drm/scheduler: signal scheduled fence when kill job

JIRA: https://issues.redhat.com/browse/RHEL-75958

commit aa382a8b6ed483e9812d0e63b6d1bdcba0186f29
Author: Lin.Cao <lincao12@amd.com>
Date:   Thu May 15 10:07:13 2025 +0800

    drm/scheduler: signal scheduled fence when kill job

    [ Upstream commit 471db2c ]

    When an entity from application B is killed, drm_sched_entity_kill()
    removes all jobs belonging to that entity through
    drm_sched_entity_kill_jobs_work(). If application A's job depends on a
    scheduled fence from application B's job, and that fence is not properly
    signaled during the killing process, application A's dependency cannot be
    cleared.

    This leads to application A hanging indefinitely while waiting for a
    dependency that will never be resolved. Fix this issue by ensuring that
    scheduled fences are properly signaled when an entity is killed, allowing
    dependent applications to continue execution.

    Signed-off-by: Lin.Cao <lincao12@amd.com>
    Reviewed-by: Philipp Stanner <phasta@kernel.org>
    Signed-off-by: Christian König <christian.koenig@amd.com>
    Link: https://lore.kernel.org/r/20250515020713.1110476-1-lincao12@amd.com
    Signed-off-by: Sasha Levin <sashal@kernel.org>

Signed-off-by: José Expósito <jexposit@redhat.com>

Author: jexposit

drivers/gpu/drm/scheduler/sched_entity.c

@@ -176,6 +176,7 @@ static void drm_sched_entity_kill_jobs_work(struct work_struct *wrk)
 {
 	struct drm_sched_job *job = container_of(wrk, typeof(*job), work);
 
+	drm_sched_fence_scheduled(job->s_fence, NULL);
 	drm_sched_fence_finished(job->s_fence, -ESRCH);
 	WARN_ON(job->s_fence->parent);
 	job->sched->ops->free_job(job);