diff mbox series

arm: dts: mt7623: increase passive cooling trip

Message ID 20210725163451.217610-1-linux@fw-web.de (mailing list archive)
State New, archived
Headers show
Series arm: dts: mt7623: increase passive cooling trip | expand

Commit Message

Frank Wunderlich July 25, 2021, 4:34 p.m. UTC
From: Frank Wunderlich <frank-w@public-files.de>

MT7623/BPI-R2 has idle temperature after bootup from 48 degrees celsius
increase the passive trip temp threshold to not trottle CPU frequency at
this temperature

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
---
 arch/arm/boot/dts/mt7623.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Matthias Brugger Aug. 4, 2021, 5:15 p.m. UTC | #1
On 25/07/2021 18:34, Frank Wunderlich wrote:
> From: Frank Wunderlich <frank-w@public-files.de>
> 
> MT7623/BPI-R2 has idle temperature after bootup from 48 degrees celsius
> increase the passive trip temp threshold to not trottle CPU frequency at
> this temperature
> 
> Signed-off-by: Frank Wunderlich <frank-w@public-files.de>

pushed to v5.14-next/dts32

Thanks!

> ---
>  arch/arm/boot/dts/mt7623.dtsi | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/arm/boot/dts/mt7623.dtsi b/arch/arm/boot/dts/mt7623.dtsi
> index b7247ab082aa..11933494e03d 100644
> --- a/arch/arm/boot/dts/mt7623.dtsi
> +++ b/arch/arm/boot/dts/mt7623.dtsi
> @@ -160,7 +160,7 @@ cpu_thermal: cpu-thermal {
>  
>  				trips {
>  					cpu_passive: cpu-passive {
> -						temperature = <47000>;
> +						temperature = <57000>;
>  						hysteresis = <2000>;
>  						type = "passive";
>  					};
>
Kurt Fitzner March 5, 2022, 3:54 p.m. UTC | #2
This issue and patch just came to my attention, my apologies for late 
comments.

The solution provided in this patch is, I believe, not optimal.

On 2021-07-25 1:34 p.m., Frank Wunderlich wrote:
> From: Frank Wunderlich <frank-w@public-files.de>
> 
> MT7623/BPI-R2 has idle temperature after bootup from 48 degrees celsius
> increase the passive trip temp threshold to not trottle CPU frequency at
> this temperature

The dts file for the mt7623 has four trip points:
- Trip point 0, Type=Passive @ 47°C (originally, now 57°C)
- Trip point 1, Type=Active @ 67°C
- Trip point 2, Type=Hot @ 87°C
- Trip point 3, Type=Critical @ 107°C

It makes little sense to have passive CPU throttling employed *before* 
engaging a fan.  Generally users want a fan (if present) to be engaged 
before intentional performance degradation is employed.

>   					cpu_passive: cpu-passive {
> -						temperature = <47000>;
> +						temperature = <57000>;

The old temperature of 47°C appears, in practice, to be a good 
temperature for an active cooling trip point.  It is just above the 
temperature that a generally idle mt7623 sits at in enclosures where 
this SoC is employed, but also a temperature that a CPU under load will 
quickly reach.

Therefore I propose the types of trip points 0 and 1 be reversed and the 
temperatures left as they were.


--- a/arch/arm/boot/dts/mt7623.dtsi	2022-02-27 18:36:33 -0400
+++ b/arch/arm/boot/dts/mt7623.dtsi	2022-03-05 11:37:52 -0400
@@ -158,19 +158,19 @@

  				thermal-sensors = <&thermal 0>;

  				trips {
  					cpu_passive: cpu-passive {
-						temperature = <57000>;
+						temperature = <47000>;
  						hysteresis = <2000>;
-						type = "passive";
+						type = "active";
  					};

  					cpu_active: cpu-active {
  						temperature = <67000>;
  						hysteresis = <2000>;
-						type = "active";
+						type = "passive";
  					};

  					cpu_hot: cpu-hot {
  						temperature = <87000>;
  						hysteresis = <2000>;
Frank Wunderlich March 5, 2022, 4:37 p.m. UTC | #3
Hi Kurt,

> Gesendet: Samstag, 05. März 2022 um 16:54 Uhr
> Von: "Kurt Fitzner" <kurt@va1der.ca>

> This issue and patch just came to my attention, my apologies for late 
> comments.
> 
> The solution provided in this patch is, I believe, not optimal.

does your Patch fixes the issue? if yes you can send a Patch based on current mainline dts.

it looks a bit weired to me having active before passive...but i'm no expert in the cooling trips. 
i just increased the temps :)

please see notes below

> On 2021-07-25 1:34 p.m., Frank Wunderlich wrote:
> > From: Frank Wunderlich <frank-w@public-files.de>
> > 
> > MT7623/BPI-R2 has idle temperature after bootup from 48 degrees celsius
> > increase the passive trip temp threshold to not trottle CPU frequency at
> > this temperature
> 
> The dts file for the mt7623 has four trip points:
> - Trip point 0, Type=Passive @ 47°C (originally, now 57°C)
> - Trip point 1, Type=Active @ 67°C
> - Trip point 2, Type=Hot @ 87°C
> - Trip point 3, Type=Critical @ 107°C
> 
> It makes little sense to have passive CPU throttling employed *before* 
> engaging a fan.  Generally users want a fan (if present) to be engaged 
> before intentional performance degradation is employed.
> 
> >   					cpu_passive: cpu-passive {
> > -						temperature = <47000>;
> > +						temperature = <57000>;
> 
> The old temperature of 47°C appears, in practice, to be a good 
> temperature for an active cooling trip point.  It is just above the 
> temperature that a generally idle mt7623 sits at in enclosures where 
> this SoC is employed, but also a temperature that a CPU under load will 
> quickly reach.
> 
> Therefore I propose the types of trip points 0 and 1 be reversed and the 
> temperatures left as they were.
> 
> 
> --- a/arch/arm/boot/dts/mt7623.dtsi	2022-02-27 18:36:33 -0400
> +++ b/arch/arm/boot/dts/mt7623.dtsi	2022-03-05 11:37:52 -0400
> @@ -158,19 +158,19 @@
> 
>   				thermal-sensors = <&thermal 0>;
> 
>   				trips {
>   					cpu_passive: cpu-passive {
> -						temperature = <57000>;
> +						temperature = <47000>;
>   						hysteresis = <2000>;
> -						type = "passive";
> +						type = "active";
>   					};

if type is different, imho the name+label should be changed too

>   					cpu_active: cpu-active {
>   						temperature = <67000>;
>   						hysteresis = <2000>;
> -						type = "active";
> +						type = "passive";
>   					};

dito

>   					cpu_hot: cpu-hot {
>   						temperature = <87000>;
>   						hysteresis = <2000>;

regards Frank
diff mbox series

Patch

diff --git a/arch/arm/boot/dts/mt7623.dtsi b/arch/arm/boot/dts/mt7623.dtsi
index b7247ab082aa..11933494e03d 100644
--- a/arch/arm/boot/dts/mt7623.dtsi
+++ b/arch/arm/boot/dts/mt7623.dtsi
@@ -160,7 +160,7 @@  cpu_thermal: cpu-thermal {
 
 				trips {
 					cpu_passive: cpu-passive {
-						temperature = <47000>;
+						temperature = <57000>;
 						hysteresis = <2000>;
 						type = "passive";
 					};