n_tty: Refactor input_available_p() by call site

Distinguish if caller is n_tty_poll() or n_tty_read(), and
set the read/wakeup threshold accordingly.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 649fd94d1aa6..2caa2936d1b1 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -1869,14 +1869,15 @@ err:
         return -ENOMEM;
 }
 
-static inline int input_available_p(struct tty_struct *tty, int amt)
+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;
 
         if (ldata->icanon && !L_EXTPROC(tty)) {
                 if (ldata->canon_head != ldata->read_tail)
                         return 1;
-        } else if (read_cnt(ldata) >= (amt ? amt : 1))
+        } else if (read_cnt(ldata) >= amt)
                 return 1;
 
         return 0;
@@ -2375,7 +2376,7 @@ static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
 
         poll_wait(file, &tty->read_wait, wait);
         poll_wait(file, &tty->write_wait, wait);
-        if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty)))
+        if (input_available_p(tty, 1))
                 mask |= POLLIN | POLLRDNORM;
         if (tty->packet && tty->link->ctrl_status)
                 mask |= POLLPRI | POLLIN | POLLRDNORM;