gpiolib: Fix GPIO chip IRQ initialization restriction

BugLink: https://bugs.launchpad.net/bugs/2033931
[ Upstream commit 8c00914e5438e3636f26b4f814b3297ae2a1b9ee ]

In case of gpio-regmap, IRQ chip is added by regmap-irq and associated with
GPIO chip by gpiochip_irqchip_add_domain(). The initialization flag was not
added in gpiochip_irqchip_add_domain(), causing gpiochip_to_irq() to return
-EPROBE_DEFER.

Fixes: 5467801f1fcb ("gpio: Restrict usage of GPIO chip irq members before initialization")
Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.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 a3580bc20b56d39f242a3a4f1dd1327521658cf0..ab88899e09893cb842c5172510402e1416416f01 100644 (file)
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1758,6 +1758,14 @@ int gpiochip_irqchip_add_domain(struct gpio_chip *gc,
        gc->to_irq = gpiochip_to_irq;
        gc->irq.domain = domain;
 
+       /*
+        * Using barrier() here to prevent compiler from reordering
+        * gc->irq.initialized before adding irqdomain.
+        */
+       barrier();
+
+       gc->irq.initialized = true;
+
        return 0;
 }
 EXPORT_SYMBOL_GPL(gpiochip_irqchip_add_domain);