On Friday 09 June 2006 7:24 am, Alan Stern wrote: > On Thu, 8 Jun 2006, David Brownell wrote: > > > > A message whose source is USER or DRIVER should not be > > > allowed to resume a device that was suspended by a message > > > whose source was SYSTEM. In other words, runtime PM and > > > autoresume should not interfere with a system sleep transition. > > > > Why wouldn't that be entirely the driver's responsibility, and > > something they don't need API changes to achieve? > > Perhaps we don't need to worry about this. > > After all, in most cases it's impossible for a device which is suspended > as part of a system-sleep transition to get either a runtime-PM resume or > an autoresume request. It can only happen in situations where the > system-sleep did not first freeze all tasks. In those situations people > may agree that it is acceptable for the sleep transition to be aborted by > a user request or an autoresume. > > If that is so then yes, we don't need to alter the PM message structures > in this way. I think that's pretty much what I was saying by insisting that the driver's PM state transitions have to be correct... invalid transtions will always be invalid, regardless of whether or not the API gets complexified! :) - Dave
