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

[Peter Wu]

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 <rafael.j.wysocki@xxxxxxxxx>

Tested-by: Peter Wu <lekensteyn@xxxxxxxxx>

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?

Regards,
Peter
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