On 06/07/2016 04:33 PM, Linus Walleij wrote: > On Tue, Jun 7, 2016 at 9:50 AM, Roger Quadros <rogerq@xxxxxx> wrote: > >> Linus, any idea why of_gpiochip_find_and_xlate() would do a NULL pointer dereference? > > Nope. I see this uses the array fetch function which I did patch around but > "should" not affect this. > >> We have a case here where the GPMC driver registers a gpiochip but after a while >> unregisters it due to some other orthogonal resource not being available. >> Is this registering and unregistering considered acceptable from gpiochip point of view? > > That would be if it doesn't really go away aftert gpiochip_remove() because > some refcount doesn't go zero, so double-check that. It should be fine > anyway though ... just the instance floating around somewhere. > Linus, I've tried to find place in gpiolib.c where gpiochip is removed from gpio_devices list as part of gpiochip_remove(), but I can't. Am I missed smth.? If that is the case then such kind of crash is possible, because gpiochip_find() uses this list. -- regards, -grygorii -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
