Re: [Jack-Devel] ALSA PCM multi plugin and xruns
On Sat, Dec 08, 2012 at 03:38:44AM -0800, Devin Anderson wrote:
> IIUC, the 'xruns' are generated because there *is* data available to
> be read, but there *isn't* enough data, which means 0 is returned,
> which incorrectly indicates that an xrun happened. The exception is
> when both `capture_avail` and `playback_avail` are both set to 0.
> Perhaps userspace hasn't been told about new samples in the kernel
> ringbuffer.
>
> I don't know whether this is a bug in the ALSA multi plugin or in
> JACK. I assume the problem is the multi plugin, as
> `snd_pcm_hw_params_set_period_size` is called to constrain the period
> size to one value, but I don't have enough of an understand of ALSA to
> know for sure. I'm hoping that someone on this list with a better
> understanding of ALSA magic will be able to answer that question for
> me.
This has been annoying me ever since I started using multiple
ice1712 cards nearly 7 years ago. I never had the time to look
into the cause. Thanks for investigating this.
John
1355049350.14178_0.ltw:2, <20121209104535.GA2556 at localhost0 dot localdomain>