patch "serial: mvebu-uart: free the IRQ in ->shutdown()" added to tty-testing

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    serial: mvebu-uart: free the IRQ in ->shutdown()

to my tty git tree which can be found at
    git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-testing branch.

The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)

The patch will be merged to the tty-next branch sometime soon,
after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.


>From c2c1659b4f8f9e19fe82a4fd06cca4b3d59090ce Mon Sep 17 00:00:00 2001
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Date: Thu, 16 Jun 2016 16:48:52 +0200
Subject: serial: mvebu-uart: free the IRQ in ->shutdown()

As suggested by the serial port infrastructure documentation, the IRQ is
requested in ->startup(). However, it is never freed in the ->shutdown()
hook.

With simple systems that open the serial port once for all and always
have at least one process that keep the serial port opened, there was no
problem. But with a more complicated system (*cough* systemd *cough*),
the serial port is opened/closed many times, which at some point no
processes having the serial port open at all. Due to this ->startup()
gets called again, tries to request_irq() again, which fails.

Fixes: 30530791a7a0 ("serial: mvebu-uart: initial support for Armada-3700 serial port")
Cc: <stable@vger.kernel.org>
Cc: Ofer Heifetz <oferh@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/tty/serial/mvebu-uart.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/tty/serial/mvebu-uart.c b/drivers/tty/serial/mvebu-uart.c
index ce362bd51de7..45b57c294d13 100644
--- a/drivers/tty/serial/mvebu-uart.c
+++ b/drivers/tty/serial/mvebu-uart.c
@@ -300,6 +300,8 @@ static int mvebu_uart_startup(struct uart_port *port)
 static void mvebu_uart_shutdown(struct uart_port *port)
 {
 	writel(0, port->membase + UART_CTRL);
+
+	free_irq(port->irq, port);
 }
 
 static void mvebu_uart_set_termios(struct uart_port *port,
-- 
2.9.0