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

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

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>

> ---
>  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