Re: acpi_idle: Very idle Core i7 machine never enters C3

[Matthew Garrett]

On Tue, May 25, 2010 at 01:43:26AM -0400, Len Brown wrote:

> I'm told by the hardware guys that BM_STS is _not_ always
> a NOP, and so we're not supposed to simply ignore it on C3 --
> though it should be extremely rare that we see it set.
> If it is ever set, it should go on and off depending on 
> activity on some latency sensitive device, like out on the LPC.
> It may be possible for the BIOS writer to configure the chipset
> so that BM_STS is enabled always, presumably to accomodate
> some latency sensitve device -- or maybe by mistake.

On some hardware we've seen BM_STS be enabled approximately 50% of the 
time without any obvious cause.

-- 
Matthew Garrett | mjg59@xxxxxxxxxxxxx
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