2013-03-04 14:42:55

by Peter Wu

[permalink] [raw]
Subject: Re: [Resend][PATCH] ACPI / PM: Do not power manage devices in unknown initial states

On Friday 01 February 2013 22:44:55 Rafael J. Wysocki wrote:
> On Friday, February 01, 2013 07:23:52 PM Peter Wu wrote:
> > On Thursday 31 January 2013 23:32:40 Rafael J. Wysocki wrote:
> > > In general, for ACPI device power management to work, the initial
> > > power states of devices must be known (otherwise, we wouldn't be able
> > > to keep track of power resources, for example). Hence, if it is
> > > impossible to determine the initial ACPI power states of some
> > > devices, they can't be regarded as power-manageable using ACPI.
> > >
> > >
> > >
> > > For this reason, modify acpi_bus_get_power_flags() to clear the
> > > power_manageable flag if acpi_bus_init_power() fails and add some
> > > extra fallback code to acpi_bus_init_power() to cover broken
> > > BIOSes that provide _PS0/_PS3 without _PSC for some devices.
> > >
> > >
> > >
> > > Verified to work on my HP nx6325 that has this problem.
> > >
> > >
> > >
> > > Signed-off-by: Rafael J. Wysocki <[email protected]>
> >
> >
> >
> > Tested-by: Peter Wu <[email protected]>
> >
> >
> >
> > I applied it on top of branch linux-next of repo linux-pm.
> >
> >
> >
> > Fixes the issue I had with bbswitch in Linux 3.8. Can a backport patch be
> > made available for 3.8?
>
> Yes, after this commit enters the mainline. Please ping me some time around
> 3.9-rc1.

Now that this patch has entered 3.9-rc1, can this be backported to the 3.8
series?

commit b3785492268f9f3cdaa9722facb84b266dcf8bf6
Author: Rafael J. Wysocki <[email protected]>
Date: Fri Feb 1 23:43:02 2013 +0100

Regards,
Peter