Commit 9d552219 authored Dec 10, 2020 by Nikita Shubin Committed by Linus Walleij Dec 12, 2020

gpiolib: irq hooks: fix recursion in gpiochip_irq_unmask

irqchip shared with multiple gpiochips, leads to recursive call of
gpiochip_irq_mask/gpiochip_irq_unmask which was assigned to
rqchip->irq_mask/irqchip->irq_unmask, these happens becouse of
only irqchip->irq_enable == gpiochip_irq_enable is checked.

Let's add an additional check to make sure shared irqchip is detected
even if irqchip->irq_enable wasn't defined.

Fixes: a8173820 ("gpio: gpiolib: Allow GPIO IRQs to lazy disable")
Signed-off-by: Nikita Shubin <nikita.shubin@maquefel.me>
Link: https://lore.kernel.org/r/20201210070514.13238-1-nikita.shubin@maquefel.me

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

parent e6071cad

drivers/gpio/gpiolib.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1419,7 +1419,8 @@ static void gpiochip_set_irq_hooks(struct gpio_chip *gc)
		if (WARN_ON(gc->irq.irq_enable))
		return;
		/* Check if the irqchip already has this hook... */
		if (irqchip->irq_enable == gpiochip_irq_enable) {
		if (irqchip->irq_enable == gpiochip_irq_enable \|\|
		irqchip->irq_mask == gpiochip_irq_mask) {
		/*
		* ...and if so, give a gentle warning that this is bad
		* practice.