From 66528f90669691c85c73bea4f0c9f4a5857c4cab Mon Sep 17 00:00:00 2001 From: Peter Hurley Date: Mon, 16 Jun 2014 08:10:42 -0400 Subject: tty: Correct INPCK handling If INPCK is not set, input parity detection should be disabled. This means parity errors should not be received from the tty driver, and the data received should be treated normally. SUS v3, 11.2.2, General Terminal Interface - Input Modes, states: "If INPCK is set, input parity checking shall be enabled. If INPCK is not set, input parity checking shall be disabled, allowing output parity generation without input parity errors. Note that whether input parity checking is enabled or disabled is independent of whether parity detection is enabled or disabled (see Control Modes). If parity detection is enabled but input parity checking is disabled, the hardware to which the terminal is connected shall recognize the parity bit, but the terminal special file shall not check whether or not this bit is correctly set." Ignore parity errors reported by the tty driver when INPCK is not set, and handle the received data normally. Fixes: Bugzilla #71681, 'Improvement of n_tty_receive_parity_error from n_tty.c' Reported-by: Ivan Signed-off-by: Peter Hurley Signed-off-by: Greg Kroah-Hartman --- drivers/tty/n_tty.c | 19 ++++++++++--------- 1 file changed, 10 insertions(+), 9 deletions(-) (limited to 'drivers/tty') diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index f95569dedc88..f44f1ba762c3 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -1214,15 +1214,16 @@ static void n_tty_receive_parity_error(struct tty_struct *tty, unsigned char c) { struct n_tty_data *ldata = tty->disc_data; - if (I_IGNPAR(tty)) - return; - if (I_PARMRK(tty)) { - put_tty_queue('\377', ldata); - put_tty_queue('\0', ldata); - put_tty_queue(c, ldata); - } else if (I_INPCK(tty)) - put_tty_queue('\0', ldata); - else + if (I_INPCK(tty)) { + if (I_IGNPAR(tty)) + return; + if (I_PARMRK(tty)) { + put_tty_queue('\377', ldata); + put_tty_queue('\0', ldata); + put_tty_queue(c, ldata); + } else + put_tty_queue('\0', ldata); + } else put_tty_queue(c, ldata); if (waitqueue_active(&tty->read_wait)) wake_up_interruptible(&tty->read_wait); -- cgit v1.2.3