[PATCH] drm/amdgpu: disable cstate properly for driver reloading scenario

[Evan Quan]

Gpu reset might be needed during driver reloading. To guard that(gpu
reset) work, df cstate needs to be disabled properly.

Signed-off-by: Evan Quan <evan.quan at amd.com>
Change-Id: I5c074c265c0b08a67b6934ae1ad9aa3fed245461
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
index 51bbeaa1f311..3c854461ef32 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
@@ -2816,6 +2816,15 @@ static int amdgpu_device_ip_fini_early(struct amdgpu_device *adev)
 	amdgpu_device_set_pg_state(adev, AMD_PG_STATE_UNGATE);
 	amdgpu_device_set_cg_state(adev, AMD_CG_STATE_UNGATE);
 
+	/*
+	 * Get df cstate disabled properly on driver unloading.
+	 * Since on the succeeding driver reloading, gpu reset might
+	 * be required. And cstate disabled is a prerequisite for
+	 * that(gpu reset).
+	 */
+	if (amdgpu_dpm_set_df_cstate(adev, DF_CSTATE_DISALLOW))
+		dev_warn(adev->dev, "Failed to disallow df cstate");
+
 	amdgpu_amdkfd_suspend(adev, false);
 
 	/* Workaroud for ASICs need to disable SMC first */
-- 
2.34.1