Hi, With the help of a static bug finder (EBA - https://github.com/models-team/eba) I have found a potential double-lock in drivers/tty/serial/sh-sci.c. This happens due to a recursive spin_lock_irqsave on `port->lock'. If this is indeed a bug, I will be happy to help with a patch. The trace is as follows: 1. Function `rx_timer_fn' takes the lock first in line 1361: // see https://github.com/torvalds/linux/blob/v4.9-rc6/drivers/tty/serial/sh-sci.c#L1361 spin_lock_irqsave(&port->lock, flags); 2. Call to `sci_submit_rx' in line 1409; 3. Enter loop in line 1260; 4. `goto fail' in line 1268; 5. Call to `sci_rx_dma_release' in line 1292; 6. The lock is taken a second time in line 1175: // see https://github.com/torvalds/linux/blob/v4.9-rc6/drivers/tty/serial/sh-sci.c#L1175 spin_lock_irqsave(&port->lock, flags); Hope it helps! -- iago -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
