diff options
| -rw-r--r-- | drivers/gpio/gpiolib.c | 19 | ||||
| -rw-r--r-- | include/linux/gpio/driver.h | 9 |
2 files changed, 28 insertions, 0 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 358f0ad9d0f8..91628edad2c6 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1368,6 +1368,16 @@ static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset) { struct irq_domain *domain = gc->irq.domain; +#ifdef CONFIG_GPIOLIB_IRQCHIP + /* + * Avoid race condition with other code, which tries to lookup + * an IRQ before the irqchip has been properly registered, + * i.e. while gpiochip is still being brought up. + */ + if (!gc->irq.initialized) + return -EPROBE_DEFER; +#endif + if (!gpiochip_irqchip_irq_valid(gc, offset)) return -ENXIO; @@ -1552,6 +1562,15 @@ static int gpiochip_add_irqchip(struct gpio_chip *gc, acpi_gpiochip_request_interrupts(gc); + /* + * Using barrier() here to prevent compiler from reordering + * gc->irq.initialized before initialization of above + * GPIO chip irq members. + */ + barrier(); + + gc->irq.initialized = true; + return 0; } diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index a0f9901dcae6..e3c29d2e6826 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -225,6 +225,15 @@ struct gpio_irq_chip { unsigned int ngpios); /** + * @initialized: + * + * Flag to track GPIO chip irq member's initialization. + * This flag will make sure GPIO chip irq members are not used + * before they are initialized. + */ + bool initialized; + + /** * @valid_mask: * * If not %NULL, holds bitmask of GPIOs which are valid to be included |