On Monday 19 March 2007 8:44 am, Alan Stern wrote: > On Mon, 19 Mar 2007, Shaohua Li wrote: > > > ... > > Basically we need device driver support, a kernel framework and a policy > > (determine when to change a deviceâ??s power state). > > A lot of development along these lines has already been going on in the > USB subsystem. It isn't complete yet, but a lot of the ideas you raise > have already been implemented. ISTR pointing out a few years ago that USB makes a good testbed for such things, in technical terms ... it's got the "complete problem" wrapped up in one more-or-less modern subsystem. So making it do PM well has been an object lesson in how the Linux PM infrastructure works -- or, too often, doesn't. The most troublesome spot being that ACPI interferes on PCs, so we can't yet do stuff like put EHCI/OHCI/UHCI controllers into PCI_D2 at runtime and rely on remote wakeup. But embedded Linux systems make it easy to work with saner frameworks; on those systems you can see even more of the pieces working well together. :) - Dave _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
