Hi! > > > The idea of the patches is that they will autosuspend a USB hub when it > > > has no active (i.e., unsuspended) children, and autosuspending a root hub > > > stops the USB controller from doing DMA. However, non-hub devices are not > > > yet automatically suspended, so you will have to suspend the fingerprint > > > scanner by hand. > > > > That is okay, I can do that. It saves 2 hours of battery life on my > > machine... > > Come to think of it, you don't need the autosuspend patches to turn these > devices off. You can do it right now with your existing kernel, although > it's a little easier with -mm. (The reason is that -mm contains a > development patch which ties a USB device's interfaces to the device > itself; suspending the device will automatically suspend all its > interfaces, and likewise resuming the device will automatically resume all > its interfaces. With a vanilla kernel you must manually suspend the > interfaces before you can suspend the device and manually resume them > after resuming the device.) > > Anyway, you can use the deprecated > > echo -n 2 >/sys/devices/.../power/state > > mechanism to suspend all the USB interfaces, devices, and controllers you > want -- provided you work your way up from the bottom of the device tree. > The autosuspend patch just makes it simpler, since it takes care of > suspending and resuming all the hubs for you. Thanks! That works great and gets my power consumption into reasonable range.. plus allows fan to actually stop. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
