drm/amdgpu: Don't register Thunderbolt eGPU with vga_switcheroo

An external Thunderbolt GPU can neither drive the laptop's panel nor be
powered off by the platform, so there's no point in registering it with
vga_switcheroo.  In fact, when the external GPU is runtime suspended,
vga_switcheroo will cut power to the internal discrete GPU, resulting in
a lockup.  Moreover AMD's Windows driver special-cases Thunderbolt as
well.

Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: http://patchwork.freedesktop.org/patch/msgid/701a8e89ce8ac39734736ab779558b6a4042a19e.1489145162.git.lukas@wunner.de

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 61d94c745672..2f3b236721c9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -103,7 +103,8 @@ int amdgpu_driver_load_kms(struct drm_device *dev, unsigned long flags)
             amdgpu_has_atpx() &&
             (amdgpu_is_atpx_hybrid() ||
              amdgpu_has_atpx_dgpu_power_cntl()) &&
-            ((flags & AMD_IS_APU) == 0))
+            ((flags & AMD_IS_APU) == 0) &&
+            !pci_is_thunderbolt_attached(dev->pdev))
                 flags |= AMD_IS_PX;
 
         /* amdgpu_device_init should report only fatal error