Re: Does Linux 4.16.1 blast out battery time? (9h+ -> 3h+)

[Ludovic Courtès]

Hello,

Pierre Neidhardt <address@hidden> skribis:

> With a bit of tweaking, I figured that enabling power management on
> on "Audio codec":
>
>       echo '1' > '/sys/module/snd_hda_intel/parameters/power_save';
>
> helped a little bit.  But not that much.  Now on 4.14.33, I get 10h,
> while on 4.16.1 I get 5h.
>
> There is something else.

That sounds worrying.  Could you report it upstream?

> By the way, how do I make the above /sys/ tweak permanent on GuixSD?

You could do something like:

  (simple-service 'my-/sys-tweaks activation-service-type
                  #~(call-with-output-file "/sys/…"
                      (lambda (port)
                        (display "1" port))))

That said, we should probably build a higher-level
‘/sys-tweaks-service-type’ where we could directly pass pairs of file
name/values.

Would you like to give it a try?

Thanks,
Ludo’.