On Wednesday 05 October 2005 12:44 am, Adam Belay wrote: > On Tue, Oct 04, 2005 at 11:04:35PM -0700, David Brownell wrote: > > > > The PM core should just tell drivers to become compatible with some > > new constraint (like ACPI S3, generally implying devices in PCI D2 > > or D3; while S1 doesn't) ... and not worry about whether that involves > > a state change or not. > > > > Maybe they're already _in_ that state for example. > > Yeah, the thought occurred to me. One way of approaching the problem is to > have the PM core use logical states such as the following: > > 1.) ON > 2.) FREEZE > 3.) SUSPEND > > others? > > This is similar to our current implementation. Which is a problem, as I've described before. The logical states must be system-specific. Some systems have more states than just those three ... and in particular, the states have ** SOLID ** and ** PRECISE ** definitions. Unlike those three. At the risk of sounding like a broken record, I'll give the same example I've given before: some states may not support particular clocks, like the 48 MHz USB clock. So the driver needs to know which ** PRECISE ** system-specific state is being entered ... so it can turn off the clock if need be. - Dave
