Re: [PATCH] drm/i915: make system freeze support depend on CONFIG_ACPI_SLEEP

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 24 Jun 2014, Imre Deak <imre.deak@intel.com> wrote:
> On Tue, 2014-06-24 at 16:54 +0300, Jani Nikula wrote:
>> On Mon, 23 Jun 2014, Imre Deak <imre.deak@intel.com> wrote:
>> > To achieve further power savings during system freeze (aka connected
>> > standby, or s0ix) we have to send a PCI_D1 opregion notification. As
>> > the information about the state we're entering (system freeze,
>> > suspend to ram or suspend to disk) is only available through the ACPI
>> > subsystem, make this support depend on the relevant kconfig option.
>> > Things will still work if this option isn't set, albeit with less than
>> > optimial power saving.
>> >
>> > This also fixes a compile breakage when the option is not set introduced
>> > in
>> >
>> > commit e5747e3adcd67ae27105003ec99fb58cba180105
>> > Author: Jesse Barnes <jbarnes@virtuousgeek.org>
>> > Date:   Thu Jun 12 08:35:47 2014 -0700
>> >
>> >     drm/i915: send proper opregion notifications on suspend/resume
>> >
>> > Reported-by: Randy Dunlap <rdunlap@infradead.org>
>> > Signed-off-by: Imre Deak <imre.deak@intel.com>
>> > ---
>> >  drivers/gpu/drm/i915/i915_drv.c | 7 ++++---
>> >  1 file changed, 4 insertions(+), 3 deletions(-)
>> >
>> > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
>> > index 7ae4e2a..43dc8f7 100644
>> > --- a/drivers/gpu/drm/i915/i915_drv.c
>> > +++ b/drivers/gpu/drm/i915/i915_drv.c
>> > @@ -544,10 +544,11 @@ static int i915_drm_freeze(struct drm_device *dev)
>> >  
>> >  	i915_save_state(dev);
>> >  
>> > -	if (acpi_target_system_state() >= ACPI_STATE_S3)
>> > -		opregion_target_state = PCI_D3cold;
>> > -	else
>> > +	opregion_target_state = PCI_D3cold;
>> > +#if IS_ENABLED(CONFIG_ACPI_SLEEP)
>> 
>> Maybe this should just check for CONFIG_ACPI?
>
> I wanted to send the PCI_D1 signal only if we are sure that the target
> sleep state is S0ix (or S1/2) and fall back to the old behavior to send
> PCI_D3cold in all other cases.
>
> But you are right, it would make much sense if CONFIG_ACPI_SLEEP=n the
> target state would be always S0ix. Rafael could you confirm this?

intel_opregion_notify_adapter() is a NOP for CONFIG_ACPI=n anyway. And
AFAICT CONFIG_ACPI=y && CONFIG_ACPI_SLEEP=n is broken.

BR,
Jani.


>
> --Imre
>
>> 
>> BR,
>> Jani.
>> 
>> > +	if (acpi_target_system_state() < ACPI_STATE_S3)
>> >  		opregion_target_state = PCI_D1;
>> > +#endif
>> >  	intel_opregion_notify_adapter(dev, opregion_target_state);
>> >  
>> >  	intel_uncore_forcewake_reset(dev, false);
>> > -- 
>> > 1.8.4
>> >
>> > _______________________________________________
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>> > Intel-gfx@lists.freedesktop.org
>> > http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>> 
>

-- 
Jani Nikula, Intel Open Source Technology Center