Re: [PATCH] acpi-cpufreq: Add a miss ifdef CONFIG_X86_ACPI_CPUFREQ_CPB

From: Rafael J. Wysocki
Date: Mon Jul 13 2015 - 18:59:58 EST


On Monday, July 13, 2015 02:33:08 PM Pan Xinhui wrote:
> hi, Rafeal
> thanks for your reply. :)
>
> On 2015å07æ11æ 04:44, Rafael J. Wysocki wrote:
> > Hi,
> >
> > On Fri, Jul 10, 2015 at 7:50 AM, Pan Xinhui <xinhuix.pan@xxxxxxxxx> wrote:
> >>
> >> If CONFIG_X86_ACPI_CPUFREQ_CPB has not been defined, the placeholder for
> >> cpb is not needed. Add ifdef around it.
> >>
> >> Signed-off-by: Pan Xinhui <xinhuix.pan@xxxxxxxxx>
> >> ---
> >> drivers/cpufreq/acpi-cpufreq.c | 2 ++
> >> 1 file changed, 2 insertions(+)
> >>
> >> diff --git a/drivers/cpufreq/acpi-cpufreq.c b/drivers/cpufreq/acpi-cpufreq.c
> >> index e7fcaa6..314a19e 100644
> >> --- a/drivers/cpufreq/acpi-cpufreq.c
> >> +++ b/drivers/cpufreq/acpi-cpufreq.c
> >> @@ -884,7 +884,9 @@ static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
> >> static struct freq_attr *acpi_cpufreq_attr[] = {
> >> &cpufreq_freq_attr_scaling_available_freqs,
> >> &freqdomain_cpus,
> >> +#ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
> >> NULL, /* this is a placeholder for cpb, do not remove */
> >> +#endif
> >
> > Adding the ifdef here doesn't change anything, because the next NULL
> > will play the role of the one you've just #ifdefed and the structure
> > will be filled with zeros from that point on anyway.
> >
> Yes, adding ifdef here does not change any binary codes. But I want to make the codes more readable. :)
> Patch author has noticed two *NULL* here would confuse people, especially who first read this acpi-cpufreq.c file
> From code style point, it would be better to have #ifdef around it.

Not really.

Why don't you simply drop *both* NULLs?


>
> > You'd need to #ifdef it in the struct freq_attr definition, but I'm
> > not sure it's worth the effort.
> >
>
> struct freq_attr *cpb* is defined in #ifdef section. :)

Ah, OK.


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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