* [PATCH v2] cpufreq: CPPC: Correct desired_perf calculation
@ 2016-10-13 17:33 Hoan Tran
2016-10-13 19:37 ` Prakash, Prashanth
0 siblings, 1 reply; 4+ messages in thread
From: Hoan Tran @ 2016-10-13 17:33 UTC (permalink / raw)
To: Rafael J. Wysocki, Viresh Kumar, pprakash, Al Stone
Cc: linux-pm, linux-kernel, lho, Duc Dang, Hoan Tran
The desired_perf is an abstract performance number. Its value should
be in the range of [lowest perf, highest perf] of CPPC.
The correct calculation is
desired_perf = freq * cppc_highest_perf / cppc_dmi_max_khz
And cppc_cpufreq_set_target() returns if desired_perf is exactly
the same with the old perf.
Signed-off-by: Hoan Tran <hotran@apm.com>
---
v2
* Return if desired_perf is the same with the old one (Prashanth's suggestion)
drivers/cpufreq/cppc_cpufreq.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c
index 1b2f28f..4852d9e 100644
--- a/drivers/cpufreq/cppc_cpufreq.c
+++ b/drivers/cpufreq/cppc_cpufreq.c
@@ -80,11 +80,17 @@ static int cppc_cpufreq_set_target(struct cpufreq_policy *policy,
{
struct cppc_cpudata *cpu;
struct cpufreq_freqs freqs;
+ u32 desired_perf;
int ret = 0;
cpu = all_cpu_data[policy->cpu];
- cpu->perf_ctrls.desired_perf = (u64)target_freq * policy->max / cppc_dmi_max_khz;
+ desired_perf = (u64)target_freq * cpu->perf_caps.highest_perf / cppc_dmi_max_khz;
+ /* Return if it is exactly the same perf */
+ if (desired_perf == cpu->perf_ctrls.desired_perf)
+ return ret;
+
+ cpu->perf_ctrls.desired_perf = desired_perf;
freqs.old = policy->cur;
freqs.new = target_freq;
--
1.9.1
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v2] cpufreq: CPPC: Correct desired_perf calculation
2016-10-13 17:33 [PATCH v2] cpufreq: CPPC: Correct desired_perf calculation Hoan Tran
@ 2016-10-13 19:37 ` Prakash, Prashanth
2016-10-13 21:12 ` Rafael J. Wysocki
0 siblings, 1 reply; 4+ messages in thread
From: Prakash, Prashanth @ 2016-10-13 19:37 UTC (permalink / raw)
To: Hoan Tran, Rafael J. Wysocki, Viresh Kumar, Al Stone
Cc: linux-pm, linux-kernel, lho, Duc Dang, Christopher Covington
On 10/13/2016 11:33 AM, Hoan Tran wrote:
> The desired_perf is an abstract performance number. Its value should
> be in the range of [lowest perf, highest perf] of CPPC.
> The correct calculation is
> desired_perf = freq * cppc_highest_perf / cppc_dmi_max_khz
>
> And cppc_cpufreq_set_target() returns if desired_perf is exactly
> the same with the old perf.
>
> Signed-off-by: Hoan Tran <hotran@apm.com>
Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
Hi Rafael,
Can you please pick this one for 4.9, as it is bug fix?
--
Thanks,
Prashanth
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] cpufreq: CPPC: Correct desired_perf calculation
2016-10-13 19:37 ` Prakash, Prashanth
@ 2016-10-13 21:12 ` Rafael J. Wysocki
2016-10-13 21:21 ` Hoan Tran
0 siblings, 1 reply; 4+ messages in thread
From: Rafael J. Wysocki @ 2016-10-13 21:12 UTC (permalink / raw)
To: Prakash, Prashanth
Cc: Hoan Tran, Rafael J. Wysocki, Viresh Kumar, Al Stone, Linux PM,
Linux Kernel Mailing List, lho, Duc Dang, Christopher Covington
On Thu, Oct 13, 2016 at 9:37 PM, Prakash, Prashanth
<pprakash@codeaurora.org> wrote:
> On 10/13/2016 11:33 AM, Hoan Tran wrote:
>> The desired_perf is an abstract performance number. Its value should
>> be in the range of [lowest perf, highest perf] of CPPC.
>> The correct calculation is
>> desired_perf = freq * cppc_highest_perf / cppc_dmi_max_khz
>>
>> And cppc_cpufreq_set_target() returns if desired_perf is exactly
>> the same with the old perf.
>>
>> Signed-off-by: Hoan Tran <hotran@apm.com>
> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
>
> Hi Rafael,
> Can you please pick this one for 4.9, as it is bug fix?
Sure, I will queue it up.
Thanks,
Rafael
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH v2] cpufreq: CPPC: Correct desired_perf calculation
2016-10-13 21:12 ` Rafael J. Wysocki
@ 2016-10-13 21:21 ` Hoan Tran
0 siblings, 0 replies; 4+ messages in thread
From: Hoan Tran @ 2016-10-13 21:21 UTC (permalink / raw)
To: Rafael J. Wysocki
Cc: Prakash, Prashanth, Rafael J. Wysocki, Viresh Kumar, Al Stone,
Linux PM, Linux Kernel Mailing List, Loc Ho, Duc Dang,
Christopher Covington
On Thu, Oct 13, 2016 at 2:12 PM, Rafael J. Wysocki <rafael@kernel.org> wrote:
> On Thu, Oct 13, 2016 at 9:37 PM, Prakash, Prashanth
> <pprakash@codeaurora.org> wrote:
>> On 10/13/2016 11:33 AM, Hoan Tran wrote:
>>> The desired_perf is an abstract performance number. Its value should
>>> be in the range of [lowest perf, highest perf] of CPPC.
>>> The correct calculation is
>>> desired_perf = freq * cppc_highest_perf / cppc_dmi_max_khz
>>>
>>> And cppc_cpufreq_set_target() returns if desired_perf is exactly
>>> the same with the old perf.
>>>
>>> Signed-off-by: Hoan Tran <hotran@apm.com>
>> Reviewed-by: Prashanth Prakash <pprakash@codeaurora.org>
>>
>> Hi Rafael,
>> Can you please pick this one for 4.9, as it is bug fix?
>
> Sure, I will queue it up.
>
Thanks, Rafael and Prashanth !
Hoan
> Thanks,
> Rafael
^ permalink raw reply [flat|nested] 4+ messages in thread
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2016-10-13 17:33 [PATCH v2] cpufreq: CPPC: Correct desired_perf calculation Hoan Tran
2016-10-13 19:37 ` Prakash, Prashanth
2016-10-13 21:12 ` Rafael J. Wysocki
2016-10-13 21:21 ` Hoan Tran
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