Am Mittwoch 13 August 2008 16:31:03 schrieb Alan Stern: > On Wed, 13 Aug 2008, Pavel Machek wrote: > > > From: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > > > Add support for autosuspend/autoresume. Lowlevel driver can use it to > > spin the disk down and power down its SATA link, to turn off the USB > > interface, etc. > > > > Spinning down the disk is useful - saves ~0.5W here. Powering down > > SATA controller is even better -- should save ~1W. > > > > Now, I guess the patch will need to be split to small pieces for > > merge... I tried to rearrange it so that the documentation and hooks > > go before stuff that needs the hooks, and before Kconfig enabler. If > > it looks reasonably good, I'll split it into smaller pieces. > > James had a number of objections to my original patch; you can read > them here: > > https://lists.linux-foundation.org/pipermail/linux-pm/2008-March/016849.html Very well. I see a basic problem here. For USB it is necessary that child devices be suspended before anything higher up in the tree is suspended. SATA seems to be able to power down a link while the device is not suspended. In fact in true SCSI busses can be shared. So are we using the correct approach? Regards Oliver _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
