From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>

As reported by Vipul Gandhi, the current serial_match_port() doesn't work
for tty-devices using dynamic major number allocation.  Fix it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Tested-by: Vipul Gandhi <vcgandhi1@aol.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 drivers/serial/serial_core.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff -puN drivers/serial/serial_core.c~serial-fix-serial_match_port-for-dynamic-major-tty-device-numbers drivers/serial/serial_core.c
--- a/drivers/serial/serial_core.c~serial-fix-serial_match_port-for-dynamic-major-tty-device-numbers
+++ a/drivers/serial/serial_core.c
@@ -1991,7 +1991,9 @@ struct uart_match {
 static int serial_match_port(struct device *dev, void *data)
 {
 	struct uart_match *match = data;
-	dev_t devt = MKDEV(match->driver->major, match->driver->minor) + match->port->line;
+	struct tty_driver *tty_drv = match->driver->tty_driver;
+	dev_t devt = MKDEV(tty_drv->major, tty_drv->minor_start) +
+		match->port->line;
 
 	return dev->devt == devt; /* Actually, only one tty per port */
 }
_