drm/amdgpu: check before checking pci bridge registers

commit e79d5c0870eedce94e5f5a2ffab30511e48fa144 upstream.

Make sure we are not the root device before attempting to
read the pcie bridge registers to check the pcie gen speeed.

Fixes a crash when the device is passed through to a VM.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/amd/amdgpu/cik.c b/drivers/gpu/drm/amd/amdgpu/cik.c
index 341c566818419317a0c3d16a3d5b738840e30b46..519fa515c4d86f57238b581c2125f4a009ed9f85 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/cik.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik.c
@@ -1565,6 +1565,9 @@ static void cik_pcie_gen3_enable(struct amdgpu_device *adev)
        int ret, i;
        u16 tmp16;
 
+       if (pci_is_root_bus(adev->pdev->bus))
+               return;
+
        if (amdgpu_pcie_gen2 == 0)
                return;
 

diff --git a/drivers/gpu/drm/amd/amdgpu/vi.c b/drivers/gpu/drm/amd/amdgpu/vi.c
index 4f58a1e18de68cebe47bd00c749dd7f1a6263ebb..9ffa56cebdbc36acbd5887097c30842b54b4cf0c 100644 (file)
--- a/drivers/gpu/drm/amd/amdgpu/vi.c
+++ b/drivers/gpu/drm/amd/amdgpu/vi.c
@@ -968,6 +968,9 @@ static void vi_pcie_gen3_enable(struct amdgpu_device *adev)
        u32 mask;
        int ret;
 
+       if (pci_is_root_bus(adev->pdev->bus))
+               return;
+
        if (amdgpu_pcie_gen2 == 0)
                return;