From: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Date: Fri, 4 Jul 2008 20:05:29 +0000 (+0000)
Subject: serial: fix serial_match_port() for dynamic major tty-device numbers
X-Git-Tag: v2.6.25.12~26
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=81c5896b8f697f5135153055e15cf52da375095a;p=thirdparty%2Fkernel%2Fstable.git

serial: fix serial_match_port() for dynamic major tty-device numbers

commit 7ca796f492a11f9408e661c8f22cd8c4f486b8e5 upstream

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

It oopses if you suspend a serial port with _dynamic_ major number.  ATM,
I think, there's only the drivers/serial/jsm/jsm_driver.c driver, that
does it in-tree.

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index db9920e125dc1..3419a894d6cba 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1950,7 +1950,9 @@ 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 */
 }