On Friday, 21 of March 2008, Pavel Machek wrote: > On Thu 2008-03-20 19:01:56, Alan Stern wrote: > > On Thu, 20 Mar 2008, Rafael J. Wysocki wrote: > > > > > > > >> Well, I've been saying that for I-don't-remember-how-long: on my box, if you > > > > > >> use S5 instead of entering S4, the fan doesn't work correctly after the > > > > > >> resume. Plain and simple. > > > > > >> > > > > > >> Perhaps there's a problem with our ACPI drivers that causes this to happen, > > > > > >> but I have no idea what that can be at the moment. > > > > > > > > > > > > IMO it would be worthwhile to track this down. It's a clear indication > > > > > > that something is wrong somewhere. > > > > > > > > > > > > Could it be connected with the way the boot kernel hands control over > > > > > > to the image kernel? Presumably ACPI isn't prepared to deal with that > > > > > > sort of thing during a boot from S5. It would have to be fooled into > > > > > > thinking the two kernels were one and the same. > > > > > > > > > > It should be easy to test if it is a hand over problem, by turning off > > > > > the laptop by placing it in S5 (shutdown -h now) and then booting same > > > > > kernel again. > > > > > > > > Feel free to help with testing. > > > > > > > > I believe ACPI is simply getting confused by us overwriting memory > > > > with that from old image. I don't see how you can emulate it with > > > > shutdown. > > > > > > Well, in fact ACPI has something called the NVS memory, which we're supposed > > > to restore during the resume and which we're not doing. The problem may be > > > related to this. > > > > No, it can't be. ACPI won't expect the NVS memory to be restored > > following an S5-shutdown. In fact, as far as ACPI is concerned, > > resuming from an S5-type hibernation should not be considered a resume > > at all but just an ordinary reboot. I agree here. > > All ACPI-related memory areas in the boot kernel should be passed directly > > through to the image kernel. However, the image kernel is supposed to restore the NVS area (from the image) before executing _WAK. > How can we pass interpretter state? I do not think we do this kind of > passing. The interpreter state is passed withing the image. The platform state is not. > If it was enough to pass some static area, we could just mark it > nosave... > > Len: Is ACPI AML permitted to allocate memory (like in ACPI_ALLOC or > something)? Could we easily identify BIOS data so we could mark them > nosave? This wouldn't work even if we could (at least on x86-64). In fact I'm going to remove the 'nosave' section in the future (another thing on the todo list). Thanks, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
