Re: [External] : RE: Re : [PATCH v5 3/5] thermal: renesas: rzg3e: Add thermal driver for the Renesas RZ/G3E SoC

[ALOK TIWARI <alok.a.tiwari@oracle.com>]

Hi John,

On 03-04-2025 00:52, John Madieu wrote:
> Hi Alok,
> 
>> -----Original Message-----
>> From: ALOK TIWARI <alok.a.tiwari@oracle.com>
>> Sent: Tuesday, April 1, 2025 8:24 PM
>> To: John Madieu <john.madieu.xa@bp.renesas.com>; geert+renesas@glider.be;
>> conor+dt@kernel.org; krzk+dt@kernel.org; robh@kernel.org;
>> rafael@kernel.org; daniel.lezcano@linaro.org
>> Subject: Re : [PATCH v5 3/5] thermal: renesas: rzg3e: Add thermal driver
>> for the Renesas RZ/G3E SoC
>>
>> Hi John,
>>
>> Thanks for your reply.
>>
>> On 01-04-2025 17:35, John Madieu wrote:
>>> Hi Alok,
>>>
>>> Thanks for your feedback.
>>>
>>>> -----Original Message-----
>>>> From: ALOK TIWARI <alok.a.tiwari@oracle.com>
>>>> Sent: Monday, March 31, 2025 8:11 PM
>>>> To: John Madieu <john.madieu.xa@bp.renesas.com>;
>>>> geert+renesas@glider.be;
>>>> conor+dt@kernel.org; krzk+dt@kernel.org; robh@kernel.org;
>>>> rafael@kernel.org; daniel.lezcano@linaro.org
>>>> Subject: Re : [PATCH v5 3/5] thermal: renesas: rzg3e: Add thermal
>>>> driver for the Renesas RZ/G3E SoC
>>>>
>>>>
>>>>
>>>> On 31-03-2025 03:19, John Madieu wrote:
>>>>> The RZ/G3E SoC integrates a Temperature Sensor Unit (TSU) block
>>
>>>>> +static int rzg3e_thermal_change_mode(struct thermal_zone_device *tz,
>>>>> +				     enum thermal_device_mode mode) {
>>>>> +	struct rzg3e_thermal_priv *priv = thermal_zone_device_priv(tz);
>>>>> +
>>>>> +	if (mode == THERMAL_DEVICE_DISABLED)
>>>>> +		rzg3e_thermal_hw_disable(priv);
>>>>> +	else
>>>>> +		rzg3e_thermal_hw_enable(priv);
>>>>> +
>>>>> +	priv->mode = mode;
>>>>> +	return 0;
>>>>> +}
>>>>> +
>>>> always return 0 here ? what, if (!priv) return -EINVAL; ?
>>>
>>> priv cannot be NULL here, guaranteed from probe().
>>> Returning 0 here is expected by the thermal framework to notify ops
>>> success.
>>>
>>
>> I agreed. priv cannot be NULL.
>> It appears that return 0 is deliberate in this case. can we add Meaningful
>> comment which help to code readability.
>>
> 
> This is a standard tzd ops, which expects 0 to be returned
> for disabling/enabling success. This is how it's implemented
> in every Thermal driver I've gone through in the -next tree.
> 
>> not sure if user call ioctl(fd, THERMAL_IOC_SET_MODE, 2) and it returns
>> 0 with thermal enable.
>> that create possibility to thermal_core call thermal_notify_tz_disable if
>> any case
>>
> Am I missing something ?
> 

That's fine. it is not supporting ioctl.
usually thermal core driver do check if(mode == THERMAL_DEVICE_ENABLED) 
condition, else part is by-default.
as it is supporting only enable/disable case from 
/sys/class/thermal/thermal_zone0/mode. it does not create any issue.
LGTM.

>>>>> +static const struct thermal_zone_device_ops rzg3e_tz_ops = {
>>>>> +	.get_temp = rzg3e_thermal_get_temp,
>>>>> +	.set_trips = rzg3e_thermal_set_trips,
>>>>> +	.change_mode = rzg3e_thermal_change_mode, };
>>>> other renesas driver defined as rzg2l_tz_of_ops, can be used similar
>>>> one rzg3e_tz_of_ops for consistency!
>>>
>>> Thanks for pointing it out. Makes sense. Will double check and update
>>> accordingly.
>>>
>>>>> +
>>>>> +static int rzg3e_thermal_probe(struct platform_device *pdev) {
>>>>> +	struct device *dev = &pdev->dev;
>>>>> +	struct rzg3e_thermal_priv *priv;
>>>>> +	struct reset_control *rstc;
>>>>
> Regards,
> John