Re: [PATCH v1 1/3] of: add nvidia,thermtrips property

[Thierry Reding]

On Fri, Dec 07, 2018 at 06:10:05PM +0800, Wei Ni wrote:
> Add optional property "nvidia,thermtrips".
> If present, these trips will be used as HW shutdown trips,
> and critical trips will be used as SW shutdown trips.
> 
> Signed-off-by: Wei Ni <wni@xxxxxxxxxx>
> ---
>  .../bindings/thermal/nvidia,tegra124-soctherm.txt    | 20 +++++++++++++++++---
>  1 file changed, 17 insertions(+), 3 deletions(-)

This seems like an odd exception. Why not extend the list of trip point
types with a "shutdown" or "emergency" type that can be used for this?
This doesn't seem like NVIDIA specific functionality, so adding an
NVIDIA specific property doesn't seem right.

Also, please always Cc devicetree@xxxxxxxxxxxxxxx and the device tree
bindings maintainers when sending updates for a binding. They need to
ack these kinds of patches and they can't do that if they don't get a
copy of the patch.

Cc'ing them now and quoting the full patch for reference.

Thierry

> 
> diff --git a/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt b/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> index b6c0ae53d4dc..ab66d6feab4b 100644
> --- a/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> +++ b/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> @@ -55,10 +55,21 @@ Required properties :
>        - #cooling-cells: Should be 1. This cooling device only support on/off state.
>          See ./thermal.txt for a description of this property.
>  
> +Optional properties:
> +- nvidia,thermtrips : When present, this property specifies the temperature at
> +  which the soctherm hardware will assert the thermal trigger signal to the
> +  Power Management IC, which can be configured to reset or shutdown the device.
> +  It is an array of pairs where each pair represents a tsensor id followed by a
> +  temperature in milli Celcius. In the absence of this property the critical
> +  trip point will be used for thermtrip temperature.
> +
>  Note:
> -- the "critical" type trip points will be set to SOC_THERM hardware as the
> -shut down temperature. Once the temperature of this thermal zone is higher
> -than it, the system will be shutdown or reset by hardware.
> +- the "critical" type trip points will be used to set the temperature at which
> +the SOC_THERM hardware will assert a thermal trigger if the "nvidia,thermtrips"
> +property is missing. When the thermtrips property is present, the breach of a
> +critical trip point is reported back to the thermal framework to implement
> +software shutdown.
> +
>  - the "hot" type trip points will be set to SOC_THERM hardware as the throttle
>  temperature. Once the the temperature of this thermal zone is higher
>  than it, it will trigger the HW throttle event.
> @@ -79,6 +90,9 @@ Example :
>  
>  		#thermal-sensor-cells = <1>;
>  
> +		nvidia,thermtrips = <TEGRA124_SOCTHERM_SENSOR_CPU 102500
> +				     TEGRA124_SOCTHERM_SENSOR_GPU 103000>;
> +
>  		throttle-cfgs {
>  			/*
>  			 * When the "heavy" cooling device triggered,
> -- 
> 2.7.4
>

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