[PATCH] drm/amdgpu: Fix a race of IB test

[xinhui pan]

Direct IB submission should be exclusive. So use write lock.

Signed-off-by: xinhui pan <xinhui.pan at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
index 19323b4cce7b..acbe02928791 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_debugfs.c
@@ -1358,10 +1358,15 @@ static int amdgpu_debugfs_test_ib_show(struct seq_file *m, void *unused)
 	}
 
 	/* Avoid accidently unparking the sched thread during GPU reset */
-	r = down_read_killable(&adev->reset_sem);
+	r = down_write_killable(&adev->reset_sem);
 	if (r)
 		return r;
 
+	/* Avoid concurrently IB test but not cancel it as I don't know whether we
+	 * would add more code in the delayed init work.
+	 */
+	flush_delayed_work(&adev->delayed_init_work);
+
 	/* hold on the scheduler */
 	for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
 		struct amdgpu_ring *ring = adev->rings[i];
@@ -1387,7 +1392,7 @@ static int amdgpu_debugfs_test_ib_show(struct seq_file *m, void *unused)
 		kthread_unpark(ring->sched.thread);
 	}
 
-	up_read(&adev->reset_sem);
+	up_write(&adev->reset_sem);
 
 	pm_runtime_mark_last_busy(dev->dev);
 	pm_runtime_put_autosuspend(dev->dev);
-- 
2.25.1