gpiolib: Fix irq_domain resource tracking for gpiochip_irqchip_add_domain()

BugLink: https://bugs.launchpad.net/bugs/2033931
[ Upstream commit ff7a1790fbf92f1bdd0966d3f0da3ea808ede876 ]

Up until commit 6a45b0e2589f ("gpiolib: Introduce
gpiochip_irqchip_add_domain()") all irq_domains were allocated
by gpiolib itself and thus gpiolib also takes care of freeing it.

With gpiochip_irqchip_add_domain() a user of gpiolib can associate an
irq_domain with the gpio_chip. This irq_domain is not managed by
gpiolib and therefore must not be freed by gpiolib.

Fixes: 6a45b0e2589f ("gpiolib: Introduce gpiochip_irqchip_add_domain()")
Reported-by: Jiawen Wu <jiawenwu@trustnetic.com>
Signed-off-by: Michael Walle <mwalle@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index ab88899e09893cb842c5172510402e1416416f01..7c3f83ae864d473210123b431c74b0e3b0eeaaf5 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1711,7 +1711,7 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gc)
        }
 
        /* Remove all IRQ mappings and delete the domain */
-       if (gc->irq.domain) {
+       if (!gc->irq.domain_is_allocated_externally && gc->irq.domain) {
                unsigned int irq;
 
                for (offset = 0; offset < gc->ngpio; offset++) {
@@ -1757,6 +1757,7 @@ int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
 
        gc->to_irq = gpiochip_to_irq;
        gc->irq.domain = domain;
+       gc->irq.domain_is_allocated_externally = true;
 
        /*
         * Using barrier() here to prevent compiler from reordering

diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 44783fc161254bc14071bf26127dbb35a82cd29e..a052427cd263845bfbd0fe1623edeaef5fd8c682 100644 (file)
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -244,6 +244,14 @@ struct gpio_irq_chip {
         */
        bool initialized;
 
+       /**
+        * @domain_is_allocated_externally:
+        *
+        * True it the irq_domain was allocated outside of gpiolib, in which
+        * case gpiolib won't free the irq_domain itself.
+        */
+       bool domain_is_allocated_externally;
+
        /**
         * @init_hw: optional routine to initialize hardware before
         * an IRQ chip will be added. This is quite useful when