drm/vc4: hdmi: Update all the planes if the TV margins are changed

On VC4, the TV margins on the HDMI connector are implemented by scaling
the planes.

However, if only the TV margins or the connector are changed by a new
state, the planes ending up on that connector won't be. Thus, they won't
be updated properly and we'll effectively ignore that change until the
next commit affecting these planes.

Let's make sure to add all the planes attached to the connector so that
we can update them properly.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20221207-rpi-hdmi-improvements-v3-2-bdd54f66884e@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -535,6 +535,32 @@ static int vc4_hdmi_connector_atomic_check(struct drm_connector *connector,
 	if (!crtc)
 		return 0;
 
+	if (old_state->tv.margins.left != new_state->tv.margins.left ||
+	    old_state->tv.margins.right != new_state->tv.margins.right ||
+	    old_state->tv.margins.top != new_state->tv.margins.top ||
+	    old_state->tv.margins.bottom != new_state->tv.margins.bottom) {
+		struct drm_crtc_state *crtc_state;
+		int ret;
+
+		crtc_state = drm_atomic_get_crtc_state(state, crtc);
+		if (IS_ERR(crtc_state))
+			return PTR_ERR(crtc_state);
+
+		/*
+		 * Strictly speaking, we should be calling
+		 * drm_atomic_helper_check_planes() after our call to
+		 * drm_atomic_add_affected_planes(). However, the
+		 * connector atomic_check is called as part of
+		 * drm_atomic_helper_check_modeset() that already
+		 * happens before a call to
+		 * drm_atomic_helper_check_planes() in
+		 * drm_atomic_helper_check().
+		 */
+		ret = drm_atomic_add_affected_planes(state, crtc);
+		if (ret)
+			return ret;
+	}
+
 	if (old_state->colorspace != new_state->colorspace ||
 	    !drm_connector_atomic_hdr_metadata_equal(old_state, new_state)) {
 		struct drm_crtc_state *crtc_state;