From 171948ea33e14dd1e49ba6439eabe822449ffd21 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Fri, 14 Sep 2018 10:36:39 +0200 Subject: gpiolib: check if irqchip already has the irq hook replacements Some drivers use a single irqchip for multiple gpiochips. As a result the irqchip hooks are overridden for the first gpiochip that was added, but for the other gpiochip instances this should not happen again, otherwise we would go into an infinite recursion. Check for this, but also log a message that the driver should be fixed since this is bad practice. Signed-off-by: Hans Verkuil Tested-by: Heikki Krogerus Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'drivers') diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 74f3af2d8ca0..940180b5704e 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1858,6 +1858,16 @@ static void gpiochip_set_irq_hooks(struct gpio_chip *gpiochip) } if (WARN_ON(gpiochip->irq.irq_enable)) return; + /* Check if the irqchip already has this hook... */ + if (irqchip->irq_enable == gpiochip_irq_enable) { + /* + * ...and if so, give a gentle warning that this is bad + * practice. + */ + chip_info(gpiochip, + "detected irqchip that is shared with multiple gpiochips: please fix the driver.\n"); + return; + } gpiochip->irq.irq_enable = irqchip->irq_enable; gpiochip->irq.irq_disable = irqchip->irq_disable; irqchip->irq_enable = gpiochip_irq_enable; -- cgit v1.2.3-59-g8ed1b