[lkml]   [2006]   [Sep]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: [linux-usb-devel] usb still sucks battery in -rc7-mm1

    > > 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...
    (cesky, pictures)
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2006-09-24 23:09    [W:0.022 / U:4.500 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site