drm/amd/display: Blank stream before destroying HDCP session

[Why]
Stream disable sequence incorretly destroys HDCP session while stream is
not blanked and while audio is not muted. This sequence causes a flash
of corruption during mode change and an audio click.

[How]
Change sequence to blank stream before destroying HDCP session. Audio will
also be muted by blanking the stream.

Cc: stable@vger.kernel.org
Signed-off-by: Jaehyun Chung <jaehyun.chung@amd.com>
Reviewed-by: Alvin Lee <Alvin.Lee2@amd.com>
Acked-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -3286,12 +3286,11 @@ void core_link_disable_stream(struct pipe_ctx *pipe_ctx)
 		core_link_set_avmute(pipe_ctx, true);
 	}
 
+	dc->hwss.blank_stream(pipe_ctx);
 #if defined(CONFIG_DRM_AMD_DC_HDCP)
 	update_psp_stream_config(pipe_ctx, true);
 #endif
 
-	dc->hwss.blank_stream(pipe_ctx);
-
 	if (pipe_ctx->stream->signal == SIGNAL_TYPE_DISPLAY_PORT_MST)
 		deallocate_mst_payload(pipe_ctx);