Re: C2, C3 and bus master activity

[pumpkin <pumpkin-Mmb7MZpHnFY@public.gmane.org>]

Hello

> This is interesting, I have a theory why the IBM laptops keep crashing
> when you use the the deeper sleep states. 

Well,... i don't really understand what is going on here. 

From time-to-time Xorg tries to load and crashs even before starting the new 
logfile. But if it gets past that point everything works fine. And even with 
the stock kernel and every module (including ieee1394...) loaded the CPU 
enters C4. The BIOS/CMOS/Laptop... whatever has changed it's behavior after 
my first tests. Maybe it has something to do with running of AC or battery.

Once i have the time to an intensive test with all combinations (w/ and w/o 
battery, w/ and w/o AC, w/ and w/o 1394 at startup ... ) i will send you my 
results. Any logs/files that are important to you ?

> Can you try out something for 
> me ?

Sure, but not today. I will recompile the kernel once again but with debugging 
enabled. 

cu

> First try to load or do something, that would cause your laptop to
> disable the C4 state. If this hapens, you shuld see in your logs (as
> long as you compiled your kernel with debug messages) something like
> \_SB.CPU0, 0x81. This means, that your laptop has changed the available
> C-States. (this should also appear, if you unload eee1394, eth1394 and
> ohic1394)
>
> I saw some places in the ACPI code, where the C-States are not correctly
> deleted after this event, and my theory is that this actually crashes
> some IBM laptops.



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