Re: x86: Increase PCIBIOS_MIN_IO to 0x1500 to fix nForce 4 suspend-to-RAM

[Linus Torvalds <torvalds@linux-foundation.org>]

On Mon, 24 Dec 2007, Carlos Corbacho wrote:
> 
> Please disregard the patch anyway - my test system was still using the custom 
> DSDT - it doesn't fix anything.

Ok, so it's not a simple IO port conflict.

And the range 0x1400-0x147f (which is apparently the ACPI block) is 
properly marked as reserved.

So the IO write to 1428 is a red herring. It's just part of the normal 
sequence to suspend-to-ram, and while it failing probably has something to 
do with the failure to s2ram, it's simply a result of ACPI doing something 
insane, and probably making some assumptions that we've broken by mistake 
when we do the higher-level device_suspend() before we do the low-level 
one.

IOW, it looks like the normal kind of ACPI mess. Color me not in the least 
surprised, and it needs somebody who understands AML and what the heck is 
supposed to happen to figure out.

The kernel doesn't do anything at all to port 1428 (since it is reserved), 
so if any write to it "fails" (how?) it's probably because the writer made 
some assumptions about system state.

			Linus