On Sun, 24 Sep 2006, Pavel Machek wrote: > 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... :-) 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. Alan Stern ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys -- and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
