Currrently the gpio_chip.to_irq() callback returns -ENOSYS on error,
which causes bad interactions with the serial_mctrl_gpio helpers.
mctrl_gpio_init() returns -ENOSYS if GPIOLIB is not enabled, which is
intended to be ignored by its callers. However, ignoring -ENOSYS when it
was caused by a gpiod_to_irq() failure will lead to a crash later:
Unable to handle kernel paging request at virtual address ffffffde
...
PC is at mctrl_gpio_set+0x14/0x78
Fix this by returning -ENXIO instead.
Signed-off-by: Geert Uytterhoeven <geert+rene...@glider.be>
---
Is -ENXIO the right error code?
- Most drivers seem to return -ENXIO on failure, just like
gpiod_to_irq() does when no .to_irq() callback is provided by the
driver,
- Some drivers use -EINVAL,
- Drivers that call irq_find_mapping(), irq_create_mapping(), or
irq_create_fwspec_mapping() return zero! This also applies to the
core helper gpiochip_to_irq().
---
drivers/pinctrl/sh-pfc/gpio.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/pinctrl/sh-pfc/gpio.c b/drivers/pinctrl/sh-pfc/gpio.c
index a6681b8b17c3b30c..2fffb9c32231adb3 100644
--- a/drivers/pinctrl/sh-pfc/gpio.c
+++ b/drivers/pinctrl/sh-pfc/gpio.c
@@ -212,7 +212,7 @@ static int gpio_pin_to_irq(struct gpio_chip *gc, unsigned
offset)
}
}
- return -ENOSYS;
+ return -ENXIO;
found:
return pfc->irqs[i];
--
1.9.1
