On 01/22/2015 02:08 PM, Maciej W. Rozycki wrote:
> On Wed, 21 Jan 2015, Markos Chandras wrote:
>
>>>> diff --git a/arch/mips/kernel/proc.c b/arch/mips/kernel/proc.c
>>>> index 097fc8d14e42..a8fdf9685cad 100644
>>>> --- a/arch/mips/kernel/proc.c
>>>> +++ b/arch/mips/kernel/proc.c
>>>> @@ -82,7 +82,9 @@ static int show_cpuinfo(struct seq_file *m, void *v)
>>>> seq_printf(m, "]\n");
>>>> }
>>>>
>>>> - seq_printf(m, "isa\t\t\t: mips1");
>>>> + seq_printf(m, "isa\t\t\t:");
>>>> + if (!cpu_has_mips_r6)
>>>> + seq_printf(m, " mips1");
>>>
>>> I think define `cpu_has_mips_r1' instead and use it here. It may turn
>>> out needed elsewhere too. We probably don't need a new `MIPS_CPU_ISA_I'
>>> bit at this stage so this could be:
>
> Typo here, I meant `cpu_has_mips_1' actually, sorry about that.
>
>> the change is simple enough and I see no reason to define the
>> cpu_has_mips_r1 at the moment. If we ever need to explicitly handle r1,
>> we can reconsider that.
>
> It's a matter of code clarity, good code is self-explanatory. Here the
> intent is to print `mips1' if it is supported. By avoiding the extra
> definition you're detaching the intent from what code says. Someone
> reading this code (who may not necessarily know the architecture documents
> by heart) has to scratch their head thinking: "why isn't `mips1' printed
> for R6, what the former has to do with the latter, and why is this case
> different to `mips2' and other ones that follow?"
>
> Whereas the intent is clear with this:
>
> #define cpu_has_mips_1 (!cpu_has_mips_r6) // Aha, `mips1' is there if no R6!
>
> if (cpu_has_mips_1)
> seq_printf(m, " mips1"); // Well, this is obvious...
however, someone may wonder then why not have
if (cpu_has_mips_1)
print mips1
if (cpu_has_mips_2)
print mips2
if (cpu_has_mips_3)
print mips3
and only care about mips1.
>
> Do you see what I mean? Do you agree now?
the
if (!cpu_has_mips_r6)
seq_printf(m, " mips1");
means exactly the same thing with
#define cpu_has_mips_1 (!cpu_has_mips_r6) // Aha, `mips1' is there if no R6!
especially since this is the only place that is being used.
I don't see how the differ.
In any case, i don't want such details to block the patchset, so I will
change it.
--
markos
