From: "Leo (Sunpeng) Li" <sunpeng.li@amd.com>
Date: Fri, 16 Jun 2017 15:59:17 -0400
Subject: drm/amd/display: Workaround IGT multiplane restriction
Git-commit: 92f3ac403d132400b7147bb4262fea4ad254aa3d
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

IGT currently does not properly commit changes on planes with multiple
possible CRTC's. Set one valid CRTC for each plane for now, plus one
underlay plane on Carizzo and Stoney that is valid for all CRTCs.

Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-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/amdgpu_dm/amdgpu_dm.c |   14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -1189,6 +1189,7 @@ int amdgpu_dm_initialize_drm_device(stru
 	struct amdgpu_encoder *aencoder = NULL;
 	struct amdgpu_mode_info *mode_info = &adev->mode_info;
 	uint32_t link_cnt;
+	unsigned long possible_crtcs;
 
 	link_cnt = dm->dc->caps.max_links;
 	if (amdgpu_dm_mode_config_init(dm->adev)) {
@@ -1204,7 +1205,18 @@ int amdgpu_dm_initialize_drm_device(stru
 			goto fail_free_planes;
 		}
 		mode_info->planes[i]->base.type = mode_info->plane_type[i];
-		if (amdgpu_dm_plane_init(dm, mode_info->planes[i], 0xff)) {
+
+		/*
+		 * HACK: IGT tests expect that each plane can only have one
+		 * one possible CRTC. For now, set one CRTC for each
+		 * plane that is not an underlay, but still allow multiple
+		 * CRTCs for underlay planes.
+		 */
+		possible_crtcs = 1 << i;
+		if (i >= dm->dc->caps.max_streams)
+			possible_crtcs = 0xff;
+
+		if (amdgpu_dm_plane_init(dm, mode_info->planes[i], possible_crtcs)) {
 			DRM_ERROR("KMS: Failed to initialize plane\n");
 			goto fail_free_planes;
 		}