[PATCH AUTOSEL 5.4 061/459] drm/amdgpu/sriov: workaround on rev_id for Navi12 under sriov

Sasha Levin
2020-02-14T16:03:15Z

From: Tiecheng Zhou <Tiecheng.Zhou@amd.com>

[ Upstream commit df5e984c8bd414561c320d6cbbb66d53abf4c7e2 ]

guest vm gets 0xffffffff when reading RCC_DEV0_EPF0_STRAP0,
as a consequence, the rev_id and external_rev_id are wrong.

workaround it by hardcoding the rev_id to 0, which is the default value.

v2. add comment in the code

Signed-off-by: Tiecheng Zhou <Tiecheng.Zhou@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/nv.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/nv.c b/drivers/gpu/drm/amd/amdgpu/nv.c
index de9b995b65b1a..2d780820ba00e 100644
--- a/drivers/gpu/drm/amd/amdgpu/nv.c
+++ b/drivers/gpu/drm/amd/amdgpu/nv.c
@@ -660,6 +660,12 @@ static int nv_common_early_init(void *handle)
adev->pg_flags = AMD_PG_SUPPORT_VCN |
AMD_PG_SUPPORT_VCN_DPG |
AMD_PG_SUPPORT_ATHUB;
+ /* guest vm gets 0xffffffff when reading RCC_DEV0_EPF0_STRAP0,
+ * as a consequence, the rev_id and external_rev_id are wrong.
+ * workaround it by hardcoding rev_id to 0 (default value).
+ */
+ if (amdgpu_sriov_vf(adev))
+ adev->rev_id = 0;
adev->external_rev_id = adev->rev_id + 0xa;
break;