arm: enable laptop-mode-tools

arm: enable laptop-mode-tools

BUG=4631
TEST=build for arm, run on device

[Sameer Nanda, 2010-07-09 16:37:23]

LGTM, although the effectiveness of laptop-mode-tools on ARM still needs to be
proven.

[piman, 2010-07-09 16:54:59]

On Fri, Jul 9, 2010 at 9:37 AM, <snanda@chromium.org> wrote:

> LGTM, although the effectiveness of laptop-mode-tools on ARM still needs to
> be
> proven.


I'm not sure why you're saying that. AFAIK laptop-mode-tools deals with
things that are orthogonal to the processor architecture (e.g. disk I/O) so
I'm not sure why it would be relevant for x86 and not ARM. In any case, the
goal is to "unfork" ARM so that the same tools are available on both
platforms.

>
>
> http://codereview.chromium.org/2943004/show
>

[Sameer Nanda, 2010-07-09 17:10:32]

On 2010/07/09 16:54:59, piman wrote:
> On Fri, Jul 9, 2010 at 9:37 AM, <mailto:snanda@chromium.org> wrote:
> 
> > LGTM, although the effectiveness of laptop-mode-tools on ARM still needs to
> > be
> > proven.
> 
> 
> I'm not sure why you're saying that. AFAIK laptop-mode-tools deals with
> things that are orthogonal to the processor architecture (e.g. disk I/O) so
> I'm not sure why it would be relevant for x86 and not ARM. In any case, the
> goal is to "unfork" ARM so that the same tools are available on both
> platforms.

Quite a few of the power management features enabled for x86 by
laptop-mode-tools such as SATA ALPM are not going to be relevant for ARMs. 
Similarly there are going to be power consumption related features that are
relevant to ARM but not x86 that would need to be addressed.

On x86 we measured power draw impact of these features to help decide whether to
enable these features or not. A similar tuning exercise would need to be done on
ARM before laptop-mode-tools improves power draw to the optimal extent.

> 
> >
> >
> > http://codereview.chromium.org/2943004/show
> >
>