[alsa-devel] Unable to find an usable access for 'default'

Timur Tabi timur at freescale.com
Sat Jul 7 00:32:37 CEST 2007

Clemens Ladisch wrote:

> ALSA-lib's access type specifies whether to use mmap or not, and whether
> the sample are interleaved or not.  (The SNDRV_PCM_INFO_*INTERLEAVED and
> SNDRV_PCM_INFO_MMAP* flags specify the capabilities of the device.)

Is mmap support ever required?  I don't have that support turned on in my PCM driver, so 
could that cause some ALSA applications to fail to match?

> Look at the values in the snd_pcm_hardware structure and at the
> constraints the driver adds manually, if there are any.

Ok, I think I fixed some issues there, but I'm still having problems.

I think part of the problem is that I'm telling ALSA that I only support these sample 
rates: 192000, 96000, 64000, 48000, 32000, and 16000.  For playback, I'm using alsaplayer 
to play an MP3.  Could it be that alsaplayer is picking a sample rate like 44100 and since 
it doesn't find a match, it's failing?  I thought ALSA always did sample rate conversion. 
  Is that not true?

Timur Tabi
Linux Kernel Developer @ Freescale

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