From 533c262797f7b52720d72fffdef38a5b7d1eab56 Mon Sep 17 00:00:00 2001
From: Dirk Gouders <dirk@gouders.net>
Date: Thu, 1 Oct 2020 21:55:25 +0200
Subject: drm/amdgpu: fix NULL pointer dereference for Renoir
Git-commit: 33eade2cd27a49cd858fd7b21be8447462afe859
Patch-mainline: v5.9
Alt-commit: 2ae78708047026397713a0e4af011bdd5d392e14
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

Commit c1cf79ca5ced46 ("drm/amdgpu: use IP discovery table for renoir")
introduced a NULL pointer dereference when booting with
amdgpu.discovery=0, because it removed the call of vega10_reg_base_init()
for that case.

Fix this by calling that funcion if amdgpu_discovery == 0 in addition to
the case that amdgpu_discovery_reg_base_init() failed.

Fixes: c1cf79ca5ced46 ("drm/amdgpu: use IP discovery table for renoir")
Signed-off-by: Dirk Gouders <dirk@gouders.net>
Cc: Hawking Zhang <Hawking.Zhang@amd.com>
Cc: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/soc15.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/soc15.c b/drivers/gpu/drm/amd/amdgpu/soc15.c
index 84d811b6e48b..c28ebf41530a 100644
--- a/drivers/gpu/drm/amd/amdgpu/soc15.c
+++ b/drivers/gpu/drm/amd/amdgpu/soc15.c
@@ -694,12 +694,12 @@ static void soc15_reg_base_init(struct amdgpu_device *adev)
 		 * it doesn't support SRIOV. */
 		if (amdgpu_discovery) {
 			r = amdgpu_discovery_reg_base_init(adev);
-			if (r) {
-				DRM_WARN("failed to init reg base from ip discovery table, "
-					 "fallback to legacy init method\n");
-				vega10_reg_base_init(adev);
-			}
+			if (r == 0)
+				break;
+			DRM_WARN("failed to init reg base from ip discovery table, "
+				 "fallback to legacy init method\n");
 		}
+		vega10_reg_base_init(adev);
 		break;
 	case CHIP_VEGA20:
 		vega20_reg_base_init(adev);
-- 
2.29.2