From: Johan Hovold johan@kernel.org
commit a08ca6ebafe615c9028c53fc4c9e6c9b2b1f2888 upstream.
The driver leaves the line speed unchanged in case a requested speed is not supported. Make sure to handle the case where the current speed is B0 (hangup) without dividing by zero when determining the clock source.
Fixes: 268ddb5e9b62 ("USB: serial: f81232: add high baud rate support") Cc: stable@vger.kernel.org # 5.2 Cc: Ji-Ze Hong (Peter Hong) hpeter@gmail.com Reviewed-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Johan Hovold johan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/serial/f81232.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-)
--- a/drivers/usb/serial/f81232.c +++ b/drivers/usb/serial/f81232.c @@ -78,9 +78,6 @@ static u8 const clock_table[] = { F81232
static int calc_baud_divisor(speed_t baudrate, speed_t clockrate) { - if (!baudrate) - return 0; - return DIV_ROUND_CLOSEST(clockrate, baudrate); }
@@ -423,9 +420,14 @@ static void f81232_set_baudrate(struct t speed_t baud_list[] = { baudrate, old_baudrate, F81232_DEF_BAUDRATE };
for (i = 0; i < ARRAY_SIZE(baud_list); ++i) { - idx = f81232_find_clk(baud_list[i]); + baudrate = baud_list[i]; + if (baudrate == 0) { + tty_encode_baud_rate(tty, 0, 0); + return; + } + + idx = f81232_find_clk(baudrate); if (idx >= 0) { - baudrate = baud_list[i]; tty_encode_baud_rate(tty, baudrate, baudrate); break; }