From: =?UTF-8?q?Nicolai=20H=C3=A4hnle?= <nicolai.haehnle@amd.com>
Date: Thu, 28 Sep 2017 11:51:32 +0200
Subject: drm/amd/sched: NULL out the s_fence field after run_job
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Git-commit: 29d253553559dba919315be847f4f2cce29edd42
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166

amd_sched_process_job drops the fence reference, so NULL out the s_fence
field before adding it as a callback to guard against accidentally using
s_fence after it may have be freed.

v2: add a clarifying comment

Signed-off-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Andres Rodriguez <andresx7@gmail.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
 drivers/gpu/drm/amd/scheduler/gpu_scheduler.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
+++ b/drivers/gpu/drm/amd/scheduler/gpu_scheduler.c
@@ -611,6 +611,10 @@ static int amd_sched_main(void *param)
 
 		fence = sched->ops->run_job(sched_job);
 		amd_sched_fence_scheduled(s_fence);
+
+		/* amd_sched_process_job drops the job's reference of the fence. */
+		sched_job->s_fence = NULL;
+
 		if (fence) {
 			s_fence->parent = dma_fence_get(fence);
 			r = dma_fence_add_callback(fence, &s_fence->cb,