Hello Amadeusz Sławiński,
The patch 1b6a6fc5280e: "ALSA: jack: Access input_dev under mutex" from Apr 12, 2022, leads to the following Smatch static checker warning:
sound/core/jack.c:673 snd_jack_report() warn: sleeping in atomic context
sound/core/jack.c 663 jack->hw_status_cache = status; 664 665 list_for_each_entry(jack_kctl, &jack->kctl_list, list) 666 if (jack_kctl->sw_inject_enable) 667 mask_bits |= jack_kctl->mask_bits; 668 else 669 snd_kctl_jack_report(jack->card, jack_kctl->kctl, 670 status & jack_kctl->mask_bits); 671 672 #ifdef CONFIG_SND_JACK_INPUT_DEV --> 673 mutex_lock(&jack->input_dev_lock); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
That patch adds this mutex but we can't take mutex because we're already holding a spinlock. The problematic call trees are:
virtsnd_event_notify_cb() <- disables preempt virtsnd_disable_event_vq() <- disables preempt -> virtsnd_event_dispatch() -> virtsnd_jack_event() -> snd_jack_report()
The virtsnd_event_notify_cb() and virtsnd_disable_event_vq() functions take the spin_lock_irqsave(&queue->lock, flags);
regards, dan carpenter