[PATCH v2] ARM: dts: exynos: enable polling in Exynos 4210

[PATCH v2] ARM: dts: exynos: enable polling in Exynos 4210

[Mateusz Majewski]

It seems that thermal in Exynos 4210 is broken without this, as it will
never decrease cooling after increasing it.

Signed-off-by: Mateusz Majewski <m.majewski2@samsung.com>
---
v1 -> v2: Just uploaded separately from all the thermal: exynos:
  patches with a shorter recipient list, no change otherwise.

 arch/arm/boot/dts/samsung/exynos4210.dtsi | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm/boot/dts/samsung/exynos4210.dtsi b/arch/arm/boot/dts/samsung/exynos4210.dtsi
index 0e27c3375e2e..aae185b7f91c 100644
--- a/arch/arm/boot/dts/samsung/exynos4210.dtsi
+++ b/arch/arm/boot/dts/samsung/exynos4210.dtsi
@@ -391,8 +391,14 @@ &cpu_alert2 {
 };
 
 &cpu_thermal {
-	polling-delay-passive = <0>;
-	polling-delay = <0>;
+	/* Exynos 4210 supports thermal interrupts, but only for the rising threshold.
+	 * This means that polling is not needed for preventing overheating, but only
+	 * for decreasing cooling when possible. Hence we poll with a high delay.
+	 * Ideally, we would disable polling for the first trip point, but this isn't
+	 * really possible without outrageous hacks.
+	 */
+	polling-delay-passive = <5000>;
+	polling-delay = <5000>;
 };
 
 &gic {
-- 
2.41.0

Re: [PATCH v2] ARM: dts: exynos: enable polling in Exynos 4210

[Krzysztof Kozlowski]

On 11/09/2023 15:34, Mateusz Majewski wrote:
> It seems that thermal in Exynos 4210 is broken without this, as it will
> never decrease cooling after increasing it.
> 
> Signed-off-by: Mateusz Majewski <m.majewski2@samsung.com>
> ---
> v1 -> v2: Just uploaded separately from all the thermal: exynos:
>   patches with a shorter recipient list, no change otherwise.
> 
>  arch/arm/boot/dts/samsung/exynos4210.dtsi | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm/boot/dts/samsung/exynos4210.dtsi b/arch/arm/boot/dts/samsung/exynos4210.dtsi
> index 0e27c3375e2e..aae185b7f91c 100644
> --- a/arch/arm/boot/dts/samsung/exynos4210.dtsi
> +++ b/arch/arm/boot/dts/samsung/exynos4210.dtsi
> @@ -391,8 +391,14 @@ &cpu_alert2 {
>  };
>  
>  &cpu_thermal {
> -	polling-delay-passive = <0>;
> -	polling-delay = <0>;
> +	/* Exynos 4210 supports thermal interrupts, but only for the rising threshold.

This is a friendly reminder during the review process.

It seems my previous comments were not fully addressed. Maybe my
feedback got lost between the quotes, maybe you just forgot to apply it.
Please go back to the previous discussion and either implement all
requested changes or keep discussing them.

I fixed it up and applied.

Best regards,
Krzysztof

Re: [PATCH v2] ARM: dts: exynos: enable polling in Exynos 4210

[Krzysztof Kozlowski]

On 14/09/2023 10:01, Krzysztof Kozlowski wrote:
> On 11/09/2023 15:34, Mateusz Majewski wrote:
>> It seems that thermal in Exynos 4210 is broken without this, as it will
>> never decrease cooling after increasing it.
>>
>> Signed-off-by: Mateusz Majewski <m.majewski2@samsung.com>
>> ---
>> v1 -> v2: Just uploaded separately from all the thermal: exynos:
>>   patches with a shorter recipient list, no change otherwise.
>>
>>  arch/arm/boot/dts/samsung/exynos4210.dtsi | 10 ++++++++--
>>  1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/boot/dts/samsung/exynos4210.dtsi b/arch/arm/boot/dts/samsung/exynos4210.dtsi
>> index 0e27c3375e2e..aae185b7f91c 100644
>> --- a/arch/arm/boot/dts/samsung/exynos4210.dtsi
>> +++ b/arch/arm/boot/dts/samsung/exynos4210.dtsi
>> @@ -391,8 +391,14 @@ &cpu_alert2 {
>>  };
>>  
>>  &cpu_thermal {
>> -	polling-delay-passive = <0>;
>> -	polling-delay = <0>;
>> +	/* Exynos 4210 supports thermal interrupts, but only for the rising threshold.
> 
> This is a friendly reminder during the review process.
> 
> It seems my previous comments were not fully addressed. Maybe my
> feedback got lost between the quotes, maybe you just forgot to apply it.
> Please go back to the previous discussion and either implement all
> requested changes or keep discussing them.
> 
> I fixed it up and applied.
> 

BTW, line wrapping was also not correct :/ Please follow coding style -
it is still 80, unless exception makes things readable. There is no need
for exception here.

Best regards,
Krzysztof

Re: [PATCH v2] ARM: dts: exynos: enable polling in Exynos 4210

[Krzysztof Kozlowski]

On Mon, 11 Sep 2023 15:34:14 +0200, Mateusz Majewski wrote:
> It seems that thermal in Exynos 4210 is broken without this, as it will
> never decrease cooling after increasing it.
> 
> 

Applied, thanks!

[1/1] ARM: dts: exynos: enable polling in Exynos 4210
      https://git.kernel.org/krzk/linux/c/ef399736c3ba77fb82d778b1b7285baa65a7e079

Best regards,
-- 
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>