Commit 4ef619a7 authored by Ville Syrjälä's avatar Ville Syrjälä Committed by Manasi Navare
Browse files

drm/i915/display: Helpers for VRR vblank min and max start 



With VRR the earliest the registers can get latched are at
flipline decision boundary, calculate that as vrr_vmin_vblank_start()
and the latest the regsiters can get latched are vmax decision boundary
calculate that as vrr_vmax_vblank_start()

v2:
* Remove TODO and adjust extra scanline const (Manasi)

Signed-off-by: default avatarManasi Navare <manasi.d.navare@intel.com>
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: default avatarManasi Navare <manasi.d.navare@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210122232647.22688-15-manasi.d.navare@intel.com
parent c7f0f437

drivers/gpu/drm/i915/display/intel_vrr.c

+36 −0
Original line number Diff line number Diff line
@@ -45,6 +45,42 @@ intel_vrr_check_modeset(struct intel_atomic_state *state) 
	}

}



/*

 * Without VRR registers get latched at:

 *  vblank_start

 *

 * With VRR the earliest registers can get latched is:

 *  intel_vrr_vmin_vblank_start(), which if we want to maintain

 *  the correct min vtotal is >=vblank_start+1

 *

 * The latest point registers can get latched is the vmax decision boundary:

 *  intel_vrr_vmax_vblank_start()

 *

 * Between those two points the vblank exit starts (and hence registers get

 * latched) ASAP after a push is sent.

 *

 * framestart_delay is programmable 0-3.

 */

static int intel_vrr_vblank_exit_length(const struct intel_crtc_state *crtc_state)

{

	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);

	struct drm_i915_private *i915 = to_i915(crtc->base.dev);



	/* The hw imposes the extra scanline before frame start */

	return crtc_state->vrr.pipeline_full + i915->framestart_delay + 1;

}



int intel_vrr_vmin_vblank_start(const struct intel_crtc_state *crtc_state)

{

	/* Min vblank actually determined by flipline that is always >=vmin+1 */

	return crtc_state->vrr.vmin + 1 - intel_vrr_vblank_exit_length(crtc_state);

}



int intel_vrr_vmax_vblank_start(const struct intel_crtc_state *crtc_state)

{

	return crtc_state->vrr.vmax - intel_vrr_vblank_exit_length(crtc_state);

}



void

intel_vrr_compute_config(struct intel_crtc_state *crtc_state,

			 struct drm_connector_state *conn_state)

drivers/gpu/drm/i915/display/intel_vrr.h

+2 −0
Original line number Diff line number Diff line
@@ -27,5 +27,7 @@ void intel_vrr_send_push(const struct intel_crtc_state *crtc_state); 
void intel_vrr_disable(const struct intel_crtc_state *old_crtc_state);

void intel_vrr_get_config(struct intel_crtc *crtc,

			  struct intel_crtc_state *crtc_state);

int intel_vrr_vmax_vblank_start(const struct intel_crtc_state *crtc_state);

int intel_vrr_vmin_vblank_start(const struct intel_crtc_state *crtc_state);



#endif /* __INTEL_VRR_H__ */