diff options
| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-04-17 16:41:10 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-11-04 11:25:55 +0000 |
| commit | dba05832cbe4f305dfd998fb26d7c685d91fbbd8 (patch) | |
| tree | 823df80fdcdaa66587659bdf2c83106dd71d1c1a | |
| parent | 2cbacafd7af0f1cc7a433668c662a91ba6aabc1b (diff) | |
SERIAL: core: add hardware assisted h/w flow control support
Ports which are handling h/w flow control in hardware must not have
their RTS state altered depending on the tty's hardware-stopped state.
Avoid this additional logic when setting the termios state.
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
| -rw-r--r-- | drivers/tty/serial/serial_core.c | 7 | ||||
| -rw-r--r-- | include/linux/serial_core.h | 2 |
2 files changed, 9 insertions, 0 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index bd10bbd56446..9d8796e77188 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -1255,6 +1255,13 @@ static void uart_set_termios(struct tty_struct *tty, uart_set_mctrl(uport, mask); } + /* + * If the port is doing h/w assisted flow control, do nothing. + * We assume that tty->hw_stopped has never been set. + */ + if (uport->flags & UPF_HARD_FLOW) + return; + /* Handle turning off CRTSCTS */ if ((old_termios->c_cflag & CRTSCTS) && !(cflag & CRTSCTS)) { spin_lock_irqsave(&uport->lock, flags); diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 00051388de3c..e2cda5d04e48 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -163,6 +163,8 @@ struct uart_port { #define UPF_BUGGY_UART ((__force upf_t) (1 << 14)) #define UPF_NO_TXEN_TEST ((__force upf_t) (1 << 15)) #define UPF_MAGIC_MULTIPLIER ((__force upf_t) (1 << 16)) +/* Port has hardware-assisted h/w flow control (iow, auto-RTS *not* auto-CTS) */ +#define UPF_HARD_FLOW ((__force upf_t) (1 << 21)) /* Port has hardware-assisted s/w flow control */ #define UPF_SOFT_FLOW ((__force upf_t) (1 << 22)) #define UPF_CONS_FLOW ((__force upf_t) (1 << 23)) |