[ltp] [W510] decreasing power use, increasing battery life: screen and lid issues

Marius Gedminas linux-thinkpad@linux-thinkpad.org
Tue, 4 Dec 2012 14:03:32 +0200

Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

On Mon, Dec 03, 2012 at 05:37:17PM -0800, Tom Roche wrote:
> Can I get advice on ways to improve a Thinkpad W510's battery life when
> running debian?

Have you tried powertop?

>I'd especially like to improve its power management,
> e.g.,
> * allowing screen brightness control via Fn-Home/Fn-End

I'd say this is worth reporting as a bug, if you can figure out which
component is dropping the ball.

What's your desktop environment?

> * making the close-lid event just turn off the screen, instead of
>   sleeping the box (i.e., suspending to RAM)
> I recently got a W510 on closeout (pretty good price). I installed LMDE
> (a testing/wheezy-based distro), but am only getting slightly more than
> 2 hours use from a fully-charged battery. This is usually plenty, but
> this week I'm traveling at a conference where the meeting rooms seem to
> have no accessible power outlets :-(
> One major problem seems to be screen power management: the screen is
> always on full brightness, and cannot be reduced by Fn-End.

One of the many possible ways of changing screen brightness is to adjust
the 'brightness' property via xrandr.  (Name of the property may depend
on your video driver -- mine's intel).

There's also xbacklight.

And some magic files in /proc or /sys that probably shouldn't be

And the screen brightness applet in GNOME System Preferences.

> Another major problem is, closing the lid does not (solely) turn off the
> screen: instead, it sleeps the box. This means I am sometimes forced to
> keep the lid up and screen on when not necessary. Note I have made the
> appropriate change in the gnome-power-manager UI, but the behavior of
> the box does not change.

For the record, in recent GNOME versions gnome-power-manager is no
longer used; power management is handled by gnome-settings-daemon's
power plugin.

It's possible that the two keep their configuration in different places.

  $ gsettings list-recursively|grep lid
  org.gnome.settings-daemon.plugins.power lid-close-ac-action 'nothing'
  org.gnome.settings-daemon.plugins.power lid-close-battery-action 'nothing'

works for me (GNOME 3.6, Ubuntu 12.10).

> I thought I could fix at least the first problem by switching the video
> driver from nouveau to nvidia proprietary, but that breaks boot, as
> described here
> http://mailman.linux-thinkpad.org/pipermail/linux-thinkpad/2012-December/=
> So I'd appreciate other suggestions (as well as advice regarding ways to
> roll back the nvidia install!)

I see that rescue mode doesn't help.  And init=3D/bin/bash is problematic
when you've got an initramfs.  Can you boot from a LiveCD, mount your
filesystem, chroot, then uninstall the nvidia packages?  You may also
need to manually mount /proc and /sys inside the chroot if
uninstallation of any of those packages triggers update-initramfs.

(I avoid laptops with NVidia graphics for a reason.)

Marius Gedminas
Favorite MAC error message: "Not enough memory to eject disk!"

Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: Digital signature

Version: GnuPG v1.4.11 (GNU/Linux)