From f4bbae27b32ea0ffb9e25931b9769600e8d8a664 Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Sun, 4 Jun 2023 14:35:04 +0200 Subject: [PATCH] USB: serial: cp210x: disable break signalling on CP2105 SCI Only the first UART interface (ECI) on CP2105 supports break signalling. Return an error on requests for break state changes for the second interface (SCI) to avoid transmitting a garbage character and waiting when break is not supported. Tested-by: Corey Minyard Signed-off-by: Johan Hovold --- drivers/usb/serial/cp210x.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/usb/serial/cp210x.c b/drivers/usb/serial/cp210x.c index 81e49ed9d147..1e61fe043171 100644 --- a/drivers/usb/serial/cp210x.c +++ b/drivers/usb/serial/cp210x.c @@ -1437,8 +1437,14 @@ static int cp210x_tiocmget(struct tty_struct *tty) static int cp210x_break_ctl(struct tty_struct *tty, int break_state) { struct usb_serial_port *port = tty->driver_data; + struct cp210x_serial_private *priv = usb_get_serial_data(port->serial); u16 state; + if (priv->partnum == CP210X_PARTNUM_CP2105) { + if (cp210x_interface_num(port->serial) == 1) + return -ENOTTY; + } + if (break_state == 0) state = BREAK_OFF; else -- 2.11.0