drm/amd/display: Add tg_init interface.

Clear OPTC underflow status when init_hw.
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/dcn10/dcn10_hw_sequencer.c

@@ -742,6 +742,8 @@ static void dcn10_init_hw(struct dc *dc)
 		hwss_wait_for_blank_complete(tg);
 
 		dcn10_power_down_fe(dc, i);
+
+		tg->funcs->tg_init(tg);
 	}
 
 	for (i = 0; i < dc->res_pool->audio_count; i++) {

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_timing_generator.c

@@ -1213,6 +1213,13 @@ void tgn10_read_otg_state(struct dcn10_timing_generator *tgn10,
 			OPTC_UNDERFLOW_OCCURRED_STATUS, &s->underflow_occurred_status);
 }
 
+static void tgn10_tg_init(struct timing_generator *tg)
+{
+	struct dcn10_timing_generator *tgn10 = DCN10TG_FROM_TG(tg);
+
+	tgn10_set_blank_data_double_buffer(tg, true);
+	REG_UPDATE(OPTC_INPUT_GLOBAL_CONTROL, OPTC_UNDERFLOW_CLEAR, 1);
+}
 
 static const struct timing_generator_funcs dcn10_tg_funcs = {
 		.validate_timing = tgn10_validate_timing,
@@ -1243,7 +1250,8 @@ static const struct timing_generator_funcs dcn10_tg_funcs = {
 		.set_test_pattern = tgn10_set_test_pattern,
 		.program_stereo = tgn10_program_stereo,
 		.is_stereo_left_eye = tgn10_is_stereo_left_eye,
-		.set_blank_data_double_buffer = tgn10_set_blank_data_double_buffer
+		.set_blank_data_double_buffer = tgn10_set_blank_data_double_buffer,
+		.tg_init = tgn10_tg_init,
 };
 
 void dcn10_timing_generator_init(struct dcn10_timing_generator *tgn10)

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_timing_generator.h

@@ -210,6 +210,7 @@ struct dcn_tg_registers {
 	SF(ODM0_OPTC_INPUT_CLOCK_CONTROL, OPTC_INPUT_CLK_ON, mask_sh),\
 	SF(ODM0_OPTC_INPUT_CLOCK_CONTROL, OPTC_INPUT_CLK_GATE_DIS, mask_sh),\
 	SF(ODM0_OPTC_INPUT_GLOBAL_CONTROL, OPTC_UNDERFLOW_OCCURRED_STATUS, mask_sh),\
+	SF(ODM0_OPTC_INPUT_GLOBAL_CONTROL, OPTC_UNDERFLOW_CLEAR, mask_sh),\
 	SF(OPPBUF0_OPPBUF_CONTROL, OPPBUF_ACTIVE_WIDTH, mask_sh),\
 	SF(OPPBUF0_OPPBUF_3D_PARAMETERS_0, OPPBUF_3D_VACT_SPACE1_SIZE, mask_sh),\
 	SF(VTG0_CONTROL, VTG0_ENABLE, mask_sh),\
@@ -330,6 +331,7 @@ struct dcn_tg_registers {
 	type OPTC_SRC_SEL;\
 	type OPTC_SEG0_SRC_SEL;\
 	type OPTC_UNDERFLOW_OCCURRED_STATUS;\
+	type OPTC_UNDERFLOW_CLEAR;\
 	type OPPBUF_ACTIVE_WIDTH;\
 	type OPPBUF_3D_VACT_SPACE1_SIZE;\
 	type VTG0_ENABLE;\

drivers/gpu/drm/amd/display/dc/inc/hw/timing_generator.h

@@ -184,6 +184,8 @@ struct timing_generator_funcs {
 	bool (*is_stereo_left_eye)(struct timing_generator *tg);
 
 	void (*set_blank_data_double_buffer)(struct timing_generator *tg, bool enable);
+
+	void (*tg_init)(struct timing_generator *tg);
 };
 
 #endif