[PATCH] powerpc/powernv/cpuidle: Pass correct drv->cpumask for registration

[Michael Ellerman]

Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com> writes:
> * Michael Ellerman <mpe at ellerman.id.au> [2017-03-20 14:05:39]:
>> Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com> writes:
>  
>> > On powernv platform cpu_present could be less than cpu_possible
>> > in cases where firmware detects the cpu, but it is not available
>> > for OS.
>> 
>> It's entirely normal for present < possible, on my laptop for example,
>> so I don't see how that causes the bug.
>
> Yes, present < possible in itself not a problem.  It is whether
> cpu_device exist for that cpu or not.
...
>
> Currently if CONFIG_HOTPLUG_CPU=n, then we skip calling register_cpu()
> and that causes the problem.
...
>> 
>> I really don't understand how a CPU not being present leads to a crash
>> in printf()? Something in that call chain should have checked that the
>> CPU was registered before crashing in printf() - surely?
>
> Yes, we should have just failed to register the cpuidle driver.  I have
> the fix here:
>
> [PATCH] cpuidle: Validate cpu_dev in cpuidle_add_sysfs
> http://patchwork.ozlabs.org/patch/740634/

OK. Can you send a v2 of this with a better change log that includes all
the clarifications above.

And despite your subject being powerpc/powernv/cpuidle, this is a
cpuidle patch. I can merge it, but I at least need you to Cc the cpuidle
maintainers so they have a chance to see it.

cheers