[PATCH] ARM64 / SMP: Switch pr_err() to pr_debug() for disabled GICC entry

Hanjun Guo guohanjun at huawei.com
Thu Jul 2 18:18:42 PDT 2015

On 2015/7/3 1:38, Mark Salter wrote:
> On Wed, 2015-07-01 at 21:37 +0800, Hanjun Guo wrote:
>> It is normal that firmware presents GICC entry or entries (processors)
>> with disabled flag in ACPI MADT, taking a system of 16 cpus for example,
>> ACPI firmware may present 8 enabled first with another 8 cpus disabled
>> in MADT, the disabled cpus can be hot-added later.
>> Firmware may also present more cpus than the hardware actually has, but
>> disabled the unused ones, and easily enable it when the hardware has such
>> cpus to make the firmware code scalable.
>> So that's not an error for disabled cpus in MADT, we can switch
>> pr_err() to pr_debug() instead.
> I agree with pr_debug instead of pr_err, but for hotplug to work
> I think we need to continue to parse the MADT instead of bailing
> out altogether, right? We need to know at init time how many

Yes, agreed :)

> possible cpus there are and that number never changes as cpus
> are plugged/unplugged. Right now, set_cpu_possible() only gets
> called if smp_cpu_setup() gets called and smp_cpu_setup() only
> gets called if the cpu is in the cpu_logical_map.

We need some extra work to make the physical CPU hotplug work
on ARM64.


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