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From: Grant Likely <grant.likely@secretlab.ca>
Date: Wed, 11 Nov 2009 12:24:45 -0700
Message-ID: <fa686aa40911111124i12b72196xdba7000b13b3bdc@mail.gmail.com>
Subject: Re: [alsa-devel] [PATCH 2/6] ASoC/mpc5200: get rid of the appl_ptr
	tracking nonsense
To: Mark Brown <broonie@opensource.wolfsonmicro.com>
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On Wed, Nov 11, 2009 at 11:37 AM, Mark Brown
<broonie@opensource.wolfsonmicro.com> wrote:
> On Wed, Nov 11, 2009 at 11:38:06AM -0500, Jon Smirl wrote:
>> > Providing a final valid data point to the driver would possibly even
>> > make things worse since if it were used then you'd have the equivalent
>> > race where the application has initialized some data but not yet manag=
ed
>> > to update the driver to tell it it's being handed over; if the driver
>
>> That's an under run condition.
>
> Yes, of course - the issue is that this approach encourages them, making
> the system less robust if things are on the edge. =A0The mpc5200 seems to
> be not just on the edge but comfortably beyond it for some reason.

I can't reproduce the issue at all as long at the dev_dbg() statement
in the trigger stop path is disabled.  With it enabled, I hear the
problem every time.  The 5200 may not be a speedy beast, but it is
plenty fast enough to shut down the audio stream before stale data
starts getting played out.

g.

--=20
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.