[PATCH] bcm47xx: fix build regression

[Arnd Bergmann]

On Wed, May 31, 2017 at 11:43 AM, Arend van Spriel
<arend.vanspriel at broadcom.com> wrote:
> On 5/30/2017 1:20 PM, Arnd Bergmann wrote:
>>
>> An unknown change in the kernel headers caused a build regression
>> in an MTD partition driver:
>>
>> In file included from drivers/mtd/bcm47xxpart.c:12:0:
>> include/linux/bcm47xx_nvram.h: In function 'bcm47xx_nvram_init_from_mem':
>> include/linux/bcm47xx_nvram.h:27:10: error: 'ENOTSUPP' undeclared (first
>> use in this function)
>>
>> Clearly we want to include linux/errno.h here.
>
>
> unfortunate that you did not find the commit that caused this build
> regression. You could produce preprocessor output when it was working to see
> where errno.h got implicitly included and start looking there for git
> history.

I did a 'git bisect run make drivers/mtd/bcm47xxpart.o' now, which pointed to
0bc2d534708b ("rcu: Refactor #includes from include/linux/rcupdate.h").

That commit seems reasonable, it was just bad luck that it caused this
regression. The commit is currently in the rcu/rcu/next branch of tip.git,
so Paul could merge the patch there.

       Arnd