On Tuesday 21 April 2009, Greg KH wrote: > > I seem to not have seen the original post about this, thanks Alan for > adding me to the cc: > > On Mon, Apr 20, 2009 at 06:11:18PM -0400, Alan Stern wrote: > > On Mon, 20 Apr 2009, Rafael J. Wysocki wrote: > > > > > On Thursday 16 April 2009, Michael Trimarchi wrote: > > > > Drivers on embedded systems would be smart enough > > > > to know that some of the devices should remain powered up, because > > > > they could still be useful even when the CPU wasn't running. > > > > The patch add the in_use attribute, that it can be used by the > > > > the drivers to avoid power down during suspend. > > I'm confused, why would a driver not know if it was in use or not? > Actually, how would it not know already by virtue of what is happening > within it (io in flight, buttons being pushed, dma streaming, etc.)? > > > > OK, so the idea is that in_use will be set by the user space for devices that > > > shouldn't be suspended. Is this correct? > > So userspace knows better than the kernel as to if a specific driver is > being used at the moment? Why is this so? The name of the flag is not the best one. :-) The flag is supposed to mean "don't suspend this device during system-wide suspend, because it's being used for something you may be unaware of". AFAICS. Best, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
