Re: [PATCH] thermal: of: Fix logic in thermal_of_should_bind

[Lukasz Luba <lukasz.luba@arm.com>]

Hi Rafael,

On 2/20/25 20:22, Rafael J. Wysocki wrote:
> On Wed, Feb 19, 2025 at 10:40 PM Rafael J. Wysocki <rafael@kernel.org> wrote:
>>
>> On Wed, Feb 19, 2025 at 8:06 AM Yu-Che Cheng <giver@chromium.org> wrote:
>>>
>>> The current thermal_of_should_bind will stop iterating cooling-maps on
>>> the first matched trip point, leading to subsequent cooling devices
>>> binding to the same trip point failing to find the cooling spec.
>>>
>>> The iteration should continue enumerating subsequent cooling-maps if the
>>> target cooling device is not found.
>>>
>>> Fix the logic to break only when a matched cooling device is found.
>>
>> OK, but ->
>>
>>> Fixes: 94c6110b0b13 ("thermal/of: Use the .should_bind() thermal zone callback")
>>> Signed-off-by: Yu-Che Cheng <giver@chromium.org>
>>> ---
>>>   drivers/thermal/thermal_of.c | 3 ++-
>>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
>>> index 5ab4ce4daaeb..69c530e38574 100644
>>> --- a/drivers/thermal/thermal_of.c
>>> +++ b/drivers/thermal/thermal_of.c
>>> @@ -312,7 +312,8 @@ static bool thermal_of_should_bind(struct thermal_zone_device *tz,
>>>                                  break;
>>
>> -> I'd prefer to do a jump from here, that is
>>
>> -                                 break;
>> +                                goto put_cm_np;
>>>                  }
>>>
>>> -               break;
>>
>> and remove the break statement above altogether.
>>
>>> +               if (result)
>>> +                       break;
>>>          }
>>>
>>
>> And of course the label needs to be added too:
>>
>> +put_cm_np:
>>>          of_node_put(cm_np);
>>>
>>> ---
> 
> Or even, to avoid adding a new label, move the loop from
> thermal_of_should_bind() into a new function that will be called by it
> do carry out the cooling-maps lookup, like in the attached patch.
> 
> Can you check if it works for you, please?


I have experimented with your proposed patch with my DT setup.
It looks OK to me and much more clean.

If you have any super-edge-case scenario DT config to try, please let me
know. I will try to create such on my end...

If you would like to go forward with your patch, feel free to add:

Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>

Regards,
Lukasz