Messages in this thread | | | Date | Sun, 24 Sep 2006 23:05:27 +0200 | From | Pavel Machek <> | Subject | Re: [linux-usb-devel] usb still sucks battery in -rc7-mm1 |
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Hi!
> > I made some quick experiments, and usb still eats 4W of battery > > power. (With whole machine eating 9W, that's kind of a big deal)... > > > > This particular machine has usb bluetooth, but it can be disabled by > > firmware, and appears unplugged. (I did that). It also has fingerprint > > scanner, that can't be disabled, but that does not have driver (only > > driven by useland, and was unused in this experiment). > > > > Any ideas? > > The USB autosuspend patches are still not entirely in -mm. They contain a > couple of bugs that have to get fixed first. When they do get merged you > should see considerable improvement. Note that although they will reduce > the amount of power being used by the USB controllers and will stop the > DMA activity (thus allowing your CPU to enter C2), they won't put the > controllers into D3. For that you'll have to get PCI autosuspend... > :-)
I have not measured that, but I _hope_ drain by controller itself will not be big enough.
> In the meantime, if all you care about is power consumption there are > some things you can do. The easiest is simply to rmmod ehci-hcd, > ohci-hcd, and uhci-hcd. After all, if you're not using USB there's no > reason to let the drivers eat up memory, CPU time, and power.
Are autosuspend patches available somewhere? (Relative to -mm, or relative to 2.6.18?) I'd like to play with them... Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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