drm/i915/fbc: Use lockdep_assert_held()

Replace the mutex_is_locked() stuff with lockdep_assert_held() since
that's what it's there for.

Also sprinkle these around so that we have more or less
mirrored coverage for the enable vs. disable instead of the
current situation where the asserts seem to be more or less
randomly thrown around.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220620182917.10765-2-ville.syrjala@linux.intel.comReviewed-by: Mika Kahola <mika.kahola@intel.com>

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

@@ -670,6 +670,7 @@ static void intel_fbc_nuke(struct intel_fbc *fbc)
 {
 	struct drm_i915_private *i915 = fbc->i915;
 
+	lockdep_assert_held(&fbc->lock);
 	drm_WARN_ON(&i915->drm, fbc->flip_pending);
 
 	trace_intel_fbc_nuke(fbc->state.plane);
@@ -679,6 +680,8 @@ static void intel_fbc_nuke(struct intel_fbc *fbc)
 
 static void intel_fbc_activate(struct intel_fbc *fbc)
 {
+	lockdep_assert_held(&fbc->lock);
+
 	intel_fbc_hw_activate(fbc);
 	intel_fbc_nuke(fbc);
 
@@ -687,9 +690,7 @@ static void intel_fbc_activate(struct intel_fbc *fbc)
 
 static void intel_fbc_deactivate(struct intel_fbc *fbc, const char *reason)
 {
-	struct drm_i915_private *i915 = fbc->i915;
-
-	drm_WARN_ON(&i915->drm, !mutex_is_locked(&fbc->lock));
+	lockdep_assert_held(&fbc->lock);
 
 	if (fbc->active)
 		intel_fbc_hw_deactivate(fbc);
@@ -1227,6 +1228,8 @@ static bool __intel_fbc_pre_update(struct intel_atomic_state *state,
 	struct intel_fbc *fbc = plane->fbc;
 	bool need_vblank_wait = false;
 
+	lockdep_assert_held(&fbc->lock);
+
 	fbc->flip_pending = true;
 
 	if (intel_fbc_can_flip_nuke(state, crtc, plane))
@@ -1284,7 +1287,7 @@ static void __intel_fbc_disable(struct intel_fbc *fbc)
 	struct drm_i915_private *i915 = fbc->i915;
 	struct intel_plane *plane = fbc->state.plane;
 
-	drm_WARN_ON(&i915->drm, !mutex_is_locked(&fbc->lock));
+	lockdep_assert_held(&fbc->lock);
 	drm_WARN_ON(&i915->drm, fbc->active);
 
 	drm_dbg_kms(&i915->drm, "Disabling FBC on [PLANE:%d:%s]\n",
@@ -1299,9 +1302,7 @@ static void __intel_fbc_disable(struct intel_fbc *fbc)
 
 static void __intel_fbc_post_update(struct intel_fbc *fbc)
 {
-	struct drm_i915_private *i915 = fbc->i915;
-
-	drm_WARN_ON(&i915->drm, !mutex_is_locked(&fbc->lock));
+	lockdep_assert_held(&fbc->lock);
 
 	fbc->flip_pending = false;
 
@@ -1437,6 +1438,8 @@ static void __intel_fbc_enable(struct intel_atomic_state *state,
 		intel_atomic_get_new_plane_state(state, plane);
 	struct intel_fbc *fbc = plane->fbc;
 
+	lockdep_assert_held(&fbc->lock);
+
 	if (fbc->state.plane) {
 		if (fbc->state.plane != plane)
 			return;