The `drm_atomic_helper_shutdown(dev)` is called only if
`priv->is_registered` is true, ensuring that it runs only when the device
has been properly registered. Otherwise, if it encounters a defer probe,
the following call trace will appear.
WARNING: CPU: 0 PID: 13 at drivers/gpu/drm/drm_atomic_state_helper.c:174 drm_atomic_helper_crtc_duplicate_state+0x68/0x70
Modules linked in:
CPU: 0 PID: 13 Comm: kworker/u2:1
Hardware name: Generic AM33XX (Flattened Device Tree)
Workqueue: events_unbound deferred_probe_work_func
unwind_backtrace from show_stack+0x18/0x1c
show_stack from dump_stack_lvl+0x24/0x2c
dump_stack_lvl from __warn+0x80/0x134
__warn from warn_slowpath_fmt+0x19c/0x1a4
warn_slowpath_fmt from drm_atomic_helper_crtc_duplicate_state+0x68/0x70
drm_atomic_helper_crtc_duplicate_state from drm_atomic_get_crtc_state+0x70/0x110
drm_atomic_get_crtc_state from drm_atomic_helper_disable_all+0x98/0x1c8
drm_atomic_helper_disable_all from drm_atomic_helper_shutdown+0x90/0x144
drm_atomic_helper_shutdown from tilcdc_fini+0x58/0xe0
tilcdc_fini from tilcdc_init.constprop.0+0x23c/0x620
tilcdc_init.constprop.0 from tilcdc_pdev_probe+0x58/0xac
tilcdc_pdev_probe from platform_probe+0x64/0xb8
platform_probe from really_probe+0xd0/0x2e0
really_probe from __driver_probe_device+0x90/0x1a8
__driver_probe_device from driver_probe_device+0x38/0x10c
driver_probe_device from __device_attach_driver+0x9c/0x110
__device_attach_driver from bus_for_each_drv+0x98/0xec
bus_for_each_drv from __device_attach+0xb0/0x1ac
__device_attach from bus_probe_device+0x90/0x94
bus_probe_device from deferred_probe_work_func+0x80/0xac
deferred_probe_work_func from process_one_work+0x198/0x3f8
process_one_work from worker_thread+0x35c/0x550
worker_thread from kthread+0x108/0x124
kthread from ret_from_fork+0x14/0x28
Exception stack(0xe0039fb0 to 0xe0039ff8)
9fa0: 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
---[ end trace 0000000000000000 ]---
tilcdc 4830e000.lcdc: [drm] *ERROR* Disabling all crtc's during unload failed with -12
Signed-off-by: Xulin Sun <xulin.sun@xxxxxxxxxxxxx>
---
drivers/gpu/drm/tilcdc/tilcdc_drv.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/tilcdc/tilcdc_drv.c b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
index cd5eefa06060..9c11ea126b46 100644
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -171,11 +171,12 @@ static void tilcdc_fini(struct drm_device *dev)
if (priv->crtc)
tilcdc_crtc_shutdown(priv->crtc);
- if (priv->is_registered)
+ if (priv->is_registered) {
drm_dev_unregister(dev);
+ drm_atomic_helper_shutdown(dev);
+ }
drm_kms_helper_poll_fini(dev);
- drm_atomic_helper_shutdown(dev);
tilcdc_irq_uninstall(dev);
drm_mode_config_cleanup(dev);
--
2.34.1
