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authorJohan Hovold <johan@kernel.org>2020-11-16 17:18:21 +0100
committerJohan Hovold <johan@kernel.org>2020-12-04 14:57:20 +0100
commit95168d624f3a8dee466525767200391a0fb006b9 (patch)
treedd49ded172847fa86e1b85adc9d492a813ae2b35 /drivers/usb
parent053af9e6e817fe58191b0d27bc67ba329d94ced2 (diff)
USB: serial: cp210x: return early on unchanged termios
Return early from set_termios() in case no relevant terminal settings have changed. This avoids testing each parameter in turn and specifically allows the line-control handling to be cleaned up further. Signed-off-by: Johan Hovold <johan@kernel.org>
Diffstat (limited to 'drivers/usb')
-rw-r--r--drivers/usb/serial/cp210x.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c
index d0c05aa8a0d6..f1fd109d97d5 100644
--- a/drivers/usb/serial/cp210x.c
+++ b/drivers/usb/serial/cp210x.c
@@ -1352,6 +1352,15 @@ static void cp210x_disable_event_mode(struct usb_serial_port *port)
port_priv->event_mode = false;
}
+static bool cp210x_termios_change(const struct ktermios *a, const struct ktermios *b)
+{
+ bool iflag_change;
+
+ iflag_change = ((a->c_iflag ^ b->c_iflag) & INPCK);
+
+ return tty_termios_hw_change(a, b) || iflag_change;
+}
+
static void cp210x_set_termios(struct tty_struct *tty,
struct usb_serial_port *port, struct ktermios *old_termios)
{
@@ -1359,6 +1368,9 @@ static void cp210x_set_termios(struct tty_struct *tty,
unsigned int cflag, old_cflag;
u16 bits;
+ if (!cp210x_termios_change(&tty->termios, old_termios))
+ return;
+
cflag = tty->termios.c_cflag;
old_cflag = old_termios->c_cflag;