Hi Andy, On Mon, 14 May 2018 20:18:37 +0300, Andy Shevchenko wrote: > On Mon, May 14, 2018 at 12:33 PM, Anders Roxell > <anders.roxell@xxxxxxxxxx> wrote: > > With CONFIG_PM, we get a harmless build warning: > > drivers/i2c/busses/i2c-i801.c:1723:12: warning: ‘i801_resume’ defined but not used [-Wunused-function] > > static int i801_resume(struct device *dev) > > ^~~~~~~~~~~ > > drivers/i2c/busses/i2c-i801.c:1714:12: warning: ‘i801_suspend’ defined but not used [-Wunused-function] > > static int i801_suspend(struct device *dev) > > ^~~~~~~~~~~~ > > > -#ifdef CONFIG_PM > > +#ifdef CONFIG_PM_SLEEP > > static int i801_suspend(struct device *dev) > > The better pattern is to get rid of ugly ifdef and supply > __maybe_unused annotation to each function in question. That was Anders' first proposal, but it was declined by the driver maintainer (me.) See: https://marc.info/?l=linux-kernel&m=152588526520326&w=2 __maybe_unused is just a way to prevent the compiler from doing its job. If it's really what you want, you might as well build with -Wno-unused, instead of crippling the code with yet another annotation. I can't see how building unused code only to discard it later can be better than a proper #ifdef which will only build the code when we actually need it. Maybe there are cases where __maybe_unused is actually needed, but in my opinion that should be the last resort option. That's not the case here. -- Jean Delvare SUSE L3 Support
