drm/i915: Calculate visibility in check_plane correctly regardless of dpms.

When the crtc is configured but not active we currently clip to (0,0)x(0,0).
This results in differences in calculations depending on dpms setting.
When the crtc is enabled but not active run check_plane as if it were on,
but afterwards set plane_state->visible = false for the checks.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: Mika Kahola <mika.kahola@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1447945645-32005-13-git-send-email-maarten.lankhorst@linux.intel.com

drivers/gpu/drm/i915/intel_atomic_plane.c

@@ -152,9 +152,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
 	intel_state->clip.x1 = 0;
 	intel_state->clip.y1 = 0;
 	intel_state->clip.x2 =
-		crtc_state->base.active ? crtc_state->pipe_src_w : 0;
+		crtc_state->base.enable ? crtc_state->pipe_src_w : 0;
 	intel_state->clip.y2 =
-		crtc_state->base.active ? crtc_state->pipe_src_h : 0;
+		crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
 
 	if (state->fb && intel_rotation_90_or_270(state->rotation)) {
 		if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||

drivers/gpu/drm/i915/intel_display.c

@@ -11873,8 +11873,13 @@ int intel_plane_atomic_calc_changes(struct drm_crtc_state *crtc_state,
 	if (!was_crtc_enabled && WARN_ON(was_visible))
 		was_visible = false;
 
-	if (!is_crtc_enabled && WARN_ON(visible))
-		visible = false;
+	/*
+	 * Visibility is calculated as if the crtc was on, but
+	 * after scaler setup everything depends on it being off
+	 * when the crtc isn't active.
+	 */
+	if (!is_crtc_enabled)
+		to_intel_plane_state(plane_state)->visible = visible = false;
 
 	if (!was_visible && !visible)
 		return 0;