Re: [PATCH v2 02/10] hwmon: Add Qualcomm PMIC BCL driver

Daniel Lezcano <[email protected]> Thu, 30 Jul 2026 13:48:02 +0200
Newsgroups org.kernel.vger.linux-hwmon,dev.linux.lists.mfd,org.kernel.vger.linux-arm-msm,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-kernel
Message-ID <[email protected]>
On 7/24/26 02:04, Guenter Roeck wrote:
> On 7/23/26 12:16, Manaf Meethalavalappu Pallikunhi wrote:
>> Hi Guenter,
>>
>> On 7/23/2026 12:29 AM, Guenter Roeck wrote:
>>> On 7/22/26 11:19, Manaf Meethalavalappu Pallikunhi wrote:
>>>> Hi Guenter,
>>>>
>>>> On 7/22/2026 11:16 PM, Guenter Roeck wrote:
>>>>> On 7/22/26 10:38, Manaf Meethalavalappu Pallikunhi wrote:
>>>>> ...
>>>>>>>
>>>>>>> I am curious: Why not use static initialization and use the 
>>>>>>> is_visible
>>>>>>> function to determine if an attribute is visible or not ?
>>>>>>
>>>>>> ACK. There is already a comment in v1 suggesting the use of 
>>>>>> dynamic allocation based on the available attributes rather than 
>>>>>> static initialization. The intent is to avoid having to perform 
>>>>>> enable flag checks in multiple places.
>>>>>> . >
>>>>>
>>>>> You lost me, sorry. There is only a single is_visible function,
>>>>> and its intent is exactly to handle situations where some sensors
>>>>> are not always available.
>>>>>
>>>>> What would be those "multiple places" ?
>>>>
>>>> Understood, thanks for the clarification. I'll revert to static 
>>>> attribute initialization in the next revision and use is_visible() 
>>>> to control attribute visibility where needed.
>>>>
>>>>>
>>>>>>>  From the earlier exchange I had the impression that there is a 
>>>>>>> large
>>>>>>> number of current and voltage channels, but it looks like there 
>>>>>>> is only
>>>>>>> one each. That doesn't really warrant or need all this dynamic code
>>>>>>
>>>>>> Yes, this hardware only supports one or two channels (voltage and 
>>>>>> current). What we discussed earlier was that each channel can have 
>>>>>> up to three threshold alarms (warning, critical, and emergency). 
>>>>>> However, the hwmon framework currently supports only two limit 
>>>>>> alarms for these sensor types. I have not added support for the 
>>>>>> third alarm threshold in this series to keep the initial driver 
>>>>>> support aligned with the existing hwmon capabilities. Once the 
>>>>>> basic driver support is accepted, I can queue a follow-up series 
>>>>>> to add support for the third limit alarm.
>>>>>>
>>>>>
>>>>> What does that have to do with attribute visibility ?
>>>>
>>>> I was only clarifying that the channel count has always been small 
>>>> (maximum of two channels) and has not changed since v1. The earlier 
>>>> discussion was primarily around the limit alarm attributes. That 
>>>> said, you're right that this is unrelated to attribute visibility.
>>>>
>>>
>>> Feel free to use (and test)
>>> https://lore.kernel.org/linux-hwmon/20260722185749.2313572-1- 
>>> [email protected]/T/#u
>>
>> Thanks for working on this. I'll use that change as the base, rebase 
>> my series on top of it, and add support for the third alarm level.
>> By the way, for the voltage channel, the hardware monitors 
>> undervoltage conditions and provides three threshold levels. At the 
>> moment, I am mapping:
>>
>> LVL0 → min
>> LVL1 → lcrit
>>
>> For LVL2, would it be possible to introduce a corresponding low- 
>> voltage emergency threshold, such as lemergency (or another more 
>> appropriate name), to represent the third alarm level for voltage 
>> sensors ?
>>
> 
> We can, but I really have no idea how to name it. lcrit is bad enough,
> but lemergency is even worse (or at least I think so). "lemerg" would
> be almost as bad, but at least it would kind of match "lcrit".
> I tried to ask Google AI, but it didn't give me any useful ideas.
> Any other suggestions or ideas ?

'lfatal' ?