The timer used by delayed kthread works are IRQ safe because the used kthread_delayed_work_timer_fn() is IRQ safe. It is properly marked when initialized by KTHREAD_DELAYED_WORK_INIT(). But TIMER_IRQSAFE flag is missing when initialized by kthread_init_delayed_work(). The missing flag might trigger invalid warning from del_timer_sync() when kthread_mod_delayed_work() is called with interrupts disabled. Reported-by: Grygorii Strashko <grygorii.strashko@xxxxxx> Signed-off-by: Petr Mladek <pmladek@xxxxxxxx> Tested-by: Grygorii Strashko <grygorii.strashko@xxxxxx> --- This patch is result of a discussion about using the API, see https://lkml.kernel.org/r/cfa886ad-e3b7-c0d2-3ff8-58d94170eab5@xxxxxx include/linux/kthread.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/linux/kthread.h b/include/linux/kthread.h index 0f9da966934e..8bbcaad7ef0f 100644 --- a/include/linux/kthread.h +++ b/include/linux/kthread.h @@ -165,7 +165,8 @@ extern void __kthread_init_worker(struct kthread_worker *worker, do { \ kthread_init_work(&(dwork)->work, (fn)); \ timer_setup(&(dwork)->timer, \ - kthread_delayed_work_timer_fn, 0); \ + kthread_delayed_work_timer_fn, \ + TIMER_IRQSAFE); \ } while (0) int kthread_worker_fn(void *worker_ptr); -- 2.16.4