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    SubjectRe: [linux-usb-devel] usb still sucks battery in -rc7-mm1
    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
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