Re: [PATCH] ARM: dts: exynos: Exynos5422 Odroid-XU* incomplete thermal-zones definition

[Anand Moon]

Hi Krzysztof

On 25 June 2017 at 20:59, Krzysztof Kozlowski <krzk@xxxxxxxxxx> wrote:
> On Sun, Jun 25, 2017 at 08:48:13PM +0530, Anand Moon wrote:
>> Hi Krzystof,
>> >> 2: We should also increase the tips from 4 to 8 to support different
>> >> cluster of cpu's.
>> >
>> > There are 4 CPU thermal zones on Exynos5422. What do you want to expand?
>>
>> What I meant was to support more trip point to address below.
>> [    2.776320] exynos-tmu 100a0000.tmu: More trip points than
>> supported by this TMU.
>> [    2.782370] exynos-tmu 100a0000.tmu: 2 trip points should be
>> configured in polling mode.
>>
>
> I do not understand what you want to achieve. I added 2 trip points in
> polling mode for the CPU cooling mode. Just describe the problem and
> send the patch - it is the best way to explain one's thought...
>
>> >> 3: To avoid duplication of cooling-maps we can make tmu sensor work
>> >> differently for cluster of cpu's
>> >>       tmu_cpu0: handle pwm-fan control.
>> >>       tmu_cpu1: handle cpu[0-3] cpufreq mapping.
>> >>       tmu_cpu2: handle cpu[4-7] cpufreq mapping.
>> >
>> > I miss the point behind this. Why fan should work only when CPU4
>> > (tmu_cpu0) is heated and not CPU5-7 (rest of cpu tmu's)?
>>
>> Ok fan should work on all the thermal zone. To avoid thermal shutdown.
>>
>> But I want to avoid scaling down of all the cores of cpu to low freq
>> as cooling-maps cross the alert temperature. For below example.
>> ----
>>  map3 {
>>               trip = <&cpu1_alert3>;
>>               cooling-device = <&cpu0 0 2>;
>>  };
>>  map4 {
>>               trip = <&cpu1_alert3>;
>>               cooling-device = <&cpu4 0 2>;
>>  };
>>
>>  map5 {
>>               trip = <&cpu1_alert4>;
>>               cooling-device = <&cpu0 3 7>;
>>  };
>>  map6 {
>>              trip = <&cpu1_alert4>;
>>              cooling-device = <&cpu4 3 12>;
>>  };
>>
>> What I want to configure thermal zone as.
>>
>> cpu0_thermal: cpu0-thermal {
>>      configure cluster of cpu[0-3]
>>      {
>>         tips
>>      }
>>      cooling map
>>      {
>>          device handle cpu[0-3] with frequency scaling at particular
>> alert temperature.
>>      }
>> }
>
> cpu0_thermal is attached to tmu_cpu0 which is the temperature of CPU4
> (first big core). I do not see reason behind connecting thermal zone
> (thus temperature) of CPU4 with frequency of LITTLE cluster (CPU0-3). In
> case of busy CPU4, you will scale down CPU0-3. Does not make sense.
>

Both the cpu cluster are independent and have different cpu-freqency scaling.
that is the reason to for my changes.

>> cpu1_thermal: cpu1-thermal {
>>      configure cluster of cpu[4-7]
>>      {
>>         tips
>>      }
>>      cooling map
>>      {
>>          device handle cpu[4-7] with frequency scaling at particular
>> alert temperature.
>>      }
>> }
>>
>> We can chose to configure rest of the thermal-zone on this approach.
>> Please share your thoughts.
>
> I am sorry, I do not understand the idea, the problem nor the solution.
>
> Best regards,
> Krzysztof
>

Sorry for not able to express my self in technical terms.
my changes are based on exynos5433-tmu at this moment.
Just attaching small patch to share my point.

Best Regards
-Anand Moon

Attachment: tmu.patch
Description: Binary data