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

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

[Kuangyi Chiang]

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.

Perform the delay before taking xhci->lock so the existing state validation
and TD queueing remain in the same critical section. Use udelay() because
urb_enqueue() may be called from atomic context and cannot use a sleeping
delay.

Signed-off-by: Kuangyi Chiang <ki.chiang65@gmail.com>
---
 drivers/usb/host/xhci.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 5c759ad..925716a 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1648,6 +1648,16 @@ static int xhci_urb_enqueue(struct usb_hcd *hcd, struct urb *urb, gfp_t mem_flag
 
 	trace_xhci_urb_enqueue(urb);
 
+	/*
+	 * This camera needs at least 125 us between control transfers
+	 * when used with an Etron xHCI host.
+	 */
+	if ((xhci->quirks & XHCI_ETRON_HOST) &&
+	    usb_endpoint_xfer_control(&urb->ep->desc) &&
+	    le16_to_cpu(urb->dev->descriptor.idVendor) == 0x2bdf &&
+	    le16_to_cpu(urb->dev->descriptor.idProduct) == 0x0280)
+		udelay(125);
+
 	spin_lock_irqsave(&xhci->lock, flags);
 
 	ret = xhci_check_args(hcd, urb->dev, urb->ep,
-- 
2.25.1

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

[Michal Pecio]

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?
How many other HCs did you test this camera with?
Does it help to reconnect and try again?

FWIW, I tried a few USB 2.0 cameras with my Etron and they mostly work,
except one. It passes probe just fine, but fails on streaming attempt.
Adding 125us delay doesn't help, but 1000 works sometimes and 4000 even
more often.

Probably a HW bug. Honestly, I never use Etron for anything serious.

> Perform the delay before taking xhci->lock so the existing state
> validation and TD queueing remain in the same critical section. Use
> udelay() because urb_enqueue() may be called from atomic context and
> cannot use a sleeping delay.

Actually, you would need to do that under lock if you want to ensure
that multiple callers can't submit URBs closely together. But that's
dodgy and we don't even know what exactly triggers it or whether this
solution really is the best one.

Regards,
Michal

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

[Kuangyi Chiang]

Hi,

Thanks for the review.

Michal Pecio <michal.pecio@gmail.com> 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.

We also tried USB_QUIRK_DELAY_CTRL_MSG, but its 200ms delay is too
long and causes UVC initialization to fail.

> 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.

> Does it help to reconnect and try again?

No. The issue is still reproducible after reconnecting the camera.

>
> FWIW, I tried a few USB 2.0 cameras with my Etron and they mostly work,
> except one. It passes probe just fine, but fails on streaming attempt.
> Adding 125us delay doesn't help, but 1000 works sometimes and 4000 even
> more often.
>
> Probably a HW bug. Honestly, I never use Etron for anything serious.
>
> > Perform the delay before taking xhci->lock so the existing state
> > validation and TD queueing remain in the same critical section. Use
> > udelay() because urb_enqueue() may be called from atomic context and
> > cannot use a sleeping delay.
>
> Actually, you would need to do that under lock if you want to ensure
> that multiple callers can't submit URBs closely together. But that's
> dodgy and we don't even know what exactly triggers it or whether this
> solution really is the best one.

Agreed. For the UVC control transfers involved here, the next transfer
is submitted only after the previous one completes, so they are
serialized.

The delay before xhci->lock does not prevent other callers from
submitting control URBs close together. However, this workaround is
limited to control transfers for the affected Etron/HIK combination.

Regards,
Kuangyi

>
> Regards,
> Michal

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

[Mathias Nyman]

On 9/16/26 04:33, Kuangyi Chiang wrote:
> Hi,
> 
> Thanks for the review.
> 
> Michal Pecio <michal.pecio@gmail.com> 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
Mathias

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

[Kuangyi Chiang]

Hi,

Mathias Nyman <mathias.nyman@linux.intel.com> 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@gmail.com> 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

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

[Kuangyi Chiang]

Hi,

Sorry for the late reply.

Kuangyi Chiang <ki.chiang65@gmail.com> 於 2026年9月18日週五 上午9:58寫道：
>
> Hi,
>
> Mathias Nyman <mathias.nyman@linux.intel.com> 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@gmail.com> 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.

We did some more testing.

We don't see this issue during device enumeration.

We also found that the timeout is not limited to UVC control
transfers. In one failure case, the first timeout was observed in
a UAC control transfer, followed by UVC control transfer timeouts:

[  961.127402] usb 2-3: 5:2: failed to get current value for ch 0 (-110)
[  971.367443] uvcvideo 2-3:1.0: Failed to query (GET_DEF) UVC control
2 on unit 2: -110 (exp. 2).
[  976.487473] uvcvideo 2-3:1.0: Failed to query (GET_DEF) UVC control
3 on unit 2: -110 (exp. 2).

As suggested, we also tried enabling USB_QUIRK_DELAY_CTRL_MSG after
UVC initialization, but subsequent UVC control transfers still timed
out. In addition, UAC control transfers may already have timed out
before the quirk is enabled.

So far, we have reproduced the issue with these xHCI hosts:

ASMedia ASM1142 (1b21:1242)
Etron EJ168 (1b6f:7023)
Etron EJ188 (1b6f:7052)
Intel xHCI (8086:8d31)

The issue is less frequently reproducible on the ASMedia host.

The camera works with the EHCI host we tested without any additional
delay.

So we agree that this device-specific workaround should not be in the
xHCI driver. Since the issue can affect both UAC and UVC control
transfers, we plan to handle it in the corresponding class drivers.

Thanks,
Kuangyi

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

[Michal Pecio]

On Thu, 29 Oct 2026 10:25:17 +0800, Kuangyi Chiang wrote:
> We did some more testing.
> 
> We don't see this issue during device enumeration.
> 
> We also found that the timeout is not limited to UVC control
> transfers. In one failure case, the first timeout was observed in
> a UAC control transfer, followed by UVC control transfer timeouts:
> 
> [  961.127402] usb 2-3: 5:2: failed to get current value for ch 0 (-110)
> [  971.367443] uvcvideo 2-3:1.0: Failed to query (GET_DEF) UVC control
> 2 on unit 2: -110 (exp. 2).
> [  976.487473] uvcvideo 2-3:1.0: Failed to query (GET_DEF) UVC control
> 3 on unit 2: -110 (exp. 2).

But that's the same device and the same control pipe, right?

So it just failed and we don't know why or whether it was the host or
the device. And this is all during UVC/UAC probe, before any userspace
begins using the device? Or could userspace be involved?

The UVC driver has some aggressive PM; for every userspace ioctl, it
calls usb_autopm_get_interface(), submits an interrupt URB which almost
never completes and unlinks the URB before usb_autopm_put_interface().
Repeated periodic unlinks is a known problem case for many xHCI chips.

FYI, I found that 7c0c31c66a7f9 in v7.3 reduced occurrences of periodic
unlink failures on other junk HW like ASMedia and VIA. Some of those
failures, on ASMedia, resulted in control transfer breakage too.

Have you tried 7.3 yet?
Do you see any interrupt URBs there, using usbmon for example?

> So far, we have reproduced the issue with these xHCI hosts:
> 
> ASMedia ASM1142 (1b21:1242)
> Etron EJ168 (1b6f:7023)
> Etron EJ188 (1b6f:7052)
> Intel xHCI (8086:8d31)

I don't know that Intel chip, but the others are quite buggy.

Have you tried other HCs? Any successes?
IME, chips from NEC, Fresco, Renesas are more reliable.

> The camera works with the EHCI host we tested without any additional
> delay.

That's a little suspicious, it may still be an xHCI bug.

Regards,
Michal