Re: Centrino question

Len Brown
2004-05-27T06:22:43Z

On Tue, 2004-05-25 at 19:28, Alexander Hoogerhuis wrote:
> On Fri, 2004-05-21 at 10:38 -0700, Ow Mun Heng wrote:
> > On Fri, 2004-05-21 at 04:52, Karol Kozimor wrote:
> > > Thus wrote Cyril Wattebled:
> > > > However, I don't understand, I was told that the centrino processor and chipset
> > > > supports C3 and even C4.
> >
> > C3 is Supported
> >
> >
> > active state: C2
> > default state: C1
> > bus master activity: ffffffff
> > states:
> > C1: promotion[C2] demotion[--] latency[000] usage[01028830]
> > *C2: promotion[C3] demotion[C1] latency[050] usage[04785987]
> > C3: promotion[--] demotion[C2] latency[050] usage[00001327]
> >
> > This is a Dell D600 1.4g. c3 values are low because I have the USB mouse
> > on right now. (note the fffffff??)
> >
> > I've tested it with and w/o C3. The difference in the battery lifetime
> > was only very minmal. I got like maybe 10 mins extra.

> > I last 2:30 on Linux and 3h on Windows.
> >
> > Batt Life Sucks..

try dimming the display.

>
> I've been through tracking down what disables C3 on my laptop (HP
> nc6000). It all happens when the uhci-hci USB drviver goes in. When I
> queried about it on lkml a while back it was due tro some support
> lacking in the UHCI dirvers as of yet.

USB needs to do a better job of recognizing that it is idle.
It isn't really a USB bug, or a missing feature -- more of
a "system integration" issue...

-Len