Re: Can not play audio with screen off

Pavel Machek
2016-05-16T15:07:03Z

Hi!

> > I'm playing some more with N900, this time I'd like to use it as a
> > alarm clock...
> >
> > And now I realized I can not, because system performance is so
> > horrible with screen off that mpg123 + pulseaudio skips horribly. This
> > is without tweaking serial parameters, so CPU is definitely not going
> > into the idle/off modes.
> >
> > Loading CPU fixes the issue (I used cat /dev/zero > /dev/null).
> >
> > Hmm. And it seems to work better if I ssh in and launch mpg123
> > remotely. Weird.
> >
> > Kernel 4.5-rc0. Will try on different ones.
> >
> > Any ideas? Is there interface to tell kernel that better performance
> > is needed for a while?

> pm_qos cpu_dma_latency? Drivers will have to be properly instrumented
> with appropriate latency values -> this will control the depth in C
> states that the system will attempt. NOTE: it is a dual edged sword,
> bad configurations can result in none of the C-states being entered.

Ok, so far it looks like artefact of -rc0 kernel. Lets see if it
reappers...

Thanks,