drm/i915: Check pipe active state in {planes,vrr}_{enabling,disabling}()

{planes,vrr}_{enabling,disabling}() are supposed to indicate
whether the specific hardware feature is supposed to be enabling
or disabling. That can only makes sense if the pipe is active
overall. So check for that before we go poking at the hardware.

I think we're semi-safe currently on due to:
- intel_pre_plane_update() doesn't get called when the pipe
  was not-active prior to the commit, but this is actually a bug.
  This saves vrr_disabling(), and vrr_enabling() is called from
  deeper down where we have already checked hw.active.
- active_planes mirrors the crtc's hw.active

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231121054324.9988-2-ville.syrjala@linux.intel.com

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

@@ -901,12 +901,18 @@ static bool needs_async_flip_vtd_wa(const struct intel_crtc_state *crtc_state)
 static bool planes_enabling(const struct intel_crtc_state *old_crtc_state,
 			    const struct intel_crtc_state *new_crtc_state)
 {
+	if (!new_crtc_state->hw.active)
+		return false;
+
 	return is_enabling(active_planes, old_crtc_state, new_crtc_state);
 }
 
 static bool planes_disabling(const struct intel_crtc_state *old_crtc_state,
 			     const struct intel_crtc_state *new_crtc_state)
 {
+	if (!old_crtc_state->hw.active)
+		return false;
+
 	return is_disabling(active_planes, old_crtc_state, new_crtc_state);
 }
 
@@ -923,6 +929,9 @@ static bool vrr_params_changed(const struct intel_crtc_state *old_crtc_state,
 static bool vrr_enabling(const struct intel_crtc_state *old_crtc_state,
 			 const struct intel_crtc_state *new_crtc_state)
 {
+	if (!new_crtc_state->hw.active)
+		return false;
+
 	return is_enabling(vrr.enable, old_crtc_state, new_crtc_state) ||
 		(new_crtc_state->vrr.enable &&
 		 (new_crtc_state->update_m_n || new_crtc_state->update_lrr ||
@@ -932,6 +941,9 @@ static bool vrr_enabling(const struct intel_crtc_state *old_crtc_state,
 static bool vrr_disabling(const struct intel_crtc_state *old_crtc_state,
 			  const struct intel_crtc_state *new_crtc_state)
 {
+	if (!old_crtc_state->hw.active)
+		return false;
+
 	return is_disabling(vrr.enable, old_crtc_state, new_crtc_state) ||
 		(old_crtc_state->vrr.enable &&
 		 (new_crtc_state->update_m_n || new_crtc_state->update_lrr ||