[PATCH 1/1] TTY: pdc_cons, fix regression in close

[Jiri Slaby <jslaby@suse.cz>]

The test in pdc_console_tty_close '!tty->count' was always wrong
because tty->count is decremented after tty->ops->close is called and
thus can never be zero. Hence the 'then' branch was never executed and
the timer never deleted.

This did not matter until 5dd5bc40f3b6e0ccdaad948dbadc94ad0906cb25
(TTY: pdc_cons, use tty_port). There we needed to set TTY in tty_port
to NULL, but this never happened due to the bug above.

So change the test to really trigger at the last close by changing the
condition to 'tty->count == 1'.

Well, the driver should not touch tty->count at all. It should use
tty_port->count and count open count there itself.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-and-tested-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <jejb@parisc-linux.org>
---
 arch/parisc/kernel/pdc_cons.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/parisc/kernel/pdc_cons.c b/arch/parisc/kernel/pdc_cons.c
index 4f00459..0b33933 100644
--- a/arch/parisc/kernel/pdc_cons.c
+++ b/arch/parisc/kernel/pdc_cons.c
@@ -104,7 +104,7 @@ static int pdc_console_tty_open(struct tty_struct *tty, struct file *filp)
 
 static void pdc_console_tty_close(struct tty_struct *tty, struct file *filp)
 {
-	if (!tty->count) {
+	if (tty->count == 1) {
 		del_timer_sync(&pdc_console_timer);
 		tty_port_tty_set(&tty_port, NULL);
 	}
-- 
1.7.9.2