drm/amd/display: contional remove disable dig_fifo when blank

keep dig_fifo enable for test pattern generation.
Tested-by: Daniel Wheeler <Daniel.Wheeler@amd.com>
Reviewed-by: Chris Park <Chris.Park@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Charlene Liu <Charlene.Liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dc.h

@@ -873,6 +873,7 @@ struct dc_debug_options {
 	unsigned int dsc_delay_factor_wa_x1000;
 	unsigned int min_prefetch_in_strobe_ns;
 	bool disable_unbounded_requesting;
+	bool dig_fifo_off_in_blank;
 };
 
 struct gpu_info_soc_bounding_box_v1_0;

drivers/gpu/drm/amd/display/dc/dcn314/dcn314_dio_stream_encoder.c

@@ -281,7 +281,8 @@ static void enc314_stream_encoder_dp_blank(
 	enc1_stream_encoder_dp_blank(link, enc);
 
 	/* Disable FIFO after the DP vid stream is disabled to avoid corruption. */
-	enc314_disable_fifo(enc);
+	if (enc->ctx->dc->debug.dig_fifo_off_in_blank)
+		enc314_disable_fifo(enc);
 }
 
 static void enc314_stream_encoder_dp_unblank(