On Sat, Oct 15, 2016 at 10:25:42PM +0300, Matwey V. Kornilov wrote:

[snip]

> >>> > Which means without this commit your camera has been working without
> >>> > issues, and this is a regression with this commit, right?
> >>> >
> >>>
> >>> Right
> >>
> >> Okay, thanks for confirming.
> >>
> >> But we cannot just simply add this flag, as it breaks many other use
> >> cases. I will continue work on this to find a solution which works on
> >> all use cases.
> >>
> >
> > Ok, thank you.
> >
> 
> Excuse me. Any news?

Not solved yet. I used uvc class to exam the issue. uvc_video driver
takes longer time to execute urb complete() on my platform. Using HCD_BH
flag doesn't help, because urb->complete() was running with irq disabled
because of the local_irq. Removing the local_irq as in [1] causes the
system to lockup - uart and network stop responsing, so hard to debug
for now.

Right now, I added a workqueue in musb_host to handle urb->complete()
with local_irq removed. It seems working fine in my test, but it is
still a long way find the proper fix for upstream. I didn't have much
time on this issue.

Once I have a proper solution, I will post it to the mailing list.

[1] http://marc.info/?l=linux-usb&m=147560701431267&w=2

Regards,
-Bin.
--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to