drm/amd/display: Fix noise issue on HDMI AV mute

[Why]
When mode switching is triggered there is momentary noise visible on
some HDMI TV or displays.

[How]
Wait for 2 frames to make sure we have enough time to send out AV mute
and sink receives a full frame.

Cc: Mario Limonciello <mario.limonciello@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Wayne Lin <wayne.lin@amd.com>
Signed-off-by: Leo Ma <hanghong.ma@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/hwss/dcn30/dcn30_hwseq.c

@@ -812,10 +812,20 @@ void dcn30_set_avmute(struct pipe_ctx *pipe_ctx, bool enable)
 	if (pipe_ctx == NULL)
 		return;
 
-	if (dc_is_hdmi_signal(pipe_ctx->stream->signal) && pipe_ctx->stream_res.stream_enc != NULL)
+	if (dc_is_hdmi_signal(pipe_ctx->stream->signal) && pipe_ctx->stream_res.stream_enc != NULL) {
 		pipe_ctx->stream_res.stream_enc->funcs->set_avmute(
 				pipe_ctx->stream_res.stream_enc,
 				enable);
+
+		/* Wait for two frame to make sure AV mute is sent out */
+		if (enable) {
+			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VACTIVE);
+			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VBLANK);
+			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VACTIVE);
+			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VBLANK);
+			pipe_ctx->stream_res.tg->funcs->wait_for_state(pipe_ctx->stream_res.tg, CRTC_STATE_VACTIVE);
+		}
+	}
 }
 
 void dcn30_update_info_frame(struct pipe_ctx *pipe_ctx)