drm/amd/display: resume from S3 bypass power down HW block.

Signed-off-by: Charlene Liu <charlene.liu@amd.com>
Reviewed-by: Krunoslav Kovac <Krunoslav.Kovac@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/bios/bios_parser.c

@@ -3803,6 +3803,7 @@ static const struct dc_vbios_funcs vbios_funcs = {
 
 	/* bios scratch register communication */
 	.is_accelerated_mode = bios_is_accelerated_mode,
+	.get_vga_enabled_displays = bios_get_vga_enabled_displays,
 
 	.set_scratch_critical_state = bios_parser_set_scratch_critical_state,
 

drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c

@@ -1280,6 +1280,12 @@ static bool bios_parser_is_accelerated_mode(
 	return bios_is_accelerated_mode(dcb);
 }
 
+static uint32_t bios_parser_get_vga_enabled_displays(
+	struct dc_bios *bios)
+{
+	return bios_get_vga_enabled_displays(bios);
+}
+
 
 /**
  * bios_parser_set_scratch_critical_state
@@ -1800,6 +1806,7 @@ static const struct dc_vbios_funcs vbios_funcs = {
 
 
 	.is_accelerated_mode = bios_parser_is_accelerated_mode,
+	.get_vga_enabled_displays = bios_parser_get_vga_enabled_displays,
 
 	.set_scratch_critical_state = bios_parser_set_scratch_critical_state,
 

drivers/gpu/drm/amd/display/dc/bios/bios_parser_helper.c

@@ -78,5 +78,13 @@ void bios_set_scratch_critical_state(
 	REG_UPDATE(BIOS_SCRATCH_6, S6_CRITICAL_STATE, critial_state);
 }
 
+uint32_t bios_get_vga_enabled_displays(
+	struct dc_bios *bios)
+{
+	uint32_t active_disp = 1;
 
+	if (bios->regs->BIOS_SCRATCH_3) /*follow up with other asic, todo*/
+		active_disp = REG_READ(BIOS_SCRATCH_3) & 0XFFFF;
+	return active_disp;
+}
 

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

@@ -34,6 +34,7 @@ uint8_t *bios_get_image(struct dc_bios *bp, uint32_t offset,
 bool bios_is_accelerated_mode(struct dc_bios *bios);
 void bios_set_scratch_acc_mode_change(struct dc_bios *bios);
 void bios_set_scratch_critical_state(struct dc_bios *bios, bool state);
+uint32_t bios_get_vga_enabled_displays(struct dc_bios *bios);
 
 #define GET_IMAGE(type, offset) ((type *) bios_get_image(&bp->base, offset, sizeof(type)))
 

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

@@ -111,6 +111,8 @@ struct dc_vbios_funcs {
 		struct dc_bios *bios);
 	bool (*is_accelerated_mode)(
 		struct dc_bios *bios);
+	uint32_t (*get_vga_enabled_displays)(
+		struct dc_bios *bios);
 	void (*get_bios_event_info)(
 		struct dc_bios *bios,
 		struct bios_event_info *info);
@@ -199,6 +201,7 @@ struct dc_vbios_funcs {
 };
 
 struct bios_registers {
+	uint32_t BIOS_SCRATCH_3;
 	uint32_t BIOS_SCRATCH_6;
 };
 

drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c

@@ -1484,20 +1484,21 @@ static struct dc_link *get_link_for_edp_not_in_use(
  */
 void dce110_enable_accelerated_mode(struct dc *dc, struct dc_state *context)
 {
+	struct dc_bios *dcb = dc->ctx->dc_bios;
 	struct dc_link *edp_link_to_turnoff = get_link_for_edp_not_in_use(dc, context);
 
 	struct dc_link *edp_link = get_link_for_edp(dc);
-
-	if (edp_link)
-		/*we need turn off backlight before DP_blank and encoder powered down*/
+	if (dcb->funcs->get_vga_enabled_displays(dc->ctx->dc_bios) != 0) {
+		if (edp_link_to_turnoff) {
+			/*we need turn off backlight before DP_blank and encoder powered down, todo add optimization*/
 			dc->hwss.edp_backlight_control(edp_link, false);
-
+		}
+		/*resume from S3, no vbios posting, no need to power down again*/
 		power_down_all_hw_blocks(dc);
 		disable_vga_and_power_gate_all_controllers(dc);
-
 		if (edp_link_to_turnoff)
 			dc->hwss.edp_power_control(edp_link_to_turnoff, false);
-
+	}
 	bios_set_scratch_acc_mode_change(dc->ctx->dc_bios);
 }
 

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_resource.c

@@ -366,6 +366,7 @@ static const struct dcn_optc_mask tg_mask = {
 
 
 static const struct bios_registers bios_regs = {
+		NBIO_SR(BIOS_SCRATCH_3),
 		NBIO_SR(BIOS_SCRATCH_6)
 };