[patch 23/47] serial: fix serial_match_port() for dynamic major tty-device numbers

Greg KH
2008-07-22T23:26:00Z

[-- Attachment #1: serial-fix-serial_match_port-for-dynamic-major-tty-device-numbers.patch --]
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2.6.25-stable review patch. If anyone has any objections, please let us
know.

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

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>

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

--- 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 */
}

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