[PATCH v6 13/16] drm/amdgpu: Fix hang on device removal.

[Andrey Grodzovsky]

If removing while commands in flight you cannot wait to flush the
HW fences on a ring since the device is gone.

Signed-off-by: Andrey Grodzovsky <andrey.grodzov...@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c | 16 ++++++++++------
 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c 
b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
index 1ffb36bd0b19..fa03702ecbfb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_fence.c
@@ -36,6 +36,7 @@
 #include <linux/firmware.h>
 #include <linux/pm_runtime.h>
 
+#include <drm/drm_drv.h>
 #include "amdgpu.h"
 #include "amdgpu_trace.h"
 
@@ -525,8 +526,7 @@ int amdgpu_fence_driver_init(struct amdgpu_device *adev)
  */
 void amdgpu_fence_driver_fini_hw(struct amdgpu_device *adev)
 {
-       unsigned i, j;
-       int r;
+       int i, r;
 
        for (i = 0; i < AMDGPU_MAX_RINGS; i++) {
                struct amdgpu_ring *ring = adev->rings[i];
@@ -535,11 +535,15 @@ void amdgpu_fence_driver_fini_hw(struct amdgpu_device 
*adev)
                        continue;
                if (!ring->no_scheduler)
                        drm_sched_fini(&ring->sched);
-               r = amdgpu_fence_wait_empty(ring);
-               if (r) {
-                       /* no need to trigger GPU reset as we are unloading */
+               /* You can't wait for HW to signal if it's gone */
+               if (!drm_dev_is_unplugged(&adev->ddev))
+                       r = amdgpu_fence_wait_empty(ring);
+               else
+                       r = -ENODEV;
+               /* no need to trigger GPU reset as we are unloading */
+               if (r)
                        amdgpu_fence_driver_force_completion(ring);
-               }
+
                if (ring->fence_drv.irq_src)
                        amdgpu_irq_put(adev, ring->fence_drv.irq_src,
                                       ring->fence_drv.irq_type);
-- 
2.25.1