Re: [PATCH v4 01/10] dt-bindings: firmware: qcom: tmd: add TMD device type constants

Le 09/07/2026 à 09:37, Dmitry Baryshkov a écrit :
> On Thu, Jul 09, 2026 at 10:54:26AM +0530, Gaurav Kohli wrote:
>>
>>
>> On 7/8/2026 7:55 PM, Dmitry Baryshkov wrote:
>>> On Tue, Jul 07, 2026 at 03:55:13PM +0530, Gaurav Kohli wrote:
>>>>
>>>>
>>>> On 7/7/2026 1:04 AM, Dmitry Baryshkov wrote:
>>>>> On Mon, Jul 06, 2026 at 08:11:35PM +0200, Daniel Lezcano wrote:
>>>>>> On 7/6/26 19:47, Dmitry Baryshkov wrote:
>>>>>>> On Mon, Jul 06, 2026 at 07:03:18PM +0200, Daniel Lezcano wrote:
>>>>>>>> On 7/3/26 17:42, Dmitry Baryshkov wrote:
>>>>>>>>> On Fri, Jul 03, 2026 at 07:43:39PM +0530, Gaurav Kohli wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> On 7/3/2026 1:23 PM, Konrad Dybcio wrote:
>>>>>>>>>>> On 7/3/26 7:03 AM, Gaurav Kohli wrote:
>>>>>>>>>>>> Add Device Tree binding constants for Qualcomm Thermal Mitigation
>>>>>>>>>>>> Device (TMD) types used by remoteproc-backed thermal cooling devices.
>>>>>>>>>>>>
>>>>>>>>>>>> Qualcomm remote processors expose thermal mitigation endpoints
>>>>>>>>>>>> through QMI. These endpoints can be registered with the thermal
>>>>>>>>>>>> framework via the `#cooling-cells` property on the remoteproc node.
>>>>>>>>>>>>
>>>>>>>>>>>> The QMI TMD protocol identifies devices using string names (for example,
>>>>>>>>>>>> "pa", "modem", and "cdsp_sw"), while the DT cooling-device binding with
>>>>>>>>>>>> `#cooling-cells = <3>` requires numeric device id in the form:
>>>>>>>>>>>>
>>>>>>>>>>>>         <&phandle device_id min_state max_state>
>>>>>>>>>>>>
>>>>>>>>>>>> Define common TMD device index constants shared across currently
>>>>>>>>>>>> supported platforms. If a future target requires a different mapping,
>>>>>>>>>>>> additional target-specific constants can be introduced while preserving
>>>>>>>>>>>> existing DT ABI.
>>>>>>>>>>>>
>>>>>>>>>>>> Signed-off-by: Gaurav Kohli <[email protected]>
>>>>>>
>>>>>> [ ... ]
>>>>>>
>>>>>>>>> Why are you using only those TMD devices?
>>>>>>>>>
>>>>>>>>>> More constants can be added as needed.
>>>>>>>>>
>>>>>>>>> Kodiak is one of the supported platforms.
>>>>>>>>
>>>>>>>> What would be the benefit of having more than thirteen cooling devices
>>>>>>>> declared in the thermal framework and having only a couple of them mapped in
>>>>>>>> a thermal zone ?
>>>>>>>>
>>>>>>>> I agree there are more TMDs but if they are unused for the moment, why do we
>>>>>>>> need to add them ? Can we do that incrementally ?
>>>>>>>
>>>>>>> That's what I am trying to understand: why the implementation uses only
>>>>>>> the selected two devices, if the modem on Kodiak supports others. How
>>>>>>> can we find out, which TMDs to use on other devices.
>>>>>>
>>>>>> My understanding is that is an initial thermal setup. Gaurav will add them
>>>>>> step by step while setting up all the thermal zones instead of sending a big
>>>>>> patchset. And TBH, that will be much easier to review.
>>>>>
>>>>> In such a case it should be noted in the commit message and/or cover
>>>>> letter.
>>>>
>>>> Thanks for the review/guidance. Not all TMD endpoints are relevant for
>>>> kernel thermal zone binding — some like BCL and cold temperature are handled
>>>> from userspace when needed. The constants here cover only
>>>
>>> What if there is no userspace? Or the userspace is different from what
>>> you expect? I doubt we have TMD-speaking userspace yet.
>>
>> Thanks for mail, The TMD userspace implementation is available upstream at
>> https://github.com/qualcomm/qmi-framework.
> 
> Is it?
> 
> lumag@rohan:/tmp/qmi-framework$ git grep -i tmd
> lumag@rohan:/tmp/qmi-framework$
> 
> I found no traces of TMD there. Moreover, I don't see why QMI framework
> implementation would react to thermal events.
> 
>>>> what is needed for modem and CDSP thermal zones on the currently posted
>>>> targets.
>>>
>>> Again, SLPI, ADSP?
>>
>> Sorry, I should have said "generic subsystems" rather than listing specific
>> ones. SLPI and ADSP do not require active thermal mitigation on these
>> platforms.
> 
> Could you please provide details, then. What is cpuv_restriction_cold
> TMD?

It warms up the zone when the temperature is too cold