[alsa-devel] [RFC][PATCH] ASoC: OMAP: Fix capture pointer handling for OMAP1510 to work correctly with recent ALSA PCM code

Jarkko Nikula jhnikula at gmail.com
Mon Mar 29 10:54:59 CEST 2010

On Sun, 28 Mar 2010 22:29:29 +0200
Janusz Krzysztofik <jkrzyszt at tis.icnet.pl> wrote:

> With recent (2.6.34) chnages in PCM handling, capture stopped working on my 
> OMAP1510 based Amstrad Delta videophone.
> Using 2.6.34-rc2, I was able to correct the problem in 3 different ways:
> 1. reverting commit 7b3a177b0d4f92b3431b8dca777313a07533a710,
> 2. enabling additional jiffies check with
> 	echo 4 >/proc/asound/card0/pcm0c0/xrun_debug
> 3. applying the patch below.
> Since I wasn't able to reproduce the problem on my i686 PC, I guess the 
> problem is probably machine specific.
> The patch reuses the method for software emulation of missing hardware 
> pointer, already implemented for playback on OMAP1510. It's possible that 
> event if a hardware pointer is available for capture on this machine, its 
> behaviour may be not compatible with what upper layer expects.
> If you think the problem may be more general and should be solved differently, 
> on a higher level, I can try to work more on it if you give me a hint.
I don't have anything against this patch as it makes the
playback/capture code uniform on 1510 but I don't understand why the
capture broke now if it was working before.

What I was thinking if there has been always some overruns which were
not detected on 2.6.34-rc anymore and that caused somehow the capture
not working on 1510. Could you try does a patch below have any effect?



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