Re: [PATCH 0/2] qcom_battmgr: Add batteryless DC-adapter MAINS support

[Krzysztof Kozlowski <krzk@kernel.org>]

On 02/07/2026 13:17, Rakesh Kota wrote:
> On Tue, Jun 30, 2026 at 04:16:13PM +0200, Konrad Dybcio wrote:
>> On 5/22/26 12:56 AM, Bjorn Andersson wrote:
>>> On Tue, May 19, 2026 at 12:29:38PM +0530, Rakesh Kota wrote:
>>>> On Mon, May 18, 2026 at 04:36:32PM +0200, Konrad Dybcio wrote:
>>>>> On 5/18/26 3:49 PM, Rakesh Kota wrote:
>>>>>> On batteryless boards powered by 12V DC adapters, registering the
>>>>>> power supply as BATTERY causes userspace to incorrectly trigger
>>>>>> battery power-saving sequences.
>>>>>
>>>>> Does battman really offer no way of differentiating whether a battery
>>>>> is *actually* present in such cases?
>>>>>
>>>>> What boards are affected?
>>>>>
>>>> Currently, batteryless support is only implemented for the
>>>> qcs6490-rb3gen2(Kodiak) board.
>>>>
>>>
>>> What do you mean?
>>>
>>> Are you saying that the pmic_glink firmware in Kodiak has a one-off hack
>>> that no other implementation of this firmware has?
>>>
>>> My Lenovo IdeaCentre (hamoa) doesn't have battery, what should I do now?
>>
>> I was going through my inbox.
>> This remains unanswered, and I don't see the discussion progressing
>> without resolving this.
>>
> To clarify — there is no platform-side hack involved. The Kodiak board
> has a batteryless variant, but the pmic_glink firmware provides no way
> to distinguish whether a battery is physically present or not. Since
> this can't be determined from firmware, we introduced a DT-based
> property to describe the hardware configuration explicitly.
> 
> This is not Kodiak-specific — any batteryless board, including hamoa,
> can use the same DT property to avoid incorrect BATTERY registration

Unfortunately the answer might be: fix your firmware. Since your
firmware is the interface and we do not expose battery in DT, then you
do not get additional properties. You made conscious design choice of
abstracting some things in the firmware, so you do control that part of
the software stack. If you make one choice, it might lead to other, like
rejecting such properties.

Best regards,
Krzysztof