[PATCH 2/8] serial: Use B0 instead of implicit zero assumption

From: Ilpo Järvinen
Date: Thu Mar 09 2023 - 03:11:04 EST


Compare against B0 rather than assume B0 equals zero, which is true for
all archs but explicit B0 makes the code more obvious.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/serial_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index ee2aabcc8943..296d2c33ea7a 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -1662,10 +1662,10 @@ static void uart_set_termios(struct tty_struct *tty,
cflag = tty->termios.c_cflag;

/* Handle transition to B0 status */
- if ((old_termios->c_cflag & CBAUD) && !(cflag & CBAUD))
+ if (((old_termios->c_cflag & CBAUD) != B0) && ((cflag & CBAUD) == B0))
uart_clear_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
/* Handle transition away from B0 status */
- else if (!(old_termios->c_cflag & CBAUD) && (cflag & CBAUD)) {
+ else if (((old_termios->c_cflag & CBAUD) == B0) && ((cflag & CBAUD) != B0)) {
unsigned int mask = TIOCM_DTR;

if (!(cflag & CRTSCTS) || !tty_throttled(tty))
--
2.30.2