[PATCH] amdgpu: disable GPU reset if amdgpu.lockup_timeout=0

[Christian König]

Am 11.12.2017 um 22:29 schrieb Marek Olšák:
> From: Marek Olšák <marek.olsak at amd.com>
>
> Signed-off-by: Marek Olšák <marek.olsak at amd.com>
> ---
>
> Is this really correct? I have no easy way to test it.

It's a step in the right direction, but I would rather vote for 
something else:

Instead of disabling the timeout by default we only disable the GPU 
reset/recovery.

The idea is to add a new parameter amdgpu_gpu_recovery which makes 
amdgpu_gpu_recover only prints out an error and doesn't touch the GPU at 
all (on bare metal systems).

Then we finally set the amdgpu_lockup_timeout to a non zero value by 
default.

Andrey could you take care of this when you have time?

Thanks,
Christian.

>
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 8d03baa..56c41cf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -3018,20 +3018,24 @@ static int amdgpu_reset_sriov(struct amdgpu_device *adev, uint64_t *reset_flags,
>    *
>    * Attempt to reset the GPU if it has hung (all asics).
>    * Returns 0 for success or an error on failure.
>    */
>   int amdgpu_gpu_recover(struct amdgpu_device *adev, struct amdgpu_job *job)
>   {
>   	struct drm_atomic_state *state = NULL;
>   	uint64_t reset_flags = 0;
>   	int i, r, resched;
>   
> +	/* amdgpu.lockup_timeout=0 disables GPU reset. */
> +	if (amdgpu_lockup_timeout == 0)
> +		return 0;
> +
>   	if (!amdgpu_check_soft_reset(adev)) {
>   		DRM_INFO("No hardware hang detected. Did some blocks stall?\n");
>   		return 0;
>   	}
>   
>   	dev_info(adev->dev, "GPU reset begin!\n");
>   
>   	mutex_lock(&adev->lock_reset);
>   	atomic_inc(&adev->gpu_reset_counter);
>   	adev->in_gpu_reset = 1;