drm/sched: revert "fix timeout handling v2" v2

{

	struct drm_gpu_scheduler *sched;

	struct drm_sched_job *job;

	int r;

	sched = container_of(work, struct drm_gpu_scheduler, work_tdr.work);

	spin_lock(&sched->job_list_lock);

	list_for_each_entry_reverse(job, &sched->ring_mirror_list, node) {

		struct drm_sched_fence *fence = job->s_fence;

		if (!dma_fence_remove_callback(fence->parent, &fence->cb))

			goto already_signaled;

	}

	job = list_first_entry_or_null(&sched->ring_mirror_list,

				       struct drm_sched_job, node);

	spin_unlock(&sched->job_list_lock);

	if (job)

		sched->ops->timedout_job(job);

		job->sched->ops->timedout_job(job);

	spin_lock(&sched->job_list_lock);

	list_for_each_entry(job, &sched->ring_mirror_list, node) {

		struct drm_sched_fence *fence = job->s_fence;

		if (!fence->parent || !list_empty(&fence->cb.node))

			continue;

		r = dma_fence_add_callback(fence->parent, &fence->cb,

					   drm_sched_process_job);

		if (r)

			drm_sched_process_job(fence->parent, &fence->cb);

already_signaled:

		;

	}

	drm_sched_start_timeout(sched);

	spin_unlock(&sched->job_list_lock);

}