On Sun, 21.02.10 12:35, Kai Vehmanen (kvehmanen@eca.cx) wrote:
But you can query the SNDRV_PCM_INFO_BATCH flag (it's set by e.g. the USB driver) and adjust your hrtimer-based application's logic based on that (if set, assume hw_ptr will jump in bursts). I know, not really ideal (you essentially have to e.g. disable PA glitch-free for these cards currently).
This mean that the wake up time cannot be calculated using as number of sample/rate since the fuction is not linear especially when using max buffer size , min period --> max period size is much greater than the watermark
Yep, that's what SNDRV_PCM_INFO_BATCH flag warns you about.
Hmm, could you elaborate a little about SNDRV_PCM_INFO_BATCH? What exactly does that mean in general and especially for the timer based audio scheduling?
I am currently not making use of this, but should I?
I cannot find much documentation about this, can you enlighten me?
I assume this is exposed to userspace via snd_pcm_hw_params_is_batch()?
Lennart