On Tue, Apr 25, 2023 at 11:35:48AM +0200, Mirsad Goran Todorovac wrote: > In the function ieee80211_tx_dequeue() there is a particular locking > sequence: > > begin: > spin_lock(&local->queue_stop_reason_lock); > q_stopped = local->queue_stop_reasons[q]; > spin_unlock(&local->queue_stop_reason_lock); > > However small the chance (increased by ftracetest), an asynchronous > interrupt can occur in between of spin_lock() and spin_unlock(), > and the interrupt routine will attempt to lock the same > &local->queue_stop_reason_lock again. > > This will cause a costly reset of the CPU and the wifi device or an > altogether hang in the single CPU and single core scenario. > > This is the probable trace of the deadlock: > > Apr 10 00:58:33 marvin-IdeaPad-3-15ITL6 kernel: Possible unsafe locking scenario: > Apr 10 00:58:33 marvin-IdeaPad-3-15ITL6 kernel: CPU0 > Apr 10 00:58:33 marvin-IdeaPad-3-15ITL6 kernel: ---- > Apr 10 00:58:33 marvin-IdeaPad-3-15ITL6 kernel: lock(&local->queue_stop_reason_lock); > Apr 10 00:58:33 marvin-IdeaPad-3-15ITL6 kernel: <Interrupt> > Apr 10 00:58:33 marvin-IdeaPad-3-15ITL6 kernel: lock(&local->queue_stop_reason_lock); > Apr 10 00:58:33 marvin-IdeaPad-3-15ITL6 kernel: > *** DEADLOCK *** Can you please add to the commit message whole lockdep trace? And please trim "Apr 10 00:58:33 marvin-IdeaPad-3-15ITL6 kernel: " line prefix, it doesn't add any value. Thanks
