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
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 61d94c7..2f3b236 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