Re: [PATCH v9 1/3] dt-bindings: thermal-zones: Document critical-action

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On 01/10/2023 05:00, Fabio Estevam wrote:
From: Fabio Estevam <festevam@xxxxxxx>

Document the critical-action property to describe the thermal action
the OS should perform after the critical temperature is reached.

The possible values are "shutdown" and "reboot".

The motivation for introducing the critical-action property is that
different systems may need different thermal actions when the critical
temperature is reached.

For example, a desktop PC may want the OS to trigger a shutdown
when the critical temperature is reached.

However, in some embedded cases, such behavior does not suit well,
as the board may be unattended in the field and rebooting may be a
better approach.

The bootloader may also benefit from this new property as it can check
the SoC temperature and in case the temperature is above the critical
point, it can trigger a shutdown or reboot accordingly.

Signed-off-by: Fabio Estevam <festevam@xxxxxxx>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@xxxxxxxxxx>
---
Changes since v8:
- Go back to putting critical-action as a thermal-zone property. (Daniel)

  .../devicetree/bindings/thermal/thermal-zones.yaml       | 9 +++++++++
  1 file changed, 9 insertions(+)

diff --git a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
index 4f3acdc4dec0..c2e4d28f885b 100644
--- a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
+++ b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
@@ -75,6 +75,15 @@ patternProperties:
            framework and assumes that the thermal sensors in this zone
            support interrupts.
+ critical-action:
+        $ref: /schemas/types.yaml#/definitions/string
+        description:
+          The action the OS should perform after the critical temperature is reached.
+
+        enum:
+          - shutdown
+          - reboot

This option is dangerous and should be more documented.

"The action the OS should perform after the critical temperature is reached. By default the system will shutdown as a safe action to prevent to damage the hardware if the property is not set. The shutdown action should be always the default. Choose carefully 'reboot' as the hardware may be in thermal stress, thus leading to infinite reboots damaging the hardware. Make sure the firmware will act as the last resort and take over the thermal control."

[ and more info if needed ]

(written with best effort with my non native language ;)

        thermal-sensors:
          $ref: /schemas/types.yaml#/definitions/phandle-array
          maxItems: 1

--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog





[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]


  Powered by Linux