Messages in this thread | | | Date | Tue, 30 Jul 2019 12:27:59 +0100 | From | Will Deacon <> | Subject | Re: [PATCH] arm_pmu: Mark expected switch fall-through |
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On Tue, Jul 30, 2019 at 12:24:15PM +0100, Mark Rutland wrote: > 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.roxell@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.pieralisi@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.rutland@arm.com>
I gave up waiting, so it's already queued here:
https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git/commit/?h=for-next/fixes&id=0d7fd70f26039bd4b33444ca47f0e69ce3ae0354
Will
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