Patch "gpio: rcar: Check for irq_set_irq_wake() failures" has been added to the 4.1-stable tree

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

gpio: rcar: Check for irq_set_irq_wake() failures

to the 4.1-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:
gpio-rcar-check-for-irq_set_irq_wake-failures.patch
and it can be found in the queue-4.1 subdirectory.

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

From: Geert Uytterhoeven <[email protected]>
Date: Thu, 21 May 2015 13:21:37 +0200
Subject: gpio: rcar: Check for irq_set_irq_wake() failures

From: Geert Uytterhoeven <[email protected]>

commit 501ef0f95a57e7c32138733c468394a52244c85b upstream.

If an interrupt controller doesn't support wake-up configuration, irq_set_irq_wake() returns an error code. Then any subsequent call trying to deconfigure wake-up will cause an imbalance, and a warning will be printed:

    WARNING: CPU: 1 PID: 1341 at kernel/irq/manage.c:540 irq_set_irq_wake+0x9c/0xf8()
    Unbalanced IRQ 26 wake disable

To fix this, refrain from any further parent interrupt controller (de)configuration if irq_set_irq_wake() failed.

Alternative fixes would be:
- calling "gic_set_irqchip_flags(IRQCHIP_SKIP_SET_WAKE)" from the platform code,
- setting "gic_chip.flags = IRQCHIP_SKIP_SET_WAKE" in the GIC driver code,
but these were withheld as the GIC hardware doesn't really support wake-up interrupts.

---
 drivers/gpio/gpio-rcar.c |   11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

@@ -177,8 +177,17 @@ static int gpio_rcar_irq_set_wake(struct
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct gpio_rcar_priv *p = container_of(gc, struct gpio_rcar_priv,
 						gpio_chip);
+	int error;
 
-	irq_set_irq_wake(p->irq_parent, on);
+	if (p->irq_parent) {
+		error = irq_set_irq_wake(p->irq_parent, on);
+		if (error) {
+			dev_dbg(&p->pdev->dev,
+				"irq %u doesn't support irq_set_wake\n",
+				p->irq_parent);
+			p->irq_parent = 0;
+		}
+	}
 
 	if (!p->clk)
 		return 0;

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

queue-4.1/gpio-rcar-check-for-irq_set_irq_wake-failures.patch