From: Vitaly Prosyak <[email protected]>
This series fixes two bugs exposed by running the amd_basic IGT test with
AMDGPU_ENABLE_USERQTEST=1 on a GFX12 GPU with CONFIG_LOCKDEP=y enabled.
Bug 1: kernel BUG at drivers/dma-buf/dma-resv.c:319
-----------------------------------------------------
amdgpu_evf_mgr_attach_fence() calls ttm_bo_validate() then
dma_resv_add_fence() without reserving a fence slot first.
ttm_bo_validate() consumes the pre-allocated slots for its own fences,
leaving none for the eviction fence:
kernel BUG at drivers/dma-buf/dma-resv.c:319!
BUG_ON(fobj->num_fences >= fobj->max_fences)
RIP: dma_resv_add_fence+0x294/0x2b0
Workqueue: events amdgpu_userq_restore_worker
Patch 1 adds the missing dma_resv_reserve_fences(resv, 1) call.
Bug 2: four lockdep violations during GPU reset (CONFIG_LOCKDEP=y)
-------------------------------------------------------------------
With lockdep enabled a MES timeout during cs-compute-fwm-UMQ triggers
a GPU reset, exposing four lock ordering violations. All involve
reset_domain->sem being held while other locks that must come before it
in the established ordering are acquired.
The violations (each addressed by one patch):
1. halt_activities() -> drm_client_dev_suspend() takes clientlist_mutex
while reset_domain->sem is already held. Fixed in patch 3 by moving
the reset lock acquisition to after halt_activities().
2. psp_resume() takes firmware.mutex while reset_domain->sem is held.
Fixed in patch 4 by skipping firmware.mutex in reset context, since
down_write(reset_domain->sem) already provides exclusive protection.
3. amdgpu_device_reinit_after_reset() calls drm_client_dev_resume()
which takes clientlist_mutex while reset_domain->sem is held. Fixed
in patch 5 by moving the call to after recovery_put_reset_lock().
4. amdgpu_userq_destroy() calls cancel_delayed_work_sync() inside
userq_mutex; the work itself takes userq_mutex. Fixed in patch 2 by
moving the cancel before mutex_lock().
After all 5 patches the amd_basic UMQ subtests pass with no lockdep
warnings on a CONFIG_LOCKDEP=y / CONFIG_PROVE_LOCKING=y kernel.
Tested-on: GFX12 (Radeon RX 9070 XT / device 0x7550)
IGT amd_basic with AMDGPU_ENABLE_USERQTEST=1
Kernel: 7.1.0+, CONFIG_LOCKDEP=y, CONFIG_PROVE_LOCKING=y
Vitaly Prosyak (5):
drm/amdgpu: reserve dma_resv slot before adding eviction fence
drm/amdgpu: cancel hang_detect_work before taking userq_mutex
drm/amdgpu: take reset lock after halt_activities
drm/amdgpu/psp: skip firmware.mutex in psp_resume during GPU reset
drm/amdgpu: move drm_client_dev_resume outside reset_domain->sem
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 9 ++++---
drivers/gpu/drm/amd/amdgpu/amdgpu_eviction_fence.c | 2 ++
drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 10 ++++----
drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 4 +++-
4 files changed, 17 insertions(+), 8 deletions(-)
Vitaly Prosyak (5):
drm/amdgpu: reserve dma_resv slot before adding eviction fence
drm/amdgpu: cancel hang_detect_work before taking userq_mutex
drm/amdgpu: take reset lock after halt_activities
drm/amdgpu/psp: skip firmware.mutex in psp_resume during GPU reset
drm/amdgpu: move drm_client_dev_resume outside reset_domain->sem
drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 21 ++++++++++++++-----
.../drm/amd/amdgpu/amdgpu_eviction_fence.c | 2 ++
drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 13 +++++++++---
drivers/gpu/drm/amd/amdgpu/amdgpu_userq.c | 5 ++++-
4 files changed, 32 insertions(+), 9 deletions(-)
--
2.54.0
