[PATCH v2] amd/amdgpu: Fix resv shared fence overflow

[xinhui pan]

[  179.556745] kernel BUG at drivers/dma-buf/dma-resv.c:282!
[snip]
[  179.702910] Call Trace:
[  179.705696]  amdgpu_bo_fence+0x21/0x50 [amdgpu]
[  179.710707]  amdgpu_vm_sdma_commit+0x299/0x430 [amdgpu]
[  179.716497]  amdgpu_vm_bo_update_mapping.constprop.0+0x29f/0x390 [amdgpu]
[  179.723927]  ? find_held_lock+0x38/0x90
[  179.728183]  amdgpu_vm_handle_fault+0x1af/0x420 [amdgpu]
[  179.734063]  gmc_v9_0_process_interrupt+0x245/0x2e0 [amdgpu]
[  179.740347]  ? kgd2kfd_interrupt+0xb8/0x1e0 [amdgpu]
[  179.745808]  amdgpu_irq_dispatch+0x10a/0x3c0 [amdgpu]
[  179.751380]  ? amdgpu_irq_dispatch+0x10a/0x3c0 [amdgpu]
[  179.757159]  amdgpu_ih_process+0xbb/0x1a0 [amdgpu]
[  179.762466]  amdgpu_irq_handle_ih1+0x27/0x40 [amdgpu]
[  179.767997]  process_one_work+0x23c/0x580
[  179.772371]  worker_thread+0x50/0x3b0
[  179.776356]  ? process_one_work+0x580/0x580
[  179.780939]  kthread+0x128/0x160
[  179.784462]  ? kthread_park+0x90/0x90
[  179.788466]  ret_from_fork+0x1f/0x30

We have two scheduler entities, immediate and delayed.
So there are two kinds of scheduler finished fences.
We might add these two fences in root bo resv at same time while we
only reserve one slot.

Signed-off-by: xinhui pan <xinhui.pan at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 37221b99ca96..9e0116c7f8d1 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2869,7 +2869,7 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	if (r)
 		goto error_free_root;
 
-	r = dma_resv_reserve_shared(root->tbo.base.resv, 1);
+	r = dma_resv_reserve_shared(root->tbo.base.resv, 2);
 	if (r)
 		goto error_unreserve;
 
-- 
2.25.1