On Wed, Aug 16, 2023 at 11:23:17PM +0200, Ulf Hansson wrote:

On Wed, 16 Aug 2023 at 22:46, Daniel Lezcano [off-list ref] wrote:

quoted

On 16/08/2023 19:07, Frank Li wrote:

quoted

On Wed, Aug 16, 2023 at 06:47:17PM +0200, Daniel Lezcano wrote:

quoted

On 16/08/2023 18:28, Frank Li wrote:

quoted

On Wed, Aug 16, 2023 at 10:44:32AM +0200, Daniel Lezcano wrote:

quoted

Hi Frank,

sorry for the delay

On 14/07/2023 19:19, Frank Li wrote:

quoted

On Thu, Jul 13, 2023 at 02:49:54PM +0200, Daniel Lezcano wrote:

quoted

On 12/07/2023 23:05, Frank Li wrote:

quoted

Avoid endless print following message when SCFW turns off resource.
     [ 1818.342337] thermal thermal_zone0: failed to read out thermal zone (-1)

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
     drivers/thermal/imx_sc_thermal.c | 4 +++-
     1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/thermal/imx_sc_thermal.c b/drivers/thermal/imx_sc_thermal.c
index 8d6b4ef23746..0533d58f199f 100644
--- a/drivers/thermal/imx_sc_thermal.c
+++ b/drivers/thermal/imx_sc_thermal.c

@@ -58,7 +58,9 @@ static int imx_sc_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
        hdr->size = 2;
        ret = imx_scu_call_rpc(thermal_ipc_handle, &msg, true);
-       if (ret)
+       if (ret == -EPERM) /* NO POWER */
+               return -EAGAIN;

Isn't there a chain call somewhere when the resource is turned off, so the
thermal zone can be disabled?

A possible place in drivers/firmware/imx/scu-pd.c. but I am not sure how to
get thermal devices. I just found a API thermal_zone_get_zone_by_name(). I
am not sure if it is good to depend on "name", which add coupling between
two drivers and if there are external thermal devices(such as) has the
same name, it will wrong turn off.

Correct

quoted

If add power domain notification in thermal driver, I am not how to get
other devices's pd in thermal driver.

Any example I can refer?

Or this is simple enough solution.

The solution works for removing the error message but it does not solve the
root cause of the issue. The thermal zone keeps monitoring while the sensor
is down.

So the question is why the sensor is shut down if it is in use?

Do you know if there are any code I reference? I supposed it is quite common.

Sorry, I don't get your comment

What I meant is why is the sensor turned off if it is in use ?

One typical example is cpu hotplug. The sensor is located CPU power domain.
If CPU hotplug off,  CPU power domain will be turn off.

It doesn't make sensor keep monitor such sensor when CPU already power off.
It doesn't make sensor to keep CPU power on just because want to get sensor
data.

Anthor example is GPU, if there are GPU0 and GPU1. Most case just GPU0
work.  GPU1 may turn off when less loading.

Ideally, thermal can get notification from power domain driver.
when such power domain turn off,  disable thermal zone.

So far, I have not idea how to do that.

Ulf,

do you have a guidance to link the thermal zone and the power domain in
order to get a poweron/off notification leading to enable/disable the
thermal zone ?

I don't know the details here, so apologize for my ignorance to start
with. What platform is this?

i.MX8QM.

A vague idea could be to hook up the thermal sensor to the
corresponding CPU power domain. Assuming the CPU power domain is
modelled as a genpd provider, then this allows the driver for the
thermal sensor to register for power-on/off notifications of the genpd
(see dev_pm_genpd_add_notifier()).

Can this work?

I don't think. dev_pm_genpd_ad_notifier() need a dev, which binded to pd.

tsens: thermal-sensor {
	compatible = "fsl,imx-sc-thermal";
        tsens-num = <6>;
        #thermal-sensor-cells = <1>;
};

we have 6 thermal-sensor, which assocated with 6 pd, 
	IMX_SC_R_SYSTEM, IMX_SC_R_PMIC_0,
        IMX_SC_R_AP_0, IMX_SC_R_AP_1,
        IMX_SC_R_GPU_0_PID0, IMX_SC_R_GPU_1_PID0,
        IMX_SC_R_DRC_0

We don't want to hold PD on just because want to get temperature. GPU pd
consume much power.

I want to register one callback at thermal-sensor driver, when GPU pd on,
enable thermal-zone. when GPU pd off, disable thermal zone.

we can do more common way. 

	gpu-thermal1 {
                        polling-delay-passive = <250>;
                        polling-delay = <2000>;
	>>>		pd=<&GPU1_PD>
                        thermal-sensors = <&tsens IMX_SC_R_GPU_1_PID0>;

                };

if GPU1_PD on, then gpu-thermal1 enable,
if GPU1_PD off, then gpu-thermal1 disable.

Kind regards
Uffe

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