[PATCH 8/9] drm/amdgpu: Forbid runtime pm on driver unload

[Lukas Wunner]

The PCI core calls pm_runtime_forbid() on device probe in pci_pm_init(),
making this the default state when amdgpu is loaded.
amdgpu_driver_load_kms() therefore calls pm_runtime_allow(), but there's
no pm_runtime_forbid() in amdgpu_driver_unload_kms() to balance it. Add
it so that we leave the device in the same state that we found it.

This isn't a bug, it's just good housekeeping. When amdgpu is first
loaded with runpm=1, then unloaded and loaded again with runpm=0,
pm_runtime_forbid() will be called from amdgpu_pmops_runtime_idle() or
amdgpu_pmops_runtime_suspend(), so the behaviour is correct. If there
ever is a third party driver for AMD cards, this commit avoids that it
has to clean up behind amdgpu.

Signed-off-by: Lukas Wunner <lukas at wunner.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index 0db692e..38a28d1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -62,6 +62,7 @@ int amdgpu_driver_unload_kms(struct drm_device *dev)
 
 	if (amdgpu_device_is_px(dev)) {
 		pm_runtime_get_sync(dev->dev);
+		pm_runtime_forbid(dev->dev);
 	}
 
 	amdgpu_amdkfd_device_fini(adev);
-- 
2.8.1