svn commit: r188814 - head/sys/dev/acpica

[Andriy Gapon]

on 19/02/2009 16:39 Andriy Gapon said the following:
> Author: avg
> Date: Thu Feb 19 14:39:52 2009
> New Revision: 188814
> URL: http://svn.freebsd.org/changeset/base/188814
> 
> Log:
>   acpi_cpu: fixup for PIIX4E PCI config related to C2
>   
>   This is triggered only if BIOS configures ACPI_BITREG_BUS_MASTER_RLD
>   aka BRLD_EN_BM to 1.
>   Rationale:
>   1. we do not support C3 on PIIX4E
>   2. bus master activity need not break out of C2 state
>   3. because of CPU_QUIRK_NO_BM_CTRL quirk we may reset bus master
here should have been "never" --------------------^^^
>      status which would result in immediate break out from C2
>   
>   So if you have seen
>   cpu0: too many short sleeps, backing off to C1
>   with this chipset before you may want to try cx_lowest of C2 again.

-- 
Andriy Gapon