[alsa-devel] ALSA:usb audio Higher sample rates on usb audio no longer working.

[Takashi Iwai]

On Thu, 03 Jan 2019 12:43:54 +0100,
Con Kolivas wrote:
> 
> Upon switching from 4.19.0 to 4.20.0, pulseaudio started complaining
> that sinks that previously worked are no longer supported.
> 
> On 4.19.0 trying 24 bit 88200, 176400, and 192000 I get the following
> output from pulse.
> resampler.c: Forcing resampler 'copy', because of fixed, identical
> sample rates.sink-input.c: Created input 15 "Playback Stream" on
> alsa_output.usb-DSPeaker_Anti-Mode_X4-00.iec958-stereo with sample
> spec float32le 2ch 176400Hz and channel map front-left,front-right
> 
> Switching to 4.20 gives me:
> alsa-sink.c: Sink does not support sample rate of 176400 Hz
> and
> alsa-sink.c: Sink does not support sample rate of 88200 Hz
> and
> alsa-sink.c: Sink does not support sample rate of 192000 Hz
> 
> Sample rates of 44100, 48000, and 96000 work fine, but 88200, 176400,
> and 192000 no longer work
> 
> Switching back to 4.19 immediately fixes the issue.
> 
> 
> I tried looking through the alsa changelogs but there were too many to
> give an obvious culprit, and haven't had time to do a git bisect. If
> there's an obvious choice patch to back out I'd be grateful for the
> heads up.

Hm, through a quick glance, there hasn't been any relevant changes in
USB-audio part (sound/usb/*).  Also, the changes in sound/core/* are
irrelevant with your problem.

So I have no idea what went wrong.  The bisection, or at least,
narrowing down the commits would be helpful.


thanks,

Takashi