release/5.2.30/drm-amdgpu-dont-schedule-jobs-while-in-reset.patch

From 65e490f1b1adc19e2be9481feda07fbe2f6dc8ab Mon Sep 17 00:00:00 2001
From: Shirish S <shirish.s@amd.com>
Date: Wed, 30 Oct 2019 14:20:46 +0530
Subject: [PATCH] drm/amdgpu: dont schedule jobs while in reset
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commit f2efc6e60089c99c342a6b7da47f1037e06c4296 upstream.

[Why]

doing kthread_park()/unpark() from drm_sched_entity_fini
while GPU reset is in progress defeats all the purpose of
drm_sched_stop->kthread_park.
If drm_sched_entity_fini->kthread_unpark() happens AFTER
drm_sched_stop->kthread_park nothing prevents from another
(third) thread to keep submitting job to HW which will be
picked up by the unparked scheduler thread and try to submit
to HW but fail because the HW ring is deactivated.

[How]
grab the reset lock before calling drm_sched_entity_fini()

Signed-off-by: Shirish S <shirish.s@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
index 62298ae5c81c..18089208582a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ctx.c
@@ -598,8 +598,11 @@ void amdgpu_ctx_mgr_entity_fini(struct amdgpu_ctx_mgr *mgr)
 			continue;
 		}
 
-		for (i = 0; i < num_entities; i++)
+		for (i = 0; i < num_entities; i++) {
+			mutex_lock(&ctx->adev->lock_reset);
 			drm_sched_entity_fini(&ctx->entities[0][i].entity);
+			mutex_unlock(&ctx->adev->lock_reset);
+		}
 	}
 }
 
-- 
2.7.4