On Thu 2022-04-28 00:13:40, Lecopzer Chen wrote: > With the recent feature added to enable perf events to use pseudo NMIs > as interrupts on platforms which support GICv3 or later, its now been > possible to enable hard lockup detector (or NMI watchdog) on arm64 > platforms. So enable corresponding support. > > One thing to note here is that normally lockup detector is initialized > just after the early initcalls but PMU on arm64 comes up much later as > device_initcall(). To cope with that, overriding watchdog_nmi_probe() to > let the watchdog framework know PMU not ready, and inform the framework > to re-initialize lockup detection once PMU has been initialized. > > [1]: http://lore.kernel.org/linux-arm-kernel/1610712101-14929-1-git-send-email-sumit.garg@xxxxxxxxxx > > --- a/arch/arm64/kernel/perf_event.c > +++ b/arch/arm64/kernel/perf_event.c > @@ -1390,10 +1391,15 @@ static struct platform_driver armv8_pmu_driver = { > > static int __init armv8_pmu_driver_init(void) > { > + int ret; > + > if (acpi_disabled) > - return platform_driver_register(&armv8_pmu_driver); > + ret = platform_driver_register(&armv8_pmu_driver); > else > - return arm_pmu_acpi_probe(armv8_pmuv3_pmu_init); > + ret = arm_pmu_acpi_probe(armv8_pmuv3_pmu_init); > + > + retry_lockup_detector_init(); Does it makes sense to call retry_lockup_detector_init() when the above returned an error? Should it be? if (!ret) retry_lockup_detector_init(); > + return ret; > } > device_initcall(armv8_pmu_driver_init) I am not qualified to ack the arm-specific code. But otherwise the change looks reasonable. Best Regards, Petr
