Subject: Re: randconfig build error with next-20150112, in drivers/hwmon/gpio-fan.c

From: Guenter Roeck <[email-masked]>
Date: Mon, 12 Jan 2015 09:25:37 -0800

On Mon, Jan 12, 2015 at 09:53:05AM -0700, Jim Davis wrote:
> Building with the attached random configuration file,
> 
> drivers/built-in.o: In function `gpio_fan_remove':
> gpio-fan.c:(.text+0x6efea): undefined reference to
> `thermal_cooling_device_unregister'
> drivers/built-in.o: In function `gpio_fan_probe':
> gpio-fan.c:(.text+0x6f376): undefined reference to
> `thermal_cooling_device_register'
> make: *** [vmlinux] Error 1

Hi Jim,

thanks for the note.

Hmm .. turns out those functions don't define dummies if CONFIG_THERMAL
is not configured. How annoying.

Nishant, please fix your gpio-fan patch. I am going to drop it for now.
Please keep in mind that there is a secondary dependency: The thermal
code can be built as module. In that case, the gpio-fan driver must
either also be built as module, or its thermal registration must be
disabled.

Guenter