On 07/30/2015 06:54 PM, John Ogness wrote: > uart_write_wakeup() should be called without holding the port lock. > Otherwise a possible recursive spinlock issue can occur, such as > the following callchain: > > 8250_core.c:serial8250_tx_chars() - called with port locked > serial_core.c:uart_write_wakeup() > tty_io.c:tty_wakeup() > st_core.c:st_tty_wakeup() > st_core.c:st_tx_wakeup() > st_core.c:st_int_write() > serial_core.c:uart_write() - locks port NAK. This is a bug in the N_TI_WL line discipline, specifically in the st_tx_wakeup() function, which cannot perform the write synchronously. This is a common line discipline bug, and typically fixed by performing the wakeup operations from a kworker instead. Regards, Peter Hurley -- 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
