linux-kernel - Re: [PATCH v2 2/3] dt-bindings: power: Add mediatek larb definition

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: <c59f2f33-ad6b-469d-96be-9345920370b4@linaro.org>
Date: Wed, 27 Mar 2024 12:04:19 +0100
From: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To: Yu-chang Lee (李禹璋) <Yu-chang.Lee@...iatek.com>,
 MandyJH Liu (劉人僖) <MandyJH.Liu@...iatek.com>,
 "conor+dt@...nel.org" <conor+dt@...nel.org>,
 "robh@...nel.org" <robh@...nel.org>,
 "krzysztof.kozlowski+dt@...aro.org" <krzysztof.kozlowski+dt@...aro.org>,
 "matthias.bgg@...il.com" <matthias.bgg@...il.com>,
 "ulf.hansson@...aro.org" <ulf.hansson@...aro.org>,
 "angelogioacchino.delregno@...labora.com"
 <angelogioacchino.delregno@...labora.com>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "linux-mediatek@...ts.infradead.org" <linux-mediatek@...ts.infradead.org>,
 "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
 "linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
 Project_Global_Chrome_Upstream_Group
 <Project_Global_Chrome_Upstream_Group@...iatek.com>,
 Xiufeng Li (李秀峰) <Xiufeng.Li@...iatek.com>,
 "linux-arm-kernel@...ts.infradead.org"
 <linux-arm-kernel@...ts.infradead.org>, Fan Chen (陳凡)
 <fan.chen@...iatek.com>
Subject: Re: [PATCH v2 2/3] dt-bindings: power: Add mediatek larb definition

On 27/03/2024 11:56, Yu-chang Lee (李禹璋) wrote:
> On Wed, 2024-03-27 at 11:43 +0100, Krzysztof Kozlowski wrote:
>>  	 
>> External email : Please do not click links or open attachments until
>> you have verified the sender or the content.
>>  On 27/03/2024 11:39, Yu-chang Lee (李禹璋) wrote:
>>>>>>
>>>>> Hi,
>>>>>
>>>>> I will double check the format of yaml for the next version,
>> sorry
>>>> for
>>>>> inconvenience. But I did test it on mt8188 chromebook, the reason
>>>> why
>>>>
>>>> How do you test a binding on chromebook?
>>>>
>>>>> power domain need larb node is that when mtcmos power on, signal
>>>> glitch
>>>>> may produce. Power domain driver must reset larb when this happen
>>>> to 
>>>>> prevent dummy transaction on bus. That why I need larb node in
>> dts.
>>>>
>>>> No one talks here about larb node...
>>>
>>> Sorry, May you elaborate on what information I need to provide to
>> you
>>> or it is just a syntax problem I need to fix?
>>
>> Please explain the purpose of this property (how is it going to be
>> used by drivers)and what does it represent.
>>
> 
> It represent SMI LARB(Local ARBitration). In power domain driver when
> power on power domain, It need to reset LARB to prevent potential power
> glitch which may cause dummy transaction on bus. Without taking care of
> this issue it often leads to camera hang in stress test.

That sounds rather like missing resets... or something else connecting
these devices. Maybe the explanation is just imprecise...

Best regards,
Krzysztof