Re: ERROR: modpost: "__delay" [drivers/net/mdio/mdio-cavium.ko] undefined!

[Geert Uytterhoeven]

Hi Kernel Test Robot,

On Sat, Dec 28, 2024 at 2:36 PM kernel test robot <lkp@xxxxxxxxx> wrote:
> First bad commit (maybe != root cause):
>
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head:   fd0584d220fe285dc45be43eede55df89ad6a3d9
> commit: a9770eac511ad82390b9f4a3c1728e078c387ac7 net: mdio: Move MDIO drivers into a new subdirectory
> date:   4 years, 4 months ago
> config: sh-randconfig-001-20241212 (https://download.01.org/0day-ci/archive/20241228/202412282326.0DSE4HbR-lkp@xxxxxxxxx/config)
> compiler: sh4-linux-gcc (GCC) 12.4.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241228/202412282326.0DSE4HbR-lkp@xxxxxxxxx/reproduce)
>
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@xxxxxxxxx>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202412282326.0DSE4HbR-lkp@xxxxxxxxx/
>
> All errors (new ones prefixed by >>, old ones prefixed by <<):
>
> >> ERROR: modpost: "__delay" [drivers/net/mdio/mdio-cavium.ko] undefined!

The real issue was introduced in commit 1eefee901fca0208
("phy: mdio-octeon: Refactor into two files/modules").

Drivers must not use __delay() directly, as that is non-portable, and
doesn't work in the presence of cpufreq.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds