Since commit ff2b13592299 ("gpio: make the gpiochip a real device"),
attempts to add a gpio chip prior to gpiolib initialization cause the
system to crash. Dump a warning to the console and return an error
if the situation is encountered.
Fixes: ff2b13592299 ("gpio: make the gpiochip a real device")
Signed-off-by: Guenter Roeck <[email protected]>
---
drivers/gpio/gpiolib.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 72065532c1c7..ac66219f0611 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -68,6 +68,7 @@ LIST_HEAD(gpio_devices);
static void gpiochip_free_hogs(struct gpio_chip *chip);
static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
+static bool gpiolib_initialized;
static inline void desc_set_label(struct gpio_desc *d, const char *label)
{
@@ -457,6 +458,9 @@ static void gpiodevice_release(struct device *dev)
* the gpio framework's arch_initcall(). Otherwise sysfs initialization
* for GPIOs will fail rudely.
*
+ * gpiochip_add_data() must only be called after gpiolib initialization,
+ * ie after core_initcall().
+ *
* If chip->base is negative, this requests dynamic assignment of
* a range of valid GPIOs.
*/
@@ -468,6 +472,11 @@ int gpiochip_add_data(struct gpio_chip *chip, void *data)
int base = chip->base;
struct gpio_device *gdev;
+ if (!gpiolib_initialized) {
+ WARN(1, "gpiolib not initialized\n");
+ return -EPROBE_DEFER;
+ }
+
/*
* First: allocate and populate the internal stat container, and
* set up the struct device.
@@ -2829,6 +2838,8 @@ static int __init gpiolib_dev_init(void)
if (ret < 0) {
pr_err("gpiolib: failed to allocate char dev region\n");
bus_unregister(&gpio_bus_type);
+ } else {
+ gpiolib_initialized = true;
}
return ret;
}
--
2.5.0
