[PATCH v2] gpiolib: Fix GPIO chip IRQ initialization restriction

Jiawen Wu
2023-06-07T08:21:25Z

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>
---
v1 -> v2:
- add compiler barrier
---
drivers/gpio/gpiolib.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index a7220e04a93e..9ecf93cbd801 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1792,6 +1792,14 @@ 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);
--
2.27.0