Re: [PATCH] arm64: dts: qcom: sm8550-qrd: add display and panel

[Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>]

On 16/05/2023 17:36, Konrad Dybcio wrote:
>>>> But don't we want to disable both when display is not used (not connected)?
>>> The MDSS bus device only has a 0x1000 slice of the 0x90000-long "full MDSS",
>>> the rest is probed with MDP/DPU. It also calls of_something_populate that
>>> make DSI, DSIPHY and DP/HDMI probe. But all of them ultimately need a graph
>>> handle to MDP.
>>>
>>> If we have a display (of any kind), MDP has to be enabled (or the display
>>> engine will not have a way to be programmed).
>>>
>>> If we don't, enabling MDSS makes no sense as all of the hardware will be
>>> shut down right after probing.
>>>
>>> So I'd say either both or none.
>>
>> Yes, so the current state - both disabled - is matching it.
> Right, but what i was trying to say is that if we leave MDP without
> any status properties, it will follow MDSS.

Ah, I missed that it is MDSS child, so indeed there is no point to have
it explicitly disabled. I'll fix it.

Best regards,
Krzysztof