On devices which do not support break signalling a break condition is simulated by sending a NUL byte at the lowest possible speed. The break condition will be 9 bit periods long (start bit and eight data bits), but the transmission itself also includes the stop bit. Signed-off-by: Johan Hovold <johan@xxxxxxxxxx> --- Hi Michael, I reread the break-end comment and found it a bit confusing still. The below seems more correct to me. I'm assuming you did not intend to add an additional bit period as margin? Johan drivers/usb/serial/ch341.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c index 011d7953f087..27a2a62777c9 100644 --- a/drivers/usb/serial/ch341.c +++ b/drivers/usb/serial/ch341.c @@ -604,9 +604,8 @@ static void ch341_simulate_break(struct tty_struct *tty, int break_state) } /* - * Compute expected transmission duration and add a single bit - * of safety margin (the actual NUL byte transmission is 8 bits - * plus one stop bit). + * Compute expected transmission duration (including stop + * bit). */ priv->break_end = jiffies + (10 * HZ / CH341_MIN_BPS); -- 2.26.2
