On 07/30/2015 07:15 PM, Peter Hurley wrote: > 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. Also, seriously consider if you want to use that TI line discipline at all. If you're using it only for bluetooth w/ kernel bluetooth stack, you don't need btwilink + st_drv anyway. 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
