On Tue, 2007-10-16 at 16:27 +0800, Fengwei Yin wrote:
Hi all, I met a problem about period_time/buffer_time on PXA with ASOC enabled. The kernel version is 2.6.21.
The Audio stream is 32k which is not supported by PXA ASOC driver. Please refer following RATES definition for PXA2xx.
#define PXA2XX_AC97_RATES (SNDRV_PCM_RATE_8000 | SNDRV_PCM_RATE_11025 |\ SNDRV_PCM_RATE_16000 | SNDRV_PCM_RATE_22050 | SNDRV_PCM_RATE_44100 | \ SNDRV_PCM_RATE_48000)
This may be a bug in the pxa AC97 driver as most AC97 codecs can run at 32k and hence drive the AC97 link at 32k. I assume your using the WM9713 and this will request from the pxa AC97 controller when it needs PCM audio data in VRA mode. i.e. it will mark every 2 out of 3 AC97 frames (slot 3 & 4) as valid.
Can you set SNDRV_PCM_RATE_32000 and give it a try, hopefully it should work and wont require any sample rate conversion.
Liam