[alsa-devel] ALSA DMIX support without MMAP ?

Mark Brown broonie at opensource.wolfsonmicro.com
Wed Jan 13 12:27:28 CET 2010

On Wed, Jan 13, 2010 at 09:46:36AM +0000, ANISH KUMAR wrote:

> Problem is when i am trying to use dmix plugin i am not getting any sound (logs shown below).Is it because i don't have mmap mode support on my device???

mmap is supported by the Samsung drivers.

> If yes then can't dmix work without mmap mode???   Logs shown below:
> Entered s3c24xx_pcm_hw_params,
> Entered s3c24xx_pcm_hw_params, line 330
> Entered s3c24xx_pcm_mmap
> Entered s3c24xx_pcm_prepare
> Entered s3c24xx_pcm_enqueue
> Entered s3c24xx_pcm_trigger
> Entered s3c24xx_pcm_pointer
> Entered s3c24xx_pcm_pointer res_value[0]
> snd_pcm_update_hw_ptr_pos xun: [0]occured XRUN!

This looks like the dmix data rates are getting out of sync with what
the hardware is doing.  Enabling CONFIG_SND_PCM_XRUN_DEBUG will produce
more diagnostic information from the driver side.

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