[alsa-devel] [PATCH 3/4] ALSA: usb-audio: parse UAC2 sample rate ranges correctly

Daniel Mack daniel at caiaq.de
Fri Jun 11 17:18:29 CEST 2010


On Fri, Jun 11, 2010 at 05:14:57PM +0200, Clemens Ladisch wrote:
> Daniel Mack wrote:
> > On Fri, Jun 11, 2010 at 10:59:44PM +0800, Alex Lee wrote:
> > > If the device has a variable clock, it may report a RES of only 1.  So you
> > > may end up with thousands (and even millions) of sample rates.  It might be
> > > better to have separate code to cater to discrete clocks vs variable clocks.
> > 
> > AFAIK, ALSA can[...] cope with that [...]. Am I right?
> 
> Yes; set fp->rates to SNDRV_PCM_RATE_CONTINUOUS to allow all rates between
> fp->rate_min and fp->rate_max.  See, for example, parse_audio_format_rates_v1.

Ah, ok. So we should we do this for all USB devices that report a RES
value of 1. I'll respin this series then. Thanks!

Daniel



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