Re: [PATCH] arm64: dts: qcom: sdm845-oneplus: add panel rails to simplefb

[Konrad Dybcio]

On 6/20/26 1:15 AM, Sam Day wrote:
> Hello Konrad,
> 
> On Saturday, 20 June 2026 at 1:11 AM, Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxxxx> wrote:
> 
>> On 6/16/26 7:27 AM, Sam Day via B4 Relay wrote:
>>> From: Sam Day <me@xxxxxxxxxxx>
>>>
>>> These regulators are marked regulator-boot-on, but that doesn't
>>> guarantee they'll stay alive as long as the simplefb does. Adding the
>>> explicit supplies ensures that booting with MDSS disabled doesn't
>>> switch the panel off 30 seconds after boot.
>>
>> Why would you boot without MDSS if you want the panel to function?
> 
> For my particular use-case [1] I'm trying to avoid taking over the display
> hardware entirely, and use simplefb until kexecing into the real kernel. In
> this case the user might halt in a pre-boot menu UI for a while.
> 
> I can also imagine this being similarly useful for "recovery kernel" use-cases
> where again, it may not be desirable to assume control of MDSS/MDP/DSI blocks.
> 
> [1]: https://github.com/samcday/pocketboot

Can you handle this by adding a panel = <&display_panel> property
under simplefb, pointing to the display panel defined in the same
file?

Konrad