From: Hersen Wu <hersenxs.wu@amd.com>
Date: Thu, 25 May 2017 10:55:54 -0400
Subject: drm/amd/display: create_links bug with empty DDI slot
Git-commit: e4bf0a0eed7e0e3bb7f0be2788cf0a5ecc16b068
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Reviewed-by: Hersen Wu <hersenxs.wu@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c |    7 ++++---
 drivers/gpu/drm/amd/display/dc/core/dc.c           |    3 +--
 2 files changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c
+++ b/drivers/gpu/drm/amd/display/dc/bios/bios_parser2.c
@@ -410,6 +410,9 @@ enum generic_id generic_id_from_bios_obj
 	return id;
 }
 
+/* BIOS oject table displaypath is per connector.
+ * There is extra path not for connector. BIOS fill its encoderid as 0
+ */
 static uint8_t bios_parser_get_connectors_number(struct dc_bios *dcb)
 {
 	struct bios_parser *bp = BP_FROM_DCB(dcb);
@@ -417,9 +420,7 @@ static uint8_t bios_parser_get_connector
 	unsigned int i;
 
 	for (i = 0; i < bp->object_info_tbl.v1_4->number_of_path; i++) {
-		if (bp->object_info_tbl.v1_4->display_path[i].encoderobjid != 0
-				&&
-		bp->object_info_tbl.v1_4->display_path[i].display_objid != 0)
+		if (bp->object_info_tbl.v1_4->display_path[i].encoderobjid != 0)
 			count++;
 	}
 	return count;
--- a/drivers/gpu/drm/amd/display/dc/core/dc.c
+++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
@@ -97,6 +97,7 @@ static bool create_links(
 		struct core_link *link;
 
 		link_init_params.ctx = dc->ctx;
+		/* next BIOS object table connector */
 		link_init_params.connector_index = i;
 		link_init_params.link_index = dc->link_count;
 		link_init_params.dc = dc;
@@ -106,8 +107,6 @@ static bool create_links(
 			dc->links[dc->link_count] = link;
 			link->dc = dc;
 			++dc->link_count;
-		} else {
-			dm_error("DC: failed to create link!\n");
 		}
 	}