[PATCH 1/1] drm/amdgpu: fix NULL pointer dereference for Renoir

From: Dirk Gouders
Date: Thu Oct 01 2020 - 16:02:09 EST


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@xxxxxxxxxxx>
Cc: Hawking Zhang <Hawking.Zhang@xxxxxxx>
Cc: Evan Quan <evan.quan@xxxxxxx>
---
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..f8cb62b326d6 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);
--
2.26.2