Re: [PATCH] drivers/bus: arm-cci: fix build warnings

[Will Deacon]

On Tue, May 29, 2018 at 04:34:01PM +0100, Robin Murphy wrote:
> On 28/05/18 16:41, Arnd Bergmann wrote:
> >When the arm-cci driver is enabled, but both CONFIG_ARM_CCI5xx_PMU and
> >CONFIG_ARM_CCI400_PMU are not, we get a warning about how parts of
> >the driver are never used:
> >
> >drivers/perf/arm-cci.c:1454:29: error: 'cci_pmu_models' defined but not used [-Werror=unused-variable]
> >drivers/perf/arm-cci.c:693:16: error: 'cci_pmu_event_show' defined but not used [-Werror=unused-function]
> >drivers/perf/arm-cci.c:685:16: error: 'cci_pmu_format_show' defined but not used [-Werror=unused-function]
> >
> >Marking all three functions as __maybe_unused avoids the warnings in
> >randconfig builds. I'm doing this lacking any ideas for a better fix.
> 
> Yeah, it's a bit of a silly configuration to allow building a driver
> supporting no PMU types, but I couldn't find a way to enforce "at least one
> sub-option enabled" logic without introducing mutually-exclusive
> dependencies which kbuild thinks are recursive.
> 
> An alternative would be to remove the CCI400/CCI5x0 configurability
> altogether - I've not not looked in detail at how much difference that
> actually makes.
> 
> Otherwise, as an immediate quick-fix:
> 
> Reviewed-by: Robin Murphy <robin.murphy@xxxxxxx>

I'll pick this one up into the arm perf tree.

Will