diff options
Diffstat (limited to 'drivers/serial')
| -rw-r--r-- | drivers/serial/serial_core.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c index a9ca03ead3e..977ce820ce3 100644 --- a/drivers/serial/serial_core.c +++ b/drivers/serial/serial_core.c @@ -329,13 +329,15 @@ EXPORT_SYMBOL(uart_update_timeout); * If it's still invalid, we try 9600 baud. * * Update the @termios structure to reflect the baud rate - * we're actually going to be using. + * we're actually going to be using. Don't do this for the case + * where B0 is requested ("hang up"). */ unsigned int uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, struct ktermios *old, unsigned int min, unsigned int max) { unsigned int try, baud, altbaud = 38400; + int hung_up = 0; upf_t flags = port->flags & UPF_SPD_MASK; if (flags == UPF_SPD_HI) @@ -360,8 +362,10 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, /* * Special case: B0 rate. */ - if (baud == 0) + if (baud == 0) { + hung_up = 1; baud = 9600; + } if (baud >= min && baud <= max) return baud; @@ -373,7 +377,9 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, termios->c_cflag &= ~CBAUD; if (old) { baud = tty_termios_baud_rate(old); - tty_termios_encode_baud_rate(termios, baud, baud); + if (!hung_up) + tty_termios_encode_baud_rate(termios, + baud, baud); old = NULL; continue; } @@ -382,7 +388,8 @@ uart_get_baud_rate(struct uart_port *port, struct ktermios *termios, * As a last resort, if the quotient is zero, * default to 9600 bps */ - tty_termios_encode_baud_rate(termios, 9600, 9600); + if (!hung_up) + tty_termios_encode_baud_rate(termios, 9600, 9600); } return 0; |