On Mon 2007-08-27 01:54:16, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki <rjw@xxxxxxx> > > According to the ACPI specification (eg. ACPI 2.0c, sec. 7.3.1, 7.3.3, > ACPI 3.0b, sec. 7.3.1, 7.3.3) the _GTS and _BFS global control methods should > be executed, respectively, right before entering a sleep state (S1-S4) and right > after leaving it, but we don't follow this reqirement. Namely, in our > implementation the nonboot CPUs are disabled after executing _GTS and enabled > before executing _BFS, which doesn't seem to be correct. [In fact, the ACPI > specification requires that no physical I/O and interrupt servicing be performed > after the sleep state has been left and before _BFS is executed as well as after > executing _GTS and before the sleep state is entered, but we can't follow this > requirement literally, since our AML interpreter needs to run with interrupts > enabled and we need to carry out some operations with interrupts disabled before > entering the sleep state and after leaving it.] Moreover, acpi_enable() called > after restoring the system memory state from a hibernation image should really > be executed before enabling the nonboot CPUs, since functional ACPI may be > needed for that. All of this means that we need to handle ACPI in a more fine > grained manner during suspend and hibernation. > > For this reason we can introduce new global platform callbacks prepare_late() > and finish_early() to be executed, respectively, between disabling the nonboot > CPUs and entering a sleep state and between leaving the sleep state and enabling > the nonboot CPUs. For ACPI systems they can be used to execute the _GTS and > _BFS global control methods, respectively. > > It also seems to be a good idea to introduce new hibernation-related callback > post_snapshot() to be executed after creating a hibernation image, instead of > finish() (for now, both these callbacks are defined to point to the same > function, but that will be changed in the future). > > Signed-off-by: Rafael J. Wysocki <rjw@xxxxxxx> Looks ok to me. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
