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From: Bin Liu <b-liu@ti.com>
To: "Matwey V. Kornilov" <matwey@sai.msu.ru>
Cc: Alan Stern <stern@rowland.harvard.edu>, <hdegoede@redhat.com>,
	<linux-media@vger.kernel.org>, <linux-usb@vger.kernel.org>
Subject: Re: musb: isoc pkt loss with pwc
Date: Tue, 1 Nov 2016 15:33:46 -0500	[thread overview]
Message-ID: <20161101203346.GE30087@uda0271908> (raw)
In-Reply-To: <CAJs94EZXjETQGj44hphs61g9W1r-o9vJc+yy+9CeaxBy7Sa0Tg@mail.gmail.com>

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.

  reply	other threads:[~2016-11-01 20:34 UTC|newest]

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-08-28 10:13 musb: isoc pkt loss with pwc Matwey V. Kornilov
2016-08-30 18:30 ` Bin Liu
2016-08-30 20:44   ` Matwey V. Kornilov
2016-09-12  3:28     ` Bin Liu
2016-09-12  8:52       ` Matwey V. Kornilov
2016-09-12 18:57         ` Bin Liu
2016-09-12 19:38           ` Matwey V. Kornilov
2016-10-15 19:25             ` Matwey V. Kornilov
2016-11-01 20:33               ` Bin Liu [this message]
2017-01-27 17:13                 ` Matwey V. Kornilov
2017-04-15 14:58 ` Matwey V. Kornilov

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