Hi Daniel,

I love your patch! Yet something to improve:

[auto build test ERROR on pm/linux-next]
[cannot apply to v5.4-rc1 next-20191003]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Daniel-Lezcano/cpuidle-play_idle-Make-play_idle-more-flexible/20191003-171142
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
config: x86_64-allyesconfig (attached as .config)
compiler: gcc-7 (Debian 7.4.0-13) 7.4.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

If you fix the issue, kindly add following tag
Reported-by: kbuild test robot <lkp@intel.com>

Note: the linux-review/Daniel-Lezcano/cpuidle-play_idle-Make-play_idle-more-flexible/20191003-171142 HEAD 67d70fb96ed26998f13be3c91ed6cc5440390408 builds fine.
      It only hurts bisectibility.

All errors (new ones prefixed by >>):

   drivers/powercap/idle_inject.c: In function 'idle_inject_fn':
>> drivers/powercap/idle_inject.c:142:5: error: implicit declaration of function 'cpuidle_find_deepest_state'; did you mean 'cpu_report_state'? [-Werror=implicit-function-declaration]
        cpuidle_find_deepest_state());
        ^~~~~~~~~~~~~~~~~~~~~~~~~~
        cpu_report_state
   cc1: some warnings being treated as errors

vim +142 drivers/powercap/idle_inject.c

   120	
   121	/**
   122	 * idle_inject_fn - idle injection work function
   123	 * @cpu: the CPU owning the task
   124	 *
   125	 * This function calls play_idle() to inject a specified amount of CPU idle
   126	 * time.
   127	 */
   128	static void idle_inject_fn(unsigned int cpu)
   129	{
   130		struct idle_inject_device *ii_dev;
   131		struct idle_inject_thread *iit;
   132	
   133		ii_dev = per_cpu(idle_inject_device, cpu);
   134		iit = per_cpu_ptr(&idle_inject_thread, cpu);
   135	
   136		/*
   137		 * Let the smpboot main loop know that the task should not run again.
   138		 */
   139		iit->should_run = 0;
   140	
   141		play_idle(READ_ONCE(ii_dev->idle_duration_us),
 > 142			  cpuidle_find_deepest_state());
   143	}
   144	

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