Re: [PATCH v2 1/5] dt-bindings: display: simple-framebuffer: Add interconnects property

["Luca Weiss" <luca.weiss@fairphone.com>]

Hi Krzysztof,

On Sun Jul 6, 2025 at 1:24 PM CEST, Dmitry Baryshkov wrote:
> On Wed, Jul 02, 2025 at 10:43:27PM +0200, Krzysztof Kozlowski wrote:
>> On 30/06/2025 10:40, Hans de Goede wrote:
>> >>
>> >> No one asks to drop them from the driver. I only want specific front
>> >> compatible which will list and constrain the properties. It is not
>> >> contradictory to your statements, U-boot support, driver support. I
>> >> really do not see ANY argument why this cannot follow standard DT rules.
>> > 
>> > So what you are saying is that you want something like:
>> > 
>> > framebuffer0: framebuffer@1d385000 {
>> > 	compatible = "qcom.simple-framebuffer-sm8650-mdss", "simple-framebuffer";
>> > }
>> > 
>> > and that the binding for qcom.simple-framebuffer-sm8650-mdss
>> > can then list interconnects ?
>> IMO yes (after adjusting above to coding style), but as mentioned in
>> other response you can just get an ack or opinion from Rob or Conor.
>
> But, this way we end up describing MDSS hardware block twice: once with
> the proper device structure and once more in the simple-framebuffer
> definition. I think this is a bit strange.
>
> I understand your point of having a device-specific compatible string
> and also having a verifiable schema, but I think it's an overkill here.
>
> Consider regulator supplies of this simple-framebuffer. Obviously some
> of them supply the panel and not the SoC parts. Should we also include
> the panel into the respective compat string? What about describing the
> device with two different DSI panels?
>
> I think this explodes too quickly to be useful. I'd cast my (small) vote
> into continuing using the simple-framebuffer as is, without additional
> compatible strings and extend the bindings allowing unbound number of
> interconnects.

How do we continue on this?

If the current solution is not acceptable, can you suggest one that is?

I'd like to keep this moving to not block the dts upstreaming
unnecessarily - or otherwise I need to drop simple-framebuffer from the
dts patch and keep this out-of-tree along with a patch like this.

Regards
Luca