Re: Freeze due to performance_cx_lowest=LOW

On Wed, May 31, 2006 at 08:30:12AM -0700, Nate Lawson wrote:
> Yar Tikhiy wrote:
> >
> >As I reported in <20060529085723.GA98288_at_comp.chem.msu.su>, this
> >way of disabling apic didn't work in my case for some reason although
> >I had triple checked the line in device.hints.  The only mention
> >of apic in the output from sysctl -a was there irrespective of the
> >setting in device.hints: "hw.apic.enable_extint: 0".  Perhaps my
> >system has no apic at all?
> >
> >Nevertheless, removing "device apic" from the kernel changed things
> >in a way, but C3 still was unusable and the system would go to C2
> >after detecting too many short sleeps by cpu0, which was described
> >in the said message, too.
> 
> It appears that may be a different problem.  On systems with the lapic 
> issue, it seems both C2/C3 are unusable.  However, it seems C3 is 
> unusable on some other systems for a different reason.  If you could 
> look into the datasheet errata for your chipset, you might find 
> something about this.  I already have specially called out a few 
> chipsets in acpi_cpu.c to not use C3.

Alas, I've failed to find the errata.  My m/b is Epox EP-8K3AE,
based on VIA KT333:

http://www.epox.nl/products/view.php?product_id=388

> Oh and do you have usb compiled in?  C3 won't be used on systems that 
> have usb compiled in due to the constant bus master activity when usb 
> polls ports.  Anyone interested in helping with this?  It basically 
> involves adding a timeout to usb to run every 1 second or so that pokes 
> usb to check for new devices and then disables it again.  (global 
> suspend function I think).

FWIW, my system backs off from C3 to C2 even with no usb stuff in
the kernel.  Here I mean the case of no apic in the kernel either,
when my system can survive setting cx_lowest to C3 without freeze.

-- 
Yar