serial: mvebu-uart: free the IRQ in ->shutdown()
authorThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Thu, 16 Jun 2016 14:48:52 +0000 (16:48 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sat, 25 Jun 2016 21:00:06 +0000 (14:00 -0700)
commitc2c1659b4f8f9e19fe82a4fd06cca4b3d59090ce
treeeb0c874f40d4ac5daf80a0c51b22cfead58c168e
parenta59388668d0ce19dadea909e09f4eb905a27b1ce
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