[alsa-devel] Requiring the same sample rate for playback and record?

[Takashi Iwai]

At Wed, 16 Jul 2008 10:11:27 -0500,
Timur Tabi wrote:
> 
> Takashi Iwai wrote:
> 
> > In a simple case, you don't need hw_constraint functions.  Just
> > override the corresponding fields of runtime->hw in open callback.
> > 
> > For example, pci/via82xx.c sets the current rate value to
> > runtime->hw.rate_min/max if there is another stream.
> 
> Are you talking about this code:
> 
> 	} else {
> 		/* a fixed rate */
> 		runtime->hw.rates = SNDRV_PCM_RATE_KNOT;
> 		runtime->hw.rate_max = runtime->hw.rate_min = ratep->rate;
> 	}
> 
> Last I heard, ASoC doesn't work with SNDRV_PCM_RATE_KNOT.  But I think I can
> still use this method.  I'll just need to use a real SNDRV_PCM_RATE_xxx value.

KNOT is set there just because it can be any rate (and easy to
handle).  If the rate is a normal one, e.g. 48kHz, then you can set
the appropriate bitflag in hw.rates.


Takashi