Re: [PATCH 16/22] drm/i915/vrr: Use fixed timings for platforms that support VRR

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, Mar 04, 2025 at 01:49:42PM +0530, Ankit Nautiyal wrote:
> For fixed refresh rate use fixed timings for all platforms that support
> VRR. For this add checks to avoid computing and reading VRR for
> platforms that do not support VRR.
> 
> v2: Avoid touching check for VRR_CTL_FLIP_LINE_EN. (Ville)
> 
> Signed-off-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_vrr.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_vrr.c b/drivers/gpu/drm/i915/display/intel_vrr.c
> index 97040ab9ed86..11f23affd13a 100644
> --- a/drivers/gpu/drm/i915/display/intel_vrr.c
> +++ b/drivers/gpu/drm/i915/display/intel_vrr.c
> @@ -347,6 +347,9 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
>  	struct drm_display_mode *adjusted_mode = &crtc_state->hw.adjusted_mode;
>  	int vmin, vmax;
>  
> +	if (!HAS_VRR(display))
> +		return;
> +
>  	/*
>  	 * FIXME all joined pipes share the same transcoder.
>  	 * Need to account for that during VRR toggle/push/etc.
> @@ -370,8 +373,7 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
>  		vmax = vmin;
>  	}
>  
> -	if (vmin >= vmax)
> -		return;
> +	vmin = intel_vrr_compute_vmin(crtc_state);

Didn't we already do that?

>  
>  	crtc_state->vrr.vmin = vmin;
>  	crtc_state->vrr.vmax = vmax;
> @@ -385,7 +387,7 @@ intel_vrr_compute_config(struct intel_crtc_state *crtc_state,
>  	 */
>  	crtc_state->vrr.vmin -= intel_vrr_flipline_offset(display);
>  
> -	if (crtc_state->uapi.vrr_enabled)
> +	if (crtc_state->uapi.vrr_enabled && vmin < vmax)
>  		intel_vrr_compute_vrr_timings(crtc_state);
>  	else if (is_cmrr_frac_required(crtc_state) && is_edp)
>  		intel_vrr_compute_cmrr_timings(crtc_state);
> @@ -659,6 +661,9 @@ void intel_vrr_get_config(struct intel_crtc_state *crtc_state)
>  	enum transcoder cpu_transcoder = crtc_state->cpu_transcoder;
>  	u32 trans_vrr_ctl, trans_vrr_vsync;
>  
> +	if (!HAS_VRR(display))
> +		return;
> +

The caller already checks that, so should not be needed here.

>  	trans_vrr_ctl = intel_de_read(display,
>  				      TRANS_VRR_CTL(display, cpu_transcoder));
>  
> -- 
> 2.45.2

-- 
Ville Syrjälä
Intel