Re: snd-usb: "delay: estimated 0, actual 352"

From: Markus Trippelsdorf
Date: Thu Sep 06 2012 - 09:17:58 EST


On 2012.09.06 at 15:08 +0200, Takashi Iwai wrote:
> At Thu, 6 Sep 2012 11:43:48 +0200,
> Markus Trippelsdorf wrote:
> >
> > On 2012.09.06 at 10:21 +0200, Takashi Iwai wrote:
> > > At Thu, 06 Sep 2012 09:35:26 +0200,
> > > Takashi Iwai wrote:
> > >
> > > In short, a patch like below may fix the issue (note: completely
> > > untested!)
> >
> > No it doesn't, unfortunately...
>
> OK, I start tracking down the problem a bit more deeply now.
>
> The issue happens when the first two URBs are passed to
> retire_playback_urb(). These are URBs filled before start_endpoints()
> are set, so they contain actually zero size. Even though these are
> a sort of dummy packets, the driver still tries to check with the
> queued delay account, and gives bogus errors.
>
> So, essentially the messages are harmless and nothing to worry too
> much, but surely it doesn't look sexy.
>
> The patch below should fix the problem. Please give it a try.

Yes, your patch finally fixes the problem.
Thank you Takashi-san.

--
Markus
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