From: Alex Deucher <alexander.deucher@amd.com>
Date: Thu, 10 May 2018 15:15:12 -0500
Subject: drm/amdgpu/gmc9: disable partial wr rmw if ECC is not enabled
Git-commit: e1d1a7729a62d7b79fb2ab4ac3bc6fc0ebfb6db9
Patch-mainline: v4.18-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

The vbios mistakenly sets this bit on some boards without ECC.
This can lead to reduced performance in some workloads.  Disable
the bit if the board does not have ECC.

Reviewed-by: Hawking Zhang <Hawking.Zhang@amd.com>
Reviewed-by: Junwei Zhang <Jerry.Zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c |    1 +
 1 file changed, 1 insertion(+)

--- a/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c
@@ -675,6 +675,7 @@ static int gmc_v9_0_late_init(void *hand
 			DRM_INFO("ECC is active.\n");
 		} else if (r == 0) {
 			DRM_INFO("ECC is not present.\n");
+			adev->df_funcs->enable_ecc_force_par_wr_rmw(adev, false);
 		} else {
 			DRM_ERROR("gmc_v9_0_ecc_available() failed. r: %d\n", r);
 			return r;