From d6d7f73fc2c4a779556d8c0520f0c90d77e871e7 Mon Sep 17 00:00:00 2001 From: Andrey Grodzovsky Date: Wed, 6 Nov 2019 12:36:29 -0500 Subject: [PATCH] drm/amdgpu: Avoid accidental thread reactivation. MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Problem: During GPU reset we call the GPU scheduler to suspend it's thread, those two functions in amdgpu also suspend and resume the sceduler for their needs but this can collide with GPU reset in progress and accidently restart a suspended thread before time. Fix: Serialize with GPU reset. Signed-off-by: Andrey Grodzovsky Reviewed-by: Christian König Signed-off-by: Alex Deucher --- drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c index 693f17e787914..8e6726e0d035f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c @@ -859,6 +859,9 @@ static int amdgpu_debugfs_test_ib(struct seq_file *m, void *data) struct amdgpu_device *adev = dev->dev_private; int r = 0, i; + /* Avoid accidently unparking the sched thread during GPU reset */ + mutex_lock(&adev->lock_reset); + /* hold on the scheduler */ for (i = 0; i < AMDGPU_MAX_RINGS; i++) { struct amdgpu_ring *ring = adev->rings[i]; @@ -884,6 +887,8 @@ static int amdgpu_debugfs_test_ib(struct seq_file *m, void *data) kthread_unpark(ring->sched.thread); } + mutex_unlock(&adev->lock_reset); + return 0; } @@ -1036,6 +1041,9 @@ static int amdgpu_debugfs_ib_preempt(void *data, u64 val) if (!fences) return -ENOMEM; + /* Avoid accidently unparking the sched thread during GPU reset */ + mutex_lock(&adev->lock_reset); + /* stop the scheduler */ kthread_park(ring->sched.thread); @@ -1075,6 +1083,8 @@ failure: /* restart the scheduler */ kthread_unpark(ring->sched.thread); + mutex_unlock(&adev->lock_reset); + ttm_bo_unlock_delayed_workqueue(&adev->mman.bdev, resched); kfree(fences); -- 2.39.5