[PATCH] powerpc/powernv: Select CONFIG_PRINTK to fix build failure

[Michael Ellerman]

On Sat, 2014-12-27 at 12:17 -0500, Pranith Kumar wrote:
> In an allnoconfig we get the following build failure:
 
An allnoconfig doesn't include CONFIG_PPC_POWERNV? But I think I know what you
mean.

> arch/powerpc/platforms/built-in.o: In function `.__machine_initcall_powernv_opal_init':
> opal.c:(.init.text+0x468): undefined reference to `.log_buf_addr_get'
> opal.c:(.init.text+0x474): undefined reference to `.log_buf_len_get'
> make: *** [vmlinux] Error 1
> 
> This happens because powernv requires printk() support. Enable it in the config
> file.

Sort of. It just requires those two routines. Or is there a stronger
dependency?

I think the better fix is for those two routines to be defined for
CONFIG_PRINTK=n, but return NULL and zero respectively.

And the opal code could skip registering the region when they return NULL/zero.

Care to do a couple of patches?

cheers