linux-kernel - Re: [PATCH v2 6/8] dt-bindings: soc: qcom: pmic-glink: Move X1E80100 out of fallbacks

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <bcf487c9-e522-44a3-b094-daf98823a195@kernel.org>
Date: Tue, 3 Jun 2025 09:06:20 +0200
From: Krzysztof Kozlowski <krzk@...nel.org>
To: Fenglin Wu <fenglin.wu@....qualcomm.com>,
 Sebastian Reichel <sre@...nel.org>, Bjorn Andersson <andersson@...nel.org>,
 Konrad Dybcio <konradybcio@...nel.org>, Rob Herring <robh@...nel.org>,
 Krzysztof Kozlowski <krzk+dt@...nel.org>, Conor Dooley
 <conor+dt@...nel.org>, Heikki Krogerus <heikki.krogerus@...ux.intel.com>,
 Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc: Subbaraman Narayanamurthy <subbaraman.narayanamurthy@....qualcomm.com>,
 David Collins <david.collins@....qualcomm.com>, linux-pm@...r.kernel.org,
 linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org,
 kernel@....qualcomm.com, devicetree@...r.kernel.org,
 linux-usb@...r.kernel.org
Subject: Re: [PATCH v2 6/8] dt-bindings: soc: qcom: pmic-glink: Move X1E80100
 out of fallbacks

On 03/06/2025 08:59, Fenglin Wu wrote:
> 
> On 6/3/2025 2:47 PM, Krzysztof Kozlowski wrote:
>> On 03/06/2025 08:42, Fenglin Wu wrote:
>>> On 6/2/2025 3:40 PM, Krzysztof Kozlowski wrote:
>>>> On 30/05/2025 09:35, Fenglin Wu via B4 Relay wrote:
>>>>> From: Fenglin Wu <fenglin.wu@....qualcomm.com>
>>>>>
>>>>> Move X1E80100 out of the fallbacks of SM8550 in pmic-glink support.
>>>> Why?
>>>>
>>>> Do not describe what you do here, it's obvious. We see it from the diff.
>>>>
>>>>
>>>> Best regards,
>>>> Krzysztof
>>> Previously, in qcom_battmgr driver, x1e80100 was specified with a match
>>> data the same as sc8280xp, also sm8550 was treated a fallback of sm8350
>>> without the need of a match data.
>>>
>>> In ucsi_glink driver, sm8550 had a match data and x1e80100 was treated
>>> as a fallback of sm8550. There was no issues to make x1e80100 as a
>>> fallback of sm8550 from both qcom_battmgr and ucsi_glink driver perspective.
>>>
>>> In patch [5/8] in this series, in qcom_battmgr driver, it added charge
>>> control functionality for sm8550 and x1e80100 differently hence
>>> different match data was specified for them, and it makes x1e80100 ad
>>> sm8550 incompatible and they need to be treated differently.
>> So you break ABI and that's your problem to fix. You cannot make devices
>> incompatible without good justification.
> 
> I would say x1e80100 and sm8550 are different and incompatible from a 
> battery management firmware support perspective. The x1e80100 follows 
> the sc8280xp as a compute platform, whereas the sm8550 follows the 
> sm8350 as a mobile platform.

Not correct arguments for compatibility.

> 
> The difference between them was initially ignored because the sm8550 
> could use everything that the sm8350 has, and no match data needed to be 
> specified for it. However, now the sm8550 has new features that the 
> sm8350 doesn't have, requiring us to treat it differently, thus the 
> incompatibility was acknowledged.

So they are perfectly compatible.

I really do not understand what we are discussing here. Explain in
simple terms of DT spec: what is incompatible that SW cannot use one
interface to handle the other?


Best regards,
Krzysztof