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authorPeter Hurley <peter@hurleysoftware.com>2014-06-16 08:10:42 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-07-09 11:21:31 -0700
commit6442220792dfa623e8e0d98a5a6b4af4aa456fb9 (patch)
tree9390f2656bb1e349fd7c9924cb9e261dc57cdba9
parenta774d0fc92d5c33bc295d07c109162f2aeab249d (diff)
tty: Correct INPCK handling
commit 66528f90669691c85c73bea4f0c9f4a5857c4cab upstream. 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 <athlon_@mail.ru> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/n_tty.c19
1 files changed, 10 insertions, 9 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index fe9d129c8735..0391f17020f6 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);