On Wed, May 31, 2017 at 3:12 PM, Paul E. McKenney
[off-list ref] wrote:

On Wed, May 31, 2017 at 12:21:10PM +0200, Arnd Bergmann wrote:

quoted

On Wed, May 31, 2017 at 11:43 AM, Arend van Spriel
[off-list ref] wrote:

quoted

On 5/30/2017 1:20 PM, Arnd Bergmann wrote:

quoted

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.

Apologies for the inconvenience, not sure why 0day test robot didn't
find this.  Probably because it cannot test each and every driver.  ;-)

No worries.

This patch, correct?

        https://lkml.org/lkml/2017/5/30/348

Right, I should have included the link.

      Arnd