Commit a5934804 authored Feb 11, 2014 by Peter Hurley Committed by Greg Kroah-Hartman Feb 13, 2014

n_tty: Fix poll() when TIME_CHAR and MIN_CHAR == 0



Commit eafbe67f,
  n_tty: Refactor input_available_p() by call site
broke poll() when TIME_CHAR(tty) and MIN_CHAR(tty) are both 0.

When TIME_CHAR and MIN_CHAR are both 0, input is available if the
read_cnt is 1 (not 0).

Reported-by: Eric Dumazet <edumazet@google.com>
Tested-by: Eric Dumazet <edumazet@google.com>
Reported-by: Stephane Eranian <eranian@google.com>
Tested-by: David Ahern <dsahern@gmail.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent a64c1a1c

drivers/tty/n_tty.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1896,7 +1896,7 @@ static int n_tty_open(struct tty_struct *tty)
		static inline int input_available_p(struct tty_struct *tty, int poll)
		{
		struct n_tty_data *ldata = tty->disc_data;
		int amt = poll && !TIME_CHAR(tty) ? MIN_CHAR(tty) : 1;
		int amt = poll && !TIME_CHAR(tty) && MIN_CHAR(tty) ? MIN_CHAR(tty) : 1;

		if (ldata->icanon && !L_EXTPROC(tty)) {
		if (ldata->canon_head != ldata->read_tail)