On Fri, Jul 26, 2019 at 04:18:25PM +0100, Lorenzo Pieralisi wrote:
> On Fri, Jul 26, 2019 at 01:29:56PM +0100, Mark Rutland wrote:
> > On Fri, Jul 26, 2019 at 01:27:37PM +0200, Anders Roxell wrote:
> > > When fall-through warnings was enabled by default the following warning
> > > was starting to show up:
> > >
> > > ../drivers/perf/arm_pmu.c: In function ‘cpu_pm_pmu_notify’:
> > > ../drivers/perf/arm_pmu.c:726:3: warning: this statement may fall
> > > through [-Wimplicit-fallthrough=]
> > > cpu_pm_pmu_setup(armpmu, cmd);
> > > ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > > ../drivers/perf/arm_pmu.c:727:2: note: here
> > > case CPU_PM_ENTER_FAILED:
> > > ^~~~
> > >
> > > Rework so that the compiler doesn't warn about fall-through.
> > >
> > > Fixes: d93512ef0f0e ("Makefile: Globally enable fall-through warning")
> > > Signed-off-by: Anders Roxell <anders.rox...@linaro.org>
> > > ---
> > >
> > > I'm not convinced that this is the correct patch to fix this issue.
> > > However, I can't see why we do 'armpmu->start(armpmu);' only in 'case
> > > CPU_PM_ENTER_FAILED' and why we not call function cpu_pm_pmu_setup()
> > > there also, since in cpu_pm_pmu_setup() has a case prepared for
> > > CPU_PM_ENTER_FAILED.
> >
> > I agree, think that should be:
> >
> > case CPU_PM_EXIT:
> > case CPU_PM_ENTER_FAILED:
> > cpu_pm_pmu_setup(armpmu, cmd);
> > armpmu->start(armpmu);
> > break;
> >
> > ... so that we re-start the events before we start the PMU.
> >
> > That would be a fix for commit:
> >
> > da4e4f18afe0f372 ("drivers/perf: arm_pmu: implement CPU_PM notifier")
>
> Yes that's correct, apologies. Probably we did not hit it because CPU PM
> notifier entry failures are a pretty rare event; regardless:
>
> Acked-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
>
> I can send the updated fix, just let me know.
I'm not sure what Will wants, but assuming you do so:
Acked-by: Mark Rutland <mark.rutl...@arm.com>
Thanks,
Mark.
