On 10/06/2014 08:27 πμ, Viresh Kumar wrote:
> On 10 June 2014 02:30, Stratos Karafotis <strat...@semaphore.gr> wrote:
>> Simplify the code by removing the inline functions
>> pstate_increase and pstate_decrease and use directly the
>> intel_pstate_set_pstate.
>>
>> Signed-off-by: Stratos Karafotis <strat...@semaphore.gr>
>> ---
>> drivers/cpufreq/intel_pstate.c | 26 +++-----------------------
>> 1 file changed, 3 insertions(+), 23 deletions(-)
>>
>> diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
>> index 3a49269..26a0262 100644
>> --- a/drivers/cpufreq/intel_pstate.c
>> +++ b/drivers/cpufreq/intel_pstate.c
>> @@ -588,21 +588,6 @@ static void intel_pstate_set_pstate(struct cpudata
>> *cpu, int pstate)
>> pstate_funcs.set(cpu, pstate);
>> }
>>
>> -static inline void intel_pstate_pstate_increase(struct cpudata *cpu, int
>> steps)
>> -{
>> - int target;
>> - target = cpu->pstate.current_pstate + steps;
>> -
>> - intel_pstate_set_pstate(cpu, target);
>> -}
>> -
>> -static inline void intel_pstate_pstate_decrease(struct cpudata *cpu, int
>> steps)
>> -{
>> - int target;
>> - target = cpu->pstate.current_pstate - steps;
>> - intel_pstate_set_pstate(cpu, target);
>> -}
>> -
>> static void intel_pstate_get_cpu_pstates(struct cpudata *cpu)
>> {
>> cpu->pstate.min_pstate = pstate_funcs.get_min();
>> @@ -695,20 +680,15 @@ static inline void
>> intel_pstate_calc_scaled_busy(struct cpudata *cpu)
>> static inline void intel_pstate_adjust_busy_pstate(struct cpudata *cpu)
>> {
>> struct _pid *pid;
>> - signed int ctl = 0;
>> - int steps;
>> + signed int ctl;
>>
>> pid = &cpu->pid;
>> intel_pstate_calc_scaled_busy(cpu);
>>
>> ctl = pid_calc(pid, cpu->sample.busy_scaled);
>>
>> - steps = abs(ctl);
>> -
>> - if (ctl < 0)
>> - intel_pstate_pstate_increase(cpu, steps);
>> - else
>> - intel_pstate_pstate_decrease(cpu, steps);
>> + /* Negative values of ctl increase the pstate and vice versa */
>> + intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
>> }
>
> I am not very good at this driver but there is some obvious functional
> change here. Earlier we used to pass
> 'cpu->pstate.current_pstate {-|+} steps' and now you are doing '-ctl' only
>
The original code is:
if (ctl < 0)
intel_pstate_pstate_increase(cpu, steps);
else
intel_pstate_pstate_decrease(cpu, steps);
Without inlines functions intel_pstate_pstate_increase() and
intel_pstate_pstate_decrease() we get:
if (ctl < 0)
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate +
steps);
else
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate -
steps);
But steps = abs(ctl), so:
if (ctl < 0)
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate +
abs(ctl));
else
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate -
abs(ctl));
By definition, abs(ctl) = ctl if ctl >= 0, -ctl if ctl < 0. Thus:
if (ctl < 0)
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate +
(-ctl));
else
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
And:
if (ctl < 0)
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
else
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
Finally remove the unnecessary if statement.
intel_pstate_set_pstate(cpu, cpu->pstate.current_pstate - ctl);
So, this is equivalent with the original code.
Thanks,
Stratos
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