Patch "serial: mvebu-uart: free the IRQ in ->shutdown()" has been added to the 4.7-stable tree

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 the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
serial-mvebu-uart-free-the-irq-in-shutdown.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Thomas Petazzoni <[email protected]>
Date: Thu, 16 Jun 2016 16:48:52 +0200
Subject: serial: mvebu-uart: free the IRQ in ->shutdown()

From: Thomas Petazzoni <[email protected]>

commit c2c1659b4f8f9e19fe82a4fd06cca4b3d59090ce upstream.

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.

---
 drivers/tty/serial/mvebu-uart.c |    2 ++
 1 file changed, 2 insertions(+)

@@ -300,6 +300,8 @@ static int mvebu_uart_startup(struct uar
 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,

Patches currently in stable-queue which might be from [email protected] are

queue-4.7/serial-mvebu-uart-free-the-irq-in-shutdown.patch