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authorRussell King <rmk+kernel@arm.linux.org.uk>2012-04-17 16:41:10 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-11-04 11:25:55 +0000
commitdba05832cbe4f305dfd998fb26d7c685d91fbbd8 (patch)
tree823df80fdcdaa66587659bdf2c83106dd71d1c1a /drivers/tty
parent2cbacafd7af0f1cc7a433668c662a91ba6aabc1b (diff)
downloadblackbird-op-linux-dba05832cbe4f305dfd998fb26d7c685d91fbbd8.tar.gz
blackbird-op-linux-dba05832cbe4f305dfd998fb26d7c685d91fbbd8.zip
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>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/serial_core.c7
1 files changed, 7 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);
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