gpiolib: irq hooks: fix recursion in gpiochip_irq_unmask

[ Upstream commit 9d5522199505c761575c8ea31dcfd9a2a8d73614 ]

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: a8173820f441 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 6e3c4d7..4ad3c4b 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1477,7 +1477,8 @@ 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.