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

[Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>]

Le 09/07/2026 à 09:58, Dmitry Baryshkov a écrit :
> On Thu, Jul 09, 2026 at 09:42:04AM +0200, Daniel Lezcano wrote:
>>
>>
>> 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 <gaurav.kohli@oss.qualcomm.com>
>>>>>>>>
>>>>>>>> [ ... ]
>>>>>>>>
>>>>>>>>>>> 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
> 
> So, if we ever get back to supporting warming up, these TMDs would
> become relevant. Am I right?
Probably

Can we do some progress with these TMDs definition ?

Spending 95% of the effort to discuss 1% of the proposed changes, which 
is always DT discussion, is quite frustrating :/

You want to add all defines for existing TMDs for all platforms ?

We are talking about numerical values right ? Why is it a problem to add 
their define later ?