[alsa-devel] [PATCH 6/6] ASoC/mpc5200: Add fudge factor to value reported by .pointer()

Grant Likely grant.likely at secretlab.ca
Sat Nov 7 19:19:54 CET 2009

On Sat, Nov 7, 2009 at 11:11 AM, Mark Brown
<broonie at opensource.wolfsonmicro.com> wrote:
> On Sat, Nov 07, 2009 at 01:34:55AM -0700, Grant Likely wrote:
>> ALSA playback seems to be more reliable if the .pointer() hook reports
>> a value slightly into the period, rather than right on the period
>> boundary.  This patch adds a fudge factor of 1/4 the period size
>> to better estimate the actual position of the DMA engine in the
>> audio buffer.
> It occurs to me that in terms of dealing with what's going on here this
> probably is achieving exactly the same effect as Jon's code in that it
> tells ALSA that things are a bit ahead of where the buffer started.

Possibly, but I can both reproduce and eliminate the problem Jon is
seeing regardless of whether or not this patch, so I'm not yet


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

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