[PATCH] drm/amdgpu: fix a race in GPU reset with IB test

[Christian König]

Am 28.05.19 um 21:29 schrieb Alex Deucher:
> Split late_init into two functions, one (do_late_init) which
> just does the hw init, and late_init which calls do_late_init
> and schedules the IB test work.  Call do_late_init in
> the GPU reset code to run the init code, but not schedule
> the IB test code.  The IB test code is called directly
> in the gpu reset code so no need to run the IB tests
> in a separate work thread.  If we do, we end up racing.

I already had the suspicion that we do something wrong in the reset path 
with this.

But I don't really like the naming. How about we call the late_init_work 
delayed_init_work instead and explicitly schedule it from 
amdgpu_device_init() ?

Christian.

>
> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 43 +++++++++++++---------
>   1 file changed, 26 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> index 7a8c2201cd04..6b90840307dc 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c
> @@ -1869,19 +1869,7 @@ static int amdgpu_device_set_pg_state(struct amdgpu_device *adev, enum amd_power
>   	return 0;
>   }
>   
> -/**
> - * amdgpu_device_ip_late_init - run late init for hardware IPs
> - *
> - * @adev: amdgpu_device pointer
> - *
> - * Late initialization pass for hardware IPs.  The list of all the hardware
> - * IPs that make up the asic is walked and the late_init callbacks are run.
> - * late_init covers any special initialization that an IP requires
> - * after all of the have been initialized or something that needs to happen
> - * late in the init process.
> - * Returns 0 on success, negative error code on failure.
> - */
> -static int amdgpu_device_ip_late_init(struct amdgpu_device *adev)
> +static int amdgpu_device_do_ip_late_init(struct amdgpu_device *adev)
>   {
>   	int i = 0, r;
>   
> @@ -1902,14 +1890,35 @@ static int amdgpu_device_ip_late_init(struct amdgpu_device *adev)
>   	amdgpu_device_set_cg_state(adev, AMD_CG_STATE_GATE);
>   	amdgpu_device_set_pg_state(adev, AMD_PG_STATE_GATE);
>   
> -	queue_delayed_work(system_wq, &adev->late_init_work,
> -			   msecs_to_jiffies(AMDGPU_RESUME_MS));
> -
>   	amdgpu_device_fill_reset_magic(adev);
>   
>   	return 0;
>   }
>   
> +/**
> + * amdgpu_device_ip_late_init - run late init for hardware IPs
> + *
> + * @adev: amdgpu_device pointer
> + *
> + * Late initialization pass for hardware IPs.  The list of all the hardware
> + * IPs that make up the asic is walked and the late_init callbacks are run.
> + * late_init covers any special initialization that an IP requires
> + * after all of the have been initialized or something that needs to happen
> + * late in the init process.
> + * Returns 0 on success, negative error code on failure.
> + */
> +static int amdgpu_device_ip_late_init(struct amdgpu_device *adev)
> +{
> +	int r;
> +
> +	r = amdgpu_device_do_ip_late_init(adev);
> +
> +	queue_delayed_work(system_wq, &adev->late_init_work,
> +			   msecs_to_jiffies(AMDGPU_RESUME_MS));
> +
> +	return r;
> +}
> +
>   /**
>    * amdgpu_device_ip_fini - run fini for hardware IPs
>    *
> @@ -3502,7 +3511,7 @@ static int amdgpu_do_asic_reset(struct amdgpu_hive_info *hive,
>   				if (vram_lost)
>   					amdgpu_device_fill_reset_magic(tmp_adev);
>   
> -				r = amdgpu_device_ip_late_init(tmp_adev);
> +				r = amdgpu_device_do_ip_late_init(tmp_adev);
>   				if (r)
>   					goto out;
>