Bug 31152

Summary:	to reduce power consumption: Enable Audio codec power management
Product:	Branch p7	Reporter:	Ivan Zakharyaschev <imz>
Component:	startup	Assignee:	Andrey Cherepanov <cas>
Status:	NEW ---	QA Contact:	qa-p7 <qa-p7>
Severity:	enhancement
Priority:	P3
Version:	не указана
Hardware:	all
OS:	Linux

Description Ivan Zakharyaschev 2015-07-17 18:06:17 MSK

startup-0.9.8.38-alt1

According to powertop , on my laptop (Dell Latitude), the things that constantly consumed most power were:

Audio codec hwC0D3: Intel
Audio codec hwC0D0: IDT

and powertop even has a "tunable" to mitigate this problem: "Enable Audio codec power management", which has a huge effect indeed.

Can't such a setting be put into the default configuration?

Comment 1 Ivan Zakharyaschev 2015-07-17 18:34:23 MSK

powertop does this:

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

Comment 2 Ivan Zakharyaschev 2015-07-17 19:14:30 MSK

(В ответ на комментарий №0)

> the things that
> constantly consumed most power were:

A tiny clarification:

of course, that's probably not *the* most power consumption, but these things consumed more power than any other thing. (Around 5W-10W)

Comment 3 Ivan Zakharyaschev 2015-07-17 19:21:03 MSK

(In reply to comment #1)
> powertop does this:
> 
> echo 1 > /sys/module/snd_hda_intel/parameters/power_save

Actually, it's not a false/true parameter (as I thought).

# modinfo snd_hda_intel
....
parm:           power_save:Automatic power-saving timeout (in second, 0 = disable). (xint)
parm:           power_save_controller:Reset controller in power save mode. (bool)

One may consider other greater number of seconds, too, if one wants to enable power-saving...