On Wed, May 31, 2017 at 11:43 AM, Arend van Spriel <arend.vanspriel@xxxxxxxxxxxx> 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