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

[Koenig, Christian]

Am 25.10.19 um 17:56 schrieb 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.

Seen that, feel free to add my rb as well.

Christian.

>
> 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);
>>>>>          }