diff options
Diffstat (limited to 'drivers/tty/serial/8250/8250_port.c')
| -rw-r--r-- | drivers/tty/serial/8250/8250_port.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 777ef1a9591c..c1891c55897a 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1545,6 +1545,18 @@ static inline void start_tx_rs485(struct uart_port *port) if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) serial8250_stop_rx(&up->port); + /* + * While serial8250_em485_handle_stop_tx() is a noop if + * em485->active_timer != &em485->stop_tx_timer, it might happen that + * the timer is still armed and triggers only after the current bunch of + * chars is send and em485->active_timer == &em485->stop_tx_timer again. + * So cancel the timer. There is still a theoretical race condition if + * the timer is already running and only comes around to check for + * em485->active_timer when &em485->stop_tx_timer is armed again. + */ + if (em485->active_timer == &em485->stop_tx_timer) + hrtimer_try_to_cancel(&em485->stop_tx_timer); + em485->active_timer = NULL; mcr = serial8250_in_MCR(up); @@ -3172,7 +3184,7 @@ static void serial8250_console_restore(struct uart_8250_port *up) serial8250_set_divisor(port, baud, quot, frac); serial_port_out(port, UART_LCR, up->lcr); - serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS); + serial8250_out_MCR(up, up->mcr | UART_MCR_DTR | UART_MCR_RTS); } /* |