On Tue, Aug 31, 2010 at 2:37 AM, Anton Vorontsov <cbouatmai...@gmail.com> wrote: > On Tue, Aug 31, 2010 at 02:03:44AM -0600, Grant Likely wrote: >> On Tue, Aug 24, 2010 at 01:26:23PM +0400, Anton Vorontsov wrote: >> > With CONFIG_GPIOLIB=n, the 'struct gpio_chip' is not declared, >> > so the following pops up on PowerPC: >> > >> > cc1: warnings being treated as errors >> > In file included from arch/powerpc/platforms/52xx/mpc52xx_common.c:19: >> > include/linux/of_gpio.h:74: warning: 'struct gpio_chip' declared >> > inside parameter list >> > include/linux/of_gpio.h:74: warning: its scope is only this definition >> > or declaration, which is probably not what >> > you want >> > include/linux/of_gpio.h:75: warning: 'struct gpio_chip' declared >> > inside parameter list >> > make[2]: *** [arch/powerpc/platforms/52xx/mpc52xx_common.o] Error 1 >> > >> > This patch fixes the issue by providing the proper forward declaration. >> > >> > Signed-off-by: Anton Vorontsov <cbouatmai...@gmail.com> >> >> This doesn't actually solve the problem, and gpiochip should >> remain undefined when CONFIG_GPIOLIB=n to catch exactly these >> build failures. The real problem is that I merged a change >> into the mpc5200 code that required CONFIG_GPIOLIB be enabled >> without reflecting that requirement in Kconfig. > > No, look closer. The error is in of_gpio.h, and it's perfectly > fine to include it w/o GPIOLIB=y.
Looking even closer, we're both wrong. You're right I didn't look carefully enough, and the error is in of_gpio.h, not the .c file. However, it is not okay to get the definitions from of_gpio.h when CONFIG_GPIOLIB=n. If GPIOLIB, or more specifically OF_GPIO isn't set, then the of_gpio.h definitions should either not be defined, or should be defined as empty stubs (where appropriate). So, instead of adding a forward declarations of the struct, the correct thing I think to do is to #ifdef out the contents of of_gpio.h when GPIOLIB isn't selected so that extra #includes are completely benign. I've been doing the same thing on the other linux/of*.h headers. I've got a patch in my tree that I'm testing right now and I'll post later today. g. > >> > --- >> > >> > On Tue, Aug 24, 2010 at 04:26:08PM +1000, Benjamin Herrenschmidt wrote: >> > > I get that with my current stuff: >> > > >> > > cc1: warnings being treated as errors >> > > In file included from [..]/mpc52xx_common.c:19: >> > > of_gpio.h:74: error: ‘struct gpio_chip’ declared inside parameter list >> > [...] >> > > make[3]: *** Waiting for unfinished jobs.... >> > >> > That's because with GPIOCHIP=n no one declares struct gpio_chip. >> > >> > It should be either of_gpio.h or gpio.h. Let's make it gpio.h, as >> > this feels more generic, and we already have some !GPIOLIB handling >> > in there. >> > >> > include/linux/gpio.h | 6 ++++++ >> > 1 files changed, 6 insertions(+), 0 deletions(-) >> > >> > diff --git a/include/linux/gpio.h b/include/linux/gpio.h >> > index 03f616b..85207d2 100644 >> > --- a/include/linux/gpio.h >> > +++ b/include/linux/gpio.h >> > @@ -15,6 +15,12 @@ >> > struct device; >> > >> > /* >> > + * Some code might rely on the declaration. Still, it is illegal >> > + * to dereference it for !GPIOLIB case. >> > + */ >> > +struct gpio_chip; >> > + >> > +/* >> > * Some platforms don't support the GPIO programming interface. >> > * >> > * In case some driver uses it anyway (it should normally have >> > -- >> > 1.7.0.5 >> > > > -- > Anton Vorontsov > email: cbouatmai...@gmail.com > irc://irc.freenode.net/bd2 > -- Grant Likely, B.Sc., P.Eng. Secret Lab Technologies Ltd. _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev