[PATCH] gpiolib: fix: do not access oftree on non-OFDEVICE boards

[Lucas Stach]

Am Sonntag, den 02.07.2017, 22:24 +0200 schrieb Alexander Kurz:
> Non-OFDEVICE boards may have OFTREE=y set, e.g. by BOOTM_OFTREE.
> Attempts to browse the oftree will crash barebox on those boards.
> 
> Signed-off-by: Alexander Kurz <akurz at blala.de>
> ---
>  drivers/gpio/gpiolib.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index a3e17ad..a1ff965 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -416,7 +416,10 @@ int gpiochip_add(struct gpio_chip *chip)
>  	for (i = chip->base; i < chip->base + chip->ngpio; i++)
>  		gpio_desc[i].chip = chip;
>  
> -	return of_gpiochip_scan_hogs(chip);
> +	if (IS_ENABLED(CONFIG_OFDEVICE))
> +		return of_gpiochip_scan_hogs(chip);
> +	else
> +		return 0;

This may also crash in mixed oftree/board file based systems (however
unlikely that is). I think an early return from of_gpiochip_scan_hogs ()
if chip->dev->device_node is NULL would be more robust.

Regards,
Lucas