[PATCH 1/3] drm/amdgpu: wait for all rings to drain before runtime suspending

[Andrey Grodzovsky]

Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>

Andrey

On 12/16/19 12:18 PM, Alex Deucher wrote:
> Add a safety check to runtime suspend to make sure all outstanding
> fences have signaled before we suspend.  Doesn't fix any known issue.
>
> We already do this via the fence driver suspend function, but we
> just force completion rather than bailing.  This bails on runtime
> suspend so we can try again later once the fences are signaled to
> avoid missing any outstanding work.
>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c | 12 +++++++++++-
>   1 file changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> index d1e9946ac218..61dc26515c7e 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> @@ -1214,13 +1214,23 @@ static int amdgpu_pmops_runtime_suspend(struct device *dev)
>   	struct pci_dev *pdev = to_pci_dev(dev);
>   	struct drm_device *drm_dev = pci_get_drvdata(pdev);
>   	struct amdgpu_device *adev = drm_dev->dev_private;
> -	int ret;
> +	int ret, i;
>   
>   	if (!adev->runpm) {
>   		pm_runtime_forbid(dev);
>   		return -EBUSY;
>   	}
>   
> +	/* wait for all rings to drain before suspending */
> +	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
> +		struct amdgpu_ring *ring = adev->rings[i];
> +		if (ring && ring->sched.ready) {
> +			ret = amdgpu_fence_wait_empty(ring);
> +			if (ret)
> +				return -EBUSY;
> +		}
> +	}
> +
>   	if (amdgpu_device_supports_boco(drm_dev))
>   		drm_dev->switch_power_state = DRM_SWITCH_POWER_CHANGING;
>   	drm_kms_helper_poll_disable(drm_dev);