linux-kernel - Re: [PATCH v4 09/12] arm64: dts: qcom: sdm845-lg-common: Add camera flash

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: <d8a3a30a-d627-4085-bab0-b73a2eeaa12b@oss.qualcomm.com>
Date: Thu, 4 Dec 2025 10:17:01 +0100
From: Konrad Dybcio <konrad.dybcio@....qualcomm.com>
To: Paul Sajna <sajattack@...tmarketos.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>, David Heidelberg <david@...t.cz>
Cc: linux-arm-msm@...r.kernel.org, devicetree@...r.kernel.org,
        linux-kernel@...r.kernel.org, phone-devel@...r.kernel.org,
        Amir Dahan <system64fumo@...tonmail.com>,
        Christopher Brown <crispybrown@...il.com>
Subject: Re: [PATCH v4 09/12] arm64: dts: qcom: sdm845-lg-common: Add camera
 flash

On 12/3/25 10:27 AM, Paul Sajna wrote:
> linux-postmarketos-qcom-sdm845-6.16.7_p20251203010632-r0.apk
> 
> 
> December 1, 2025 at 11:42 AM, "Konrad Dybcio" <konrad.dybcio@....qualcomm.com mailto:konrad.dybcio@....qualcomm.com?to=%22Konrad%20Dybcio%22%20%3Ckonrad.dybcio%40oss.qualcomm.com%3E > wrote:
> 
> 
>>
>> On 11/28/25 9:20 PM, Paul Sajna wrote:
>>
>>>
>>> I did more testing on this, and the led only comes on if it's brightness is set to approx 150/255 or lower. In that case, should I set led-max-microamp to 60mA?
>>>
>> FWIW your downstream kernel sets up channels 0 and 1, here you only
>> enabled 1. Taking a look at a picture of the phone, I only see a single
>> LED on the back, so perhaps you're (over)driving a single power line?
>>
>> I'm not a milion percent sure, but I would assume the current draw
>> *limiting* register applies to the sum of the current going through
>> the three channels because there's only a single instance of it.
>>
>> Konrad
>>
> 
> I tried setting up both, but only the one that was mapped as `led-sources = <2>` seemed to have any effect. Also it would confuse userspace flashlight apps if there were two I think. So I'll push v5 with just the one that does anything.

led-sources is parsed into a bitmap and written into REG_MODULE_EN,
this doesn't translate into anything that's userspace-visible

That would instead be the case if you defined a pair of LEDs under
the device node (which is valid if there's two separate ones, such
as for some phones with a back and front LED flash)

Konrad