drm/amd/display: Skip backlight control delay on external powered links

[Why]
When an eDP panel is powered externally from a different GPU, we can avoid
waiting for hardware sequencing delays when switching the backlight on/off
as the display backlight is no longer powered by the original source.

[How]
This commit extends the 'link_powered_externally' variable to allow
bypassing hardware delays for additional backlight commands and force the
backlight on/off when a link is powered by another GPU.
Tested-by: Daniel Wheeler <Daniel.Wheeler@amd.com>
Reviewed-by: Felipe Clark <felipe.clark@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Tony Tascioglu <tony.tascioglu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -1698,14 +1698,14 @@ static enum bp_result bios_parser_enable_lvtma_control(
 	struct dc_bios *dcb,
 	uint8_t uc_pwr_on,
 	uint8_t panel_instance,
-	uint8_t bypass_powerdown_wait)
+	uint8_t bypass_panel_control_wait)
 {
 	struct bios_parser *bp = BP_FROM_DCB(dcb);
 
 	if (!bp->cmd_tbl.enable_lvtma_control)
 		return BP_RESULT_FAILURE;
 
-	return bp->cmd_tbl.enable_lvtma_control(bp, uc_pwr_on, panel_instance, bypass_powerdown_wait);
+	return bp->cmd_tbl.enable_lvtma_control(bp, uc_pwr_on, panel_instance, bypass_panel_control_wait);
 }
 
 static bool bios_parser_is_accelerated_mode(

drivers/gpu/drm/amd/display/dc/bios/command_table2.c

@@ -987,7 +987,7 @@ static enum bp_result enable_lvtma_control(
 	struct bios_parser *bp,
 	uint8_t uc_pwr_on,
 	uint8_t panel_instance,
-	uint8_t bypass_powerdown_wait);
+	uint8_t bypass_panel_control_wait);
 
 static void init_enable_lvtma_control(struct bios_parser *bp)
 {
@@ -1000,7 +1000,7 @@ static void enable_lvtma_control_dmcub(
 	struct dc_dmub_srv *dmcub,
 	uint8_t uc_pwr_on,
 	uint8_t panel_instance,
-	uint8_t bypass_powerdown_wait)
+	uint8_t bypass_panel_control_wait)
 {
 
 	union dmub_rb_cmd cmd;
@@ -1014,8 +1014,8 @@ static void enable_lvtma_control_dmcub(
 			uc_pwr_on;
 	cmd.lvtma_control.data.panel_inst =
 			panel_instance;
-	cmd.lvtma_control.data.bypass_powerdown_wait =
-			bypass_powerdown_wait;
+	cmd.lvtma_control.data.bypass_panel_control_wait =
+			bypass_panel_control_wait;
 	dc_dmub_srv_cmd_queue(dmcub, &cmd);
 	dc_dmub_srv_cmd_execute(dmcub);
 	dc_dmub_srv_wait_idle(dmcub);
@@ -1026,7 +1026,7 @@ static enum bp_result enable_lvtma_control(
 	struct bios_parser *bp,
 	uint8_t uc_pwr_on,
 	uint8_t panel_instance,
-	uint8_t bypass_powerdown_wait)
+	uint8_t bypass_panel_control_wait)
 {
 	enum bp_result result = BP_RESULT_FAILURE;
 
@@ -1035,7 +1035,7 @@ static enum bp_result enable_lvtma_control(
 		enable_lvtma_control_dmcub(bp->base.ctx->dmub_srv,
 				uc_pwr_on,
 				panel_instance,
-				bypass_powerdown_wait);
+				bypass_panel_control_wait);
 		return BP_RESULT_OK;
 	}
 	return result;

drivers/gpu/drm/amd/display/dc/bios/command_table2.h

@@ -97,7 +97,7 @@ struct cmd_tbl {
 	enum bp_result (*enable_lvtma_control)(struct bios_parser *bp,
 			uint8_t uc_pwr_on,
 			uint8_t panel_instance,
-			uint8_t bypass_powerdown_wait);
+			uint8_t bypass_panel_control_wait);
 };
 
 void dal_firmware_parser_init_cmd_tbl(struct bios_parser *bp);

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

@@ -141,7 +141,7 @@ struct dc_vbios_funcs {
 		struct dc_bios *bios,
 		uint8_t uc_pwr_on,
 		uint8_t panel_instance,
-		uint8_t bypass_powerdown_wait);
+		uint8_t bypass_panel_control_wait);
 
 	enum bp_result (*get_soc_bb_info)(
 		struct dc_bios *dcb,

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

@@ -943,7 +943,6 @@ void dce110_edp_wait_for_T12(
 			msleep(t12_duration - time_since_edp_poweroff_ms);
 	}
 }
-
 /*todo: cloned in stream enc, fix*/
 /*
  * @brief
@@ -1022,16 +1021,20 @@ void dce110_edp_backlight_control(
 			DC_LOG_DC("edp_receiver_ready_T7 skipped\n");
 	}
 
+	/* Setting link_powered_externally will bypass delays in the backlight
+	 * as they are not required if the link is being powered by a different
+	 * source.
+	 */
 	if (ctx->dc->ctx->dmub_srv &&
 			ctx->dc->debug.dmub_command_table) {
 		if (cntl.action == TRANSMITTER_CONTROL_BACKLIGHT_ON)
 			ctx->dc_bios->funcs->enable_lvtma_control(ctx->dc_bios,
 					LVTMA_CONTROL_LCD_BLON,
-					panel_instance, 0);
+					panel_instance, link->link_powered_externally);
 		else
 			ctx->dc_bios->funcs->enable_lvtma_control(ctx->dc_bios,
 					LVTMA_CONTROL_LCD_BLOFF,
-					panel_instance, 0);
+					panel_instance, link->link_powered_externally);
 	}
 
 	link_transmitter_control(ctx->dc_bios, &cntl);

drivers/gpu/drm/amd/display/dmub/inc/dmub_cmd.h

@@ -3111,7 +3111,7 @@ struct dmub_rb_cmd_panel_cntl {
  */
 struct dmub_cmd_lvtma_control_data {
 	uint8_t uc_pwr_action; /**< LVTMA_ACTION */
-	uint8_t bypass_powerdown_wait;
+	uint8_t bypass_panel_control_wait;
 	uint8_t reserved_0[2];
 	uint8_t panel_inst; /**< LVTMA control instance */
 	uint8_t reserved_1[3]; /**< For future use */