[pulseaudio-discuss] pulseaudio-discuss Digest, Vol 6, Issue 19

[Andreas Bauer]

In Reply to: Paul Menzel <paulepanter at users.sourceforge.net>

> > Running Debian Squeeze (stable) with Kernel 3.0.1
>
> Is the PA version 0.9.21-3+squeeze1 [1]? I guess the ALSA version is
> quite old then too. PA 1.0 was released recently.

Yes, correct. I should have provided that information. ALSA is 1.0.23+dfsg-2

> Could you somehow test a more recent version. I am not sure if there is
> a live CD for that purpose or if you have a spare storage medium where
> you can try Debian Sid/unstable.

Yes, with some effort I could. But I suspect PA 1.0 will behave the same, as I understand this is expected behaviour to reduce cracking sounds etc., no? I'm hoping this behaviour could be changed by configuration settings?

Anyway, it is not really an option for me to update as I cherish the stable platform, and updating PA would require updates to lots of other stuff, too. For non-critical issues I'd rather workaround it than risk breaking something else again (have to earn my money with this machine ;)

> > So clearly, it is the power consumption of the sound chip. I suspect
> > that pulseaudio activates the sound chip even when no sound is being
> > played. Is there any way to have it only access the hardware when at
> > minimum one client is connected (e.g. audio playing)?
>
> I am not sure. 4 W power consumption of a sound chip sounds quite a lot
> to me. Additionally as written above please try a newer version.

Remember it happens just the same with aplay. Well, it has to be something downstream of ALSA then, so either ALSA userspace, ALSA driver or the hardware itself.

And probably the power is consumed by a combination of those layers, altough I suspect that the hardware plays the biggest part (waking up from power saving).

This is the power saving configured on the chip:

echo 1 > /sys/module/snd_hda_intel/parameters/power_save
echo Y > /sys/module/snd_hda_intel/parameters/power_save_controller

> You can also take a look at the ALSA Wiki [2] and provide the output of
> `alsa-info.sh` which should give a lot of useful information to the
> developers.

Output attached.

> Please open a new thread by sending a new message with an appropriate
> subject line for this topic.

Will do.

Thanks, and still hoping someone who knows the PA architecture better than me can show me a way to change this or workaround it.

Andreas
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