diff mbox series

[v5,1/2] dt-bindings: imx8mm-thermal: Document nxp,reboot-on-critical

Message ID 20230824165011.569386-1-festevam@gmail.com
State New
Headers show
Series [v5,1/2] dt-bindings: imx8mm-thermal: Document nxp,reboot-on-critical | expand

Commit Message

Fabio Estevam Aug. 24, 2023, 4:50 p.m. UTC 
From: Fabio Estevam <festevam@denx.de>

Currently, after the SoC reaches the critical temperature, the board
goes through a poweroff mechanism.

In some 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 check the temperature and only allow the boot to
proceed when the temperature is below a certain threshold.

Introduce the 'nxp,reboot-on-critical' property to indicate that the
board will go through a reboot after the critical temperature is reached.

When this property is absent, the default behavior of forcing a shutdown
is kept.

Signed-off-by: Fabio Estevam <festevam@denx.de>
---
Changes since v4:
- None. Went back to using device tree property.

 .../devicetree/bindings/thermal/imx8mm-thermal.yaml         | 6 ++++++
 1 file changed, 6 insertions(+)

Comments

Fabio Estevam Aug. 24, 2023, 9:17 p.m. UTC | #1 
Hi Krzysztof,

On Thu, Aug 24, 2023 at 2:51 PM Krzysztof Kozlowski
<krzysztof.kozlowski@linaro.org> wrote:

> It still does not scale. If it is supposed to be DT property, you need
> to solve my concerns of relying on specific implementation.
>
> First, you need to cover all possible actions, not reverse existing OS
> implementation. As I said before, If Linux decides to reboot by default,
> this property becomes useless. No, it must be some sort of enum defining
> desired allowed action or actions.
>
> Second, I don't think this is specific to this particular device, so
> should be rather common property shared among all thermal handlers (and
> in the future any other critical-condition-handler-devices).

I got your point and it makes sense.

I tested locally with a common DT property like this:

index 4f3acdc4dec0..782cbb4ea487 100644
--- a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
+++ b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
@@ -75,6 +75,14 @@ patternProperties:
           framework and assumes that the thermal sensors in this zone
           support interrupts.

+      critical-action:
+        $ref: /schemas/types.yaml#/definitions/uint32
+        description:
+          The action that happens after the critical temperature is reached.
+          Possible values are 0 for shutdown and 1 for reboot.
+
+        enum: [ 0, 1 ]
+
       thermal-sensors:
         $ref: /schemas/types.yaml#/definitions/phandle-array
         maxItems: 1

Then in the board dts I can use:

+
+       thermal-zones {
+               cpu-thermal {
+                       critical-action = <THERMAL_CRITICAL_ACTION_REBOOT>;
+               };
+       };
 };

I should probably be able to post something next week.

Thanks
Thanks
diff mbox series

Patch

diff --git a/Documentation/devicetree/bindings/thermal/imx8mm-thermal.yaml b/Documentation/devicetree/bindings/thermal/imx8mm-thermal.yaml
index d2c1e4573c32..9ac70360fd35 100644
--- a/Documentation/devicetree/bindings/thermal/imx8mm-thermal.yaml
+++ b/Documentation/devicetree/bindings/thermal/imx8mm-thermal.yaml
@@ -32,6 +32,12 @@  properties:
   clocks:
     maxItems: 1
 
+  nxp,reboot-on-critical:
+    description: Property to indicate that the system will go through a reboot
+      after the critical temperature is reached. If absent, the system will
+      go through shutdown after the critical temperature is reached.
+    type: boolean
+
   nvmem-cells:
     maxItems: 1
     description: Phandle to the calibration data provided by ocotp