Re: [PATCH v6 4/7] drm/i915/xe3: update and store the plane damage clips

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

On Thu, Jan 30, 2025 at 11:00:23PM +0200, Vinod Govindapillai wrote:
> Userspace can pass damage area clips per plane to track
> changes in a plane and some display components can utilze
> these damage clips for efficiently handling use cases like
> FBC, PSR etc. A merged damage area is generated and its
> coordinates are updated relative to viewport and HW and
> stored in the plane_state. This merged damage areas will be
> used for FBC dirty rect support in xe3 in the follow-up
> patch.
> 
> Big thanks to Ville Syrjala for his contribuitions in shaping
> up of this series.
> 
> v1: - Move damage_merged helper to cover bigjoiner case and use
>     the correct plane state for damage find helper (Ville)
>     - Damage handling code under HAS_FBC_DIRTY_RECT() so the
>     the related part will be executed only for xe3+
>     - Changed dev_priv to i915 in one of the functions
> 
> Signed-off-by: Vinod Govindapillai <vinod.govindapillai@intel.com>
> ---
>  .../gpu/drm/i915/display/intel_atomic_plane.c | 28 ++++++++++++
>  .../drm/i915/display/intel_display_types.h    |  2 +
>  .../drm/i915/display/skl_universal_plane.c    | 45 +++++++++++++++++--
>  3 files changed, 71 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> index c558143f4f82..f55f7044dc67 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> @@ -36,6 +36,7 @@
>  
>  #include <drm/drm_atomic_helper.h>
>  #include <drm/drm_blend.h>
> +#include <drm/drm_damage_helper.h>
>  #include <drm/drm_fourcc.h>
>  #include <drm/drm_gem.h>
>  #include <drm/drm_gem_atomic_helper.h>
> @@ -322,6 +323,25 @@ static void intel_plane_clear_hw_state(struct intel_plane_state *plane_state)
>  	memset(&plane_state->hw, 0, sizeof(plane_state->hw));
>  }
>  
> +static void
> +intel_plane_check_plane_damage(struct intel_plane_state *new_plane_state,
> +			       const struct intel_plane_state *old_primary_plane_state,
> +			       const struct intel_plane_state *new_primary_plane_state)

"primary_plane_state" is a confusing name because "primary plane"
generally means something totally different than what's used here.
probably we should just call these "uapi_plane_state" or something.

> +{
> +	struct intel_display *display = to_intel_display(new_plane_state);
> +	struct drm_rect *damage_merged = &new_plane_state->damage_merged;
> +
> +	if (!HAS_FBC_DIRTY_RECT(display))
> +		return;
> +
> +	if (!drm_atomic_helper_damage_merged(&old_primary_plane_state->uapi,
> +					     &new_primary_plane_state->uapi,
> +					     damage_merged))
> +		/* Incase helper fails, mark whole plane region as damage */
> +		*damage_merged =
> +			drm_plane_state_src(&new_primary_plane_state->uapi);
> +}
> +
>  void intel_plane_copy_uapi_to_hw_state(struct intel_plane_state *plane_state,
>  				       const struct intel_plane_state *from_plane_state,
>  				       struct intel_crtc *crtc)
> @@ -691,6 +711,7 @@ int intel_plane_atomic_check(struct intel_atomic_state *state,
>  	const struct intel_plane_state *old_plane_state =
>  		intel_atomic_get_old_plane_state(state, plane);
>  	const struct intel_plane_state *new_primary_crtc_plane_state;
> +	const struct intel_plane_state *old_primary_crtc_plane_state;
>  	struct intel_crtc *crtc = intel_crtc_for_pipe(display, plane->pipe);
>  	const struct intel_crtc_state *old_crtc_state =
>  		intel_atomic_get_old_crtc_state(state, crtc);
> @@ -705,10 +726,17 @@ int intel_plane_atomic_check(struct intel_atomic_state *state,
>  
>  		new_primary_crtc_plane_state =
>  			intel_atomic_get_new_plane_state(state, primary_crtc_plane);
> +		old_primary_crtc_plane_state =
> +			intel_atomic_get_old_plane_state(state, primary_crtc_plane);
>  	} else {
>  		new_primary_crtc_plane_state = new_plane_state;
> +		old_primary_crtc_plane_state = old_plane_state;
>  	}
>  
> +	intel_plane_check_plane_damage(new_plane_state,
> +				       old_primary_crtc_plane_state,
> +				       new_primary_crtc_plane_state);
> +
>  	intel_plane_copy_uapi_to_hw_state(new_plane_state,
>  					  new_primary_crtc_plane_state,
>  					  crtc);
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index cb51b7936f93..8d53bcca9614 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -695,6 +695,8 @@ struct intel_plane_state {
>  	u64 ccval;
>  
>  	const char *no_fbc_reason;
> +
> +	struct drm_rect damage_merged;

Since this is only used for the fbc stuff I would just
call it 'fbc_dirty'. Though I suppose if we were to also
use this for the PSR stuff then "damage" might be a decent
name. The _merged part is pointless imo.

>  };
>  
>  struct intel_initial_plane_config {
> diff --git a/drivers/gpu/drm/i915/display/skl_universal_plane.c b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> index 301ad3a22c4c..b90a7d52c071 100644
> --- a/drivers/gpu/drm/i915/display/skl_universal_plane.c
> +++ b/drivers/gpu/drm/i915/display/skl_universal_plane.c
> @@ -2249,11 +2249,42 @@ static void check_protection(struct intel_plane_state *plane_state)
>  		!plane_state->decrypt;
>  }
>  
> +static void
> +skl_plane_check_damage_with_viewport(struct intel_plane_state *plane_state)
> +{
> +	struct drm_rect *damage_merged = &plane_state->damage_merged;
> +	const struct drm_framebuffer *fb = plane_state->hw.fb;
> +	unsigned int rotation = plane_state->hw.rotation;
> +	struct drm_rect *src = &plane_state->uapi.src;

const

> +
> +	if (drm_rotation_90_or_270(rotation)) {
> +		drm_rect_rotate(damage_merged, fb->width, fb->height,

fb might be NULL here. 

I guess we might as well do something like:
if (!visible) -> make the dirty rect empty

> +				DRM_MODE_ROTATE_270);
> +		drm_rect_translate(damage_merged, -(src->y1 >> 16),
> +				   -(src->x1 >> 16));
> +	} else {
> +		drm_rect_translate(damage_merged, -(src->x1 >> 16),
> +				   -(src->y1 >> 16));
> +	}
> +}
> +
> +static void
> +skl_plane_check_damage_with_plane_surf(struct intel_plane_state *plane_state)

the "with" stuff in the name is a bit confusing. What we are doing 
is make the rectangle relative to plane SURF. Same story with the
other function.

> +{
> +	struct drm_rect *damage_merged = &plane_state->damage_merged;
> +	struct drm_rect src;
> +
> +	drm_rect_fp_to_int(&src, &plane_state->uapi.src);
> +	drm_rect_translate(damage_merged, src.x1, src.y1);
> +	drm_rect_intersect(damage_merged, &src);

Missing the "make it at last one scanline" here. Though if we do
decide to use this also for PSR then I guess we'd need to handle
that elsewhere. For now it could just be here.

> +}
> +
>  static int skl_plane_check(struct intel_crtc_state *crtc_state,
>  			   struct intel_plane_state *plane_state)
>  {
> +	struct intel_display *display = to_intel_display(crtc_state);
>  	struct intel_plane *plane = to_intel_plane(plane_state->uapi.plane);
> -	struct drm_i915_private *dev_priv = to_i915(plane->base.dev);
> +	struct drm_i915_private *i915 = to_i915(plane->base.dev);
>  	const struct drm_framebuffer *fb = plane_state->hw.fb;
>  	int min_scale = DRM_PLANE_NO_SCALING;
>  	int max_scale = DRM_PLANE_NO_SCALING;
> @@ -2266,7 +2297,7 @@ static int skl_plane_check(struct intel_crtc_state *crtc_state,
>  	/* use scaler when colorkey is not required */
>  	if (!plane_state->ckey.flags && skl_fb_scalable(fb)) {
>  		min_scale = 1;
> -		max_scale = skl_plane_max_scale(dev_priv, fb);
> +		max_scale = skl_plane_max_scale(i915, fb);
>  	}
>  
>  	ret = intel_atomic_plane_check_clipping(plane_state, crtc_state,
> @@ -2274,6 +2305,9 @@ static int skl_plane_check(struct intel_crtc_state *crtc_state,
>  	if (ret)
>  		return ret;
>  
> +	if (HAS_FBC_DIRTY_RECT(display))
> +		skl_plane_check_damage_with_viewport(plane_state);
> +
>  	ret = skl_check_plane_surface(plane_state);
>  	if (ret)
>  		return ret;
> @@ -2289,6 +2323,9 @@ static int skl_plane_check(struct intel_crtc_state *crtc_state,
>  	if (ret)
>  		return ret;
>  
> +	if (HAS_FBC_DIRTY_RECT(display))
> +		skl_plane_check_damage_with_plane_surf(plane_state);
> +
>  	ret = skl_plane_check_nv12_rotation(plane_state);
>  	if (ret)
>  		return ret;
> @@ -2301,12 +2338,12 @@ static int skl_plane_check(struct intel_crtc_state *crtc_state,
>  
>  	plane_state->ctl = skl_plane_ctl(crtc_state, plane_state);
>  
> -	if (DISPLAY_VER(dev_priv) >= 10)
> +	if (DISPLAY_VER(display) >= 10)
>  		plane_state->color_ctl = glk_plane_color_ctl(crtc_state,
>  							     plane_state);
>  
>  	if (intel_format_info_is_yuv_semiplanar(fb->format, fb->modifier) &&
> -	    icl_is_hdr_plane(dev_priv, plane->id))
> +	    icl_is_hdr_plane(i915, plane->id))
>  		/* Enable and use MPEG-2 chroma siting */
>  		plane_state->cus_ctl = PLANE_CUS_ENABLE |
>  			PLANE_CUS_HPHASE_0 |
> -- 
> 2.43.0

-- 
Ville Syrjälä
Intel