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Date: Thu, 5 Mar 2015 14:23:56 +0100
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Subject: Re: [PATCH v9 02/21] ACPI / processor: Introduce phys_cpuid_t for CPU
 hardware ID
From: "Rafael J. Wysocki" <rafael@kernel.org>
To: Hanjun Guo <guohanjun@huawei.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Hanjun Guo <hanjun.guo@linaro.org>,
        Catalin Marinas <catalin.marinas@arm.com>,
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On Thu, Mar 5, 2015 at 8:44 AM, Hanjun Guo <guohanjun@huawei.com> wrote:
> On 2015/3/5 6:29, Rafael J. Wysocki wrote:
>> On Wednesday, February 25, 2015 04:39:42 PM Hanjun Guo wrote:

[cut]

>>> @@ -190,7 +190,7 @@ int acpi_map_cpuid(int phys_id, u32 acpi_id)
>>>              if (nr_cpu_ids <= 1 && acpi_id == 0)
>>>                      return acpi_id;
>>>              else
>>> -                    return phys_id;
>>> +                    return -1;
>> Can we use a proper error code here?
>
> I'm afraid not. In ACPI processor drivers, -1 will be deemed to
> invalid cpu logical number, if we return error code here, we need
> to modify multi places of "if (cpu_logical_num == -1)" to

Oh, silly stuff.

> "if (! (cpu_logical_num < 0))" too, so for me, I prefer to keep it as
> -1, but I'm open for suggestions.

OK

I think we need something like invalid_logical_cpuid() and use it
in all of those checks instead of the direct comparisons, but we
can make those changes later.

Rafael