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

["Govindapillai, Vinod" <vinod.govindapillai@intel.com>]

Thanks Ville for the review..

Some responses and clarifications inline..

On Wed, 2025-02-05 at 14:43 +0200, Ville Syrjälä wrote:
> 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.

Okay! At this function call it is still intel_plane_state, could it be old_primary_crtc_plane_sate
and new_primary_crtc_plane_state? Or do you meant to change these parameters to old_uapi_plane_state
and new_uapi_plane_state?

> 
> > +{
> > +	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.

Yes. I was thinking if PSR can also use it at some point. But I can change it to fbc_dirty

> 
> >  };
> >  
> >  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

Ack.

> 
> > +
> > +	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

Actually, the drm_atomic_helper_damage_merged() returns false in case the plane not visible. Then
intel_plane_check_plane_damage() makes the damage area as a full plane region!

So will check if (plane_state->uapi.visible) before calling the functions to make rect relative to
viewport and plane SURF.

So the fbc_dirty will point to whole plane in such cases. And in the FBC dirty rect handling part
plane->visible condition is checked.

What do you think about this?

> 
> > +				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.

Sure. How about
skl_plane_check_fbc_dirty_relativeto_viewport()
skl_plane_check_fbc_dirty_relativeto_plane_surf()

> 
> > +{
> > +	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.

I am doing that as part of the FBC dirty prepare.
Isnt it really a FBC dirty rect validation restriction than here?

BR
Vinod

> 
> > +}
> > +
> >  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
>