[PATCH] drm/amdgpu: fix a GPU hang issue when remove device

[Dennis Li]

When GFXOFF is enabled and GPU is idle, driver will fail to access some
registers. Therefore disable GFXOFF before unload device.

amdgpu 0000:03:00.0: amdgpu: amdgpu: finishing device.
amdgpu: cp queue pipe 4 queue 0 preemption failed
amdgpu 0000:03:00.0: amdgpu: failed to write reg 2890 wait reg 28a2
amdgpu 0000:03:00.0: amdgpu: failed to write reg 1a6f4 wait reg 1a706
amdgpu 0000:03:00.0: amdgpu: failed to write reg 2890 wait reg 28a2
amdgpu 0000:03:00.0: amdgpu: failed to write reg 1a6f4 wait reg 1a706

Signed-off-by: Dennis Li <Dennis.Li at amd.com>
Change-Id: I42431f5d0bf54909e1df888a0d72fc009d8e196c

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index e365c4fdcfe3..47d1291d5053 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -83,6 +83,8 @@ void amdgpu_driver_unload_kms(struct drm_device *dev)
 	if (adev == NULL)
 		return;
 
+	amdgpu_gfx_off_ctrl(adev, false);
+
 	amdgpu_unregister_gpu_instance(adev);
 
 	if (adev->rmmio == NULL)
-- 
2.17.1