[PATCH 1/2] drm/sched: Set error to s_fence if HW job submission failed.

[Grodzovsky, Andrey]

On 10/25/19 11:55 AM, Koenig, Christian wrote:
> Am 25.10.19 um 16:57 schrieb Grodzovsky, Andrey:
>> On 10/25/19 4:44 AM, Christian König wrote:
>>> Am 24.10.19 um 21:57 schrieb Andrey Grodzovsky:
>>>> Problem:
>>>> When run_job fails and HW fence returned is NULL we still signal
>>>> the s_fence to avoid hangs but the user has no way of knowing if
>>>> the actual HW job was ran and finished.
>>>>
>>>> Fix:
>>>> Allow .run_job implementations to return ERR_PTR in the fence pointer
>>>> returned and then set this error for s_fence->finished fence so whoever
>>>> wait on this fence can inspect the signaled fence for an error.
>>>>
>>>> Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky at amd.com>
>>>> ---
>>>>     drivers/gpu/drm/scheduler/sched_main.c | 19 ++++++++++++++++---
>>>>     1 file changed, 16 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/scheduler/sched_main.c
>>>> b/drivers/gpu/drm/scheduler/sched_main.c
>>>> index 9a0ee74..f39b97e 100644
>>>> --- a/drivers/gpu/drm/scheduler/sched_main.c
>>>> +++ b/drivers/gpu/drm/scheduler/sched_main.c
>>>> @@ -479,6 +479,7 @@ void drm_sched_resubmit_jobs(struct
>>>> drm_gpu_scheduler *sched)
>>>>         struct drm_sched_job *s_job, *tmp;
>>>>         uint64_t guilty_context;
>>>>         bool found_guilty = false;
>>>> +    struct dma_fence *fence;
>>>>           list_for_each_entry_safe(s_job, tmp,
>>>> &sched->ring_mirror_list, node) {
>>>>             struct drm_sched_fence *s_fence = s_job->s_fence;
>>>> @@ -492,7 +493,16 @@ void drm_sched_resubmit_jobs(struct
>>>> drm_gpu_scheduler *sched)
>>>>                 dma_fence_set_error(&s_fence->finished, -ECANCELED);
>>>>               dma_fence_put(s_job->s_fence->parent);
>>>> -        s_job->s_fence->parent = sched->ops->run_job(s_job);
>>>> +        fence = sched->ops->run_job(s_job);
>>>> +
>>>> +        if (IS_ERR_OR_NULL(fence)) {
>>>> +            s_job->s_fence->parent = NULL;
>>>> +            dma_fence_set_error(&s_fence->finished, PTR_ERR(fence));
>>>> +        } else {
>>>> +            s_job->s_fence->parent = fence;
>>>> +        }
>>>> +
>>>> +
>>> Maybe time for a drm_sched_run_job() function which does that
>>> handling? And why don't we need to install the callback here?
>> What code do you want to put in drm_sched_run_job ?
>>
>> We reinstall the callback later in drm_sched_start,
>> drm_sched_resubmit_jobs is conditional on whether the guilty fence did
>> signal by this time or not and so the split of the logic into
>> drm_sched_start and drm_sched_resubmit_jobs.
> Ah, yes of course. In this case the patch is Reviewed-by: Christian
> König <christian.koenig at amd.com>.
>
> Regards,
> Christian.


Thanks, there is also 2/2 patch for amdgpu, please take a look.

Andrey


>
>> Andrey
>>
>>
>>> Apart from that looks good to me,
>>> Christian.
>>>
>>>>         }
>>>>     }
>>>>     EXPORT_SYMBOL(drm_sched_resubmit_jobs);
>>>> @@ -720,7 +730,7 @@ static int drm_sched_main(void *param)
>>>>             fence = sched->ops->run_job(sched_job);
>>>>             drm_sched_fence_scheduled(s_fence);
>>>>     -        if (fence) {
>>>> +        if (!IS_ERR_OR_NULL(fence)) {
>>>>                 s_fence->parent = dma_fence_get(fence);
>>>>                 r = dma_fence_add_callback(fence, &sched_job->cb,
>>>>                                drm_sched_process_job);
>>>> @@ -730,8 +740,11 @@ static int drm_sched_main(void *param)
>>>>                     DRM_ERROR("fence add callback failed (%d)\n",
>>>>                           r);
>>>>                 dma_fence_put(fence);
>>>> -        } else
>>>> +        } else {
>>>> +
>>>> +            dma_fence_set_error(&s_fence->finished, PTR_ERR(fence));
>>>>                 drm_sched_process_job(NULL, &sched_job->cb);
>>>> +        }
>>>>               wake_up(&sched->job_scheduled);
>>>>         }