sent by uvc driver
> then I think this device specific quirk should be in there.
>

Thanks for the suggestions.

We'll do some more testing based on your suggestions, including
enabling USB_QUIRK_DELAY_CTRL_MSG after UVC initialization.

We'll report back once we have the results.

Thanks,
Kuangyi