Symptom:
------------[ cut here ]------------
WARNING: CPU: 2 PID: 1034 at kernel/kthread.c:1430
kthread_destroy_worker+0x84/0x98
Modules linked in: wave5(-) rpmsg_ctrl rpmsg_char ...
Call trace:
kthread_destroy_worker+0x84/0x98
wave5_vpu_remove+0xc8/0xe0 [wave5]
platform_remove+0x30/0x58
...
---[ end trace 0000000000000000 ]---
Root cause:
In polling mode (irq < 0), the driver uses hrtimer to periodically
trigger wave5_vpu_timer_callback() which queues work via
kthread_queue_work(). The kthread_destroy_worker() function validates
that both work queues are empty:
* WARN_ON(!list_empty(&worker->work_list))
* WARN_ON(!list_empty(&worker->delayed_work_list))
The original code called kthread_destroy_worker() before hrtimer_cancel(),
creating a race condition where the timer could fire during worker
destruction and queue new work, triggering the WARN_ON.
Fix:
Reorder cleanup sequence:
1) Cancel hrtimer first - stops the timer from firing and prevents
new work from being queued
2) Cancel current work with kthread_cancel_work_sync() - ensures any
in-flight work completes
3) Destroy worker - now both work queues are guaranteed empty, so
kthread_destroy_worker() won't trigger warnings
Signed-off-by: Xulin Sun <[email protected]>
---
drivers/media/platform/chips-media/wave5/wave5-vpu.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
index 61f0b5468ac3..17d36edba51f 100644
--- a/drivers/media/platform/chips-media/wave5/wave5-vpu.c
+++ b/drivers/media/platform/chips-media/wave5/wave5-vpu.c
@@ -356,8 +356,9 @@ static void wave5_vpu_remove(struct platform_device *pdev)
struct vpu_device *dev = dev_get_drvdata(&pdev->dev);
if (dev->irq < 0) {
- kthread_destroy_worker(dev->worker);
hrtimer_cancel(&dev->hrtimer);
+ kthread_cancel_work_sync(&dev->work);
+ kthread_destroy_worker(dev->worker);
}
pm_runtime_dont_use_autosuspend(&pdev->dev);
--
2.49.1
-=-=-=-=-=-=-=-=-=-=-=-
Links: You receive all messages sent to this group.
View/Reply Online (#16020):
https://lists.yoctoproject.org/g/linux-yocto/message/16020
Mute This Topic: https://lists.yoctoproject.org/mt/116495600/21656
Group Owner: [email protected]
Unsubscribe: https://lists.yoctoproject.org/g/linux-yocto/unsub
[[email protected]]
-=-=-=-=-=-=-=-=-=-=-=-
