Re: [Intel-gfx] [PATCH 6/6] drm/i915: Treat DMRRS as static DRRS

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

On Mon, 30 May 2022, Jani Nikula <jani.nikula@linux.intel.com> wrote:
> On Fri, 27 May 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
>> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>>
>> Some machines declare DRRS type = seamless, DRRS = no, DMRRS = yes.
>> I *think* DMRRS stands for "dynamcic media refresh rate", and
>> I suspect the way it's meant to work is that it lets the driver
>> switch refresh rates to match the frame rate for media playback.
>> Obviously for us all that kind of policy stuff is entirely up to
>> userspace, so the only thing we may do is make the extra refresh
>> rate(s) available.
>>
>> So let's treat this case as just static DRRS for now. In the
>> future We might want to differentiate the "seamless w/ downclocking"
>> vs. "seamless w/o downclocking" cases so that we could do seamless
>> refresh rate changes for systems that only claim to support DMRRS.
>>
>> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/125
>> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> Acked-by: Jani Nikula <jani.nikula@intel.com>

Oh, the reasoning for some Acked-bys instead of Reviewed-bys today in
this and another series:

They could all be r-b in the sense that they do what they say on the
box. But I don't really have the information to confirm they are the
right thing to do. I'm acking "let's go with this, and see where it gets
us".

Make sense?


BR,
Jani.



>
>> ---
>>  drivers/gpu/drm/i915/display/intel_bios.c | 24 +++++++++++++++++++----
>>  1 file changed, 20 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
>> index 0774238e429b..c42b9e7d0dce 100644
>> --- a/drivers/gpu/drm/i915/display/intel_bios.c
>> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
>> @@ -1279,8 +1279,16 @@ parse_panel_driver_features(struct drm_i915_private *i915,
>>  		 * static DRRS is 0 and DRRS not supported is represented by
>>  		 * driver->drrs_enabled=false
>>  		 */
>> -		if (!driver->drrs_enabled)
>> -			panel->vbt.drrs_type = DRRS_TYPE_NONE;
>> +		if (!driver->drrs_enabled && panel->vbt.drrs_type != DRRS_TYPE_NONE) {
>> +			/*
>> +			 * FIXME Should DMRRS perhaps be treated as seamless
>> +			 * but without the automatic downclocking?
>> +			 */
>> +			if (driver->dmrrs_enabled)
>> +				panel->vbt.drrs_type = DRRS_TYPE_STATIC;
>> +			else
>> +				panel->vbt.drrs_type = DRRS_TYPE_NONE;
>> +		}
>>  
>>  		panel->vbt.psr.enable = driver->psr_enabled;
>>  	}
>> @@ -1310,8 +1318,16 @@ parse_power_conservation_features(struct drm_i915_private *i915,
>>  	 * static DRRS is 0 and DRRS not supported is represented by
>>  	 * power->drrs & BIT(panel_type)=false
>>  	 */
>> -	if (!(power->drrs & BIT(panel_type)))
>> -		panel->vbt.drrs_type = DRRS_TYPE_NONE;
>> +	if (!(power->drrs & BIT(panel_type)) && panel->vbt.drrs_type != DRRS_TYPE_NONE) {
>> +		/*
>> +		 * FIXME Should DMRRS perhaps be treated as seamless
>> +		 * but without the automatic downclocking?
>> +		 */
>> +		if (power->dmrrs & BIT(panel_type))
>> +			panel->vbt.drrs_type = DRRS_TYPE_STATIC;
>> +		else
>> +			panel->vbt.drrs_type = DRRS_TYPE_NONE;
>> +	}
>>  
>>  	if (i915->vbt.version >= 232)
>>  		panel->vbt.edp.hobl = power->hobl & BIT(panel_type);

-- 
Jani Nikula, Intel Open Source Graphics Center