Re: [PATCH] cpuidle: fix new C-states not functional after AC disconnect

From: Daniel Lezcano
Date: Sun Jan 13 2013 - 09:41:25 EST


On 01/13/2013 01:34 PM, Thomas Schlichter wrote:
> Hi,
>
> there is a long-standing regression about new C-states not working after
> disconnecting AC power from a laptop if the cpuidle driver "acpi-idle" is
> used. It was reported here:
>
> [1] https://bugzilla.kernel.org/show_bug.cgi?id=42870 (March 5th 2012)
> [2] https://bugzilla.kernel.org/show_bug.cgi?id=43349 (June 7th 2012)
> [3] https://lkml.org/lkml/2012/10/16/518 (October 19th 2012)
>
> In [1] Andreas proposed a patch that initialized the missing power_usage
> values from within acpi_idle in the same way as cpuidle does.
> In [2] I proposed a patch to use the power values provided by ACPI to
> initialize the power_usage variables.
> In [3] Julius proposed a patch to call the initialization function
> set_power_states() not only once, but always when the C-states change.
>
> Currently, Daniel Lezcano seems to be working on an intrusive change of not
> using the power_usage value at all for choosing a C-state:
>
> [4] https://lkml.org/lkml/2012/12/14/155
>
> As I could not find any of these patches in any git trees to be merged for
> 3.8, I propose an other, least intrusive patch for the time being. It is
> attached an initializes _all_ power_usage values in the first place.
>
> As this is a real power consumption regression since 3.2, I really ask you to
> apply anything and push it to stable, too!

Rafael, is possible to apply the patch [1/2] I previously sent ?

https://patchwork.kernel.org/patch/1878691/

So we get this bug fixed.

I will resend the patch [2/2] as soon as possible.

-- Daniel


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