ERROR: modpost: "__bad_udelay" [drivers/pwm/pwm-imx27.ko] undefined!

[kernel test robot]

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head:   ab75170520d4964f3acf8bb1f91d34cbc650688e
commit: a25351e4c7740eb22561a3ee4ef17611c6f410b0 pwm: imx27: Workaround of the pwm output bug when decrease the duty cycle
date:   2 months ago
config: um-randconfig-r051-20250104 (https://download.01.org/0day-ci/archive/20250105/202501050459.Cj4jUIXd-lkp@xxxxxxxxx/config)
compiler: clang version 15.0.7 (https://github.com/llvm/llvm-project 8dfdcc7b7bf66834a761bd8de445840ef68e4d1a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250105/202501050459.Cj4jUIXd-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/202501050459.Cj4jUIXd-lkp@xxxxxxxxx/

All errors (new ones prefixed by >>, old ones prefixed by <<):

>> ERROR: modpost: "__bad_udelay" [drivers/pwm/pwm-imx27.ko] undefined!

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki