From: Ilpo Järvinen ilpo.jarvinen@linux.intel.com
[ Upstream commit 52bb1cb7118564166b04d52387bd8403632f5190 ]
Only CS7 and CS8 seem supported but CSIZE is not sanitized from CS5 or CS6 to CS8. In addition, ASC_CTL_MODE_7BIT_PAR suggests that CS7 has to have parity, thus add PARENB.
Incorrect CSIZE results in miscalculation of the frame bits in tty_get_char_size() or in its predecessor where the roughly the same code is directly within uart_update_timeout().
Fixes: c4b058560762 (serial:st-asc: Add ST ASC driver.) Cc: Srinivas Kandagatla srinivas.kandagatla@st.com Signed-off-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Link: https://lore.kernel.org/r/20220519081808.3776-8-ilpo.jarvinen@linux.intel.co... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/tty/serial/st-asc.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c index d7fd692286cf..1b0da603ab54 100644 --- a/drivers/tty/serial/st-asc.c +++ b/drivers/tty/serial/st-asc.c @@ -535,10 +535,14 @@ static void asc_set_termios(struct uart_port *port, struct ktermios *termios, /* set character length */ if ((cflag & CSIZE) == CS7) { ctrl_val |= ASC_CTL_MODE_7BIT_PAR; + cflag |= PARENB; } else { ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR : ASC_CTL_MODE_8BIT; + cflag &= ~CSIZE; + cflag |= CS8; } + termios->c_cflag = cflag;
/* set stop bit */ ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT;