Re: [PATCH 1/2] drm/i915/display: After joiner compute pfit_dst

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

On Thu, Dec 12, 2024 at 08:03:28PM +0530, Nemesa Garg wrote:
> In panel fitter/pipe scaler scenario the pch_pfit configuration
> currently takes place before accounting for pipe_src width for
> joiner. This causes issue when pch_pfit and joiner get enabled
> together.So once pipe src is computed adjust the pfit_dst.
> It can be done by computing per pipe output area first and then
> and then find the intersection of above area with pfit_dst and
> then adjust the coordinates.
> 
> Signed-off-by: Nemesa Garg <nemesa.garg@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 41 ++++++++++++++++++++
>  1 file changed, 41 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 21319f753a34..7be2ea11b8b0 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -2563,6 +2563,36 @@ static int intel_crtc_compute_pipe_src(struct intel_crtc_state *crtc_state)
>  	return 0;
>  }
>  
> +/*
> + * The x-coordinate for Primary should be calculated in such a way
> + * that it remains consistent whether the pipes are joined or not.
> + * This means we need to consider the full width of the display even
> + * when the pipes are joined. The x-coordinate for secondaries is 0
> + * because it starts at the leftmost point of its own display area,
> + * ensuring that the framebuffer is centered within Pipe B’s portion
> + * of the overall display.
> + */
> +static int intel_crtc_compute_pfit(struct intel_atomic_state *state,
> +				   struct intel_crtc_state *crtc_state)
> +{
> +	struct drm_display_mode *mode = &crtc_state->hw.pipe_mode;

const struct drm_display_mode *pipe_mode = ...

> +	struct drm_rect area;
> +
> +	if (!crtc_state->pch_pfit.enabled)
> +		return 0;
> +
> +	drm_rect_init(&area, 0, 0,

This needs a proper x offset to match the pipe's positon in
the overall screen layout (can be determined similarly to
intel_joiner_adjust_pipe_src(), except using crtc_hdisplay
as the width instead of the pipe_src width).

> +		      mode->crtc_hdisplay,
> +		      mode->crtc_vdisplay);
> +
> +	if (!drm_rect_intersect(&crtc_state->pch_pfit.dst, &area))
> +		return -EINVAL;
> +
> +	drm_rect_translate(&crtc_state->pch_pfit.dst, -area.x1, -area.y1);

And this needs to remove the same offset we added originally.

> +
> +	return 0;
> +}
> +
>  static int intel_crtc_compute_pipe_mode(struct intel_crtc_state *crtc_state)
>  {
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
> @@ -2645,6 +2675,10 @@ static int intel_crtc_compute_config(struct intel_atomic_state *state,
>  	if (ret)
>  		return ret;
>  
> +	ret = intel_crtc_compute_pfit(state, crtc_state);
> +	if (ret)
> +		return ret;
> +
>  	intel_crtc_compute_pixel_rate(crtc_state);
>  
>  	if (crtc_state->has_pch_encoder)
> @@ -4865,6 +4899,13 @@ copy_joiner_crtc_state_modeset(struct intel_atomic_state *state,
>  		drm_dp_tunnel_ref_get(primary_crtc_state->dp_tunnel_ref.tunnel,
>  				      &secondary_crtc_state->dp_tunnel_ref);
>  
> +	if (secondary_crtc_state->pch_pfit.enabled) {
> +		struct drm_rect *dst = &secondary_crtc_state->pch_pfit.dst;
> +		int y = dst->y1;
> +
> +		drm_rect_translate_to(dst, 0, y);
> +	}
> +
>  	copy_joiner_crtc_state_nomodeset(state, secondary_crtc);
>  
>  	secondary_crtc_state->uapi.mode_changed = primary_crtc_state->uapi.mode_changed;
> -- 
> 2.25.1

-- 
Ville Syrjälä
Intel