drm/amd/display: reset transfer_func to NULL on release

Signed-off-by: Yongqiang Sun <yongqiang.sun@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/core/dc_stream.c

@@ -89,9 +89,11 @@ static bool construct(struct core_stream *stream,
 static void destruct(struct core_stream *stream)
 {
 	dc_sink_release(&stream->sink->public);
-	if (stream->public.out_transfer_func != NULL)
+	if (stream->public.out_transfer_func != NULL) {
 		dc_transfer_func_release(
 				stream->public.out_transfer_func);
+		stream->public.out_transfer_func = NULL;
+	}
 }
 
 void dc_stream_retain(const struct dc_stream *dc_stream)

drivers/gpu/drm/amd/display/dc/core/dc_surface.c

@@ -71,11 +71,15 @@ static bool construct(struct dc_context *ctx, struct surface *surface)
 
 static void destruct(struct surface *surface)
 {
-	if (surface->protected.public.gamma_correction != NULL)
+	if (surface->protected.public.gamma_correction != NULL) {
 		dc_gamma_release(surface->protected.public.gamma_correction);
-	if (surface->protected.public.in_transfer_func != NULL)
+		surface->protected.public.gamma_correction = NULL;
+	}
+	if (surface->protected.public.in_transfer_func != NULL) {
 		dc_transfer_func_release(
 				surface->protected.public.in_transfer_func);
+		surface->protected.public.in_transfer_func = NULL;
+	}
 }
 
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