Re: [RFC PATCH 1/3] devicetree: bindings: dsiplay: panel: panel-simple.yaml: Add Raspberry pi dsi panel compatible

[Rob Herring <robh@kernel.org>]

On Tue, Aug 19, 2025 at 11:22:42AM +0530, Kumar, Udit wrote:
> 
> On 8/19/2025 10:46 AM, Raghavendra, Vignesh wrote:
> > 
> > On 8/19/2025 10:24 AM, Kumar, Udit wrote:
> > > On 8/18/2025 9:17 PM, Harikrishna Shenoy wrote:
> > > > Add RPi DSI panel[0] as a valid compatible for simple-panel.
> > > > 
> > > > [0]: https://www.raspberrypi.com/products/raspberry-pi-touch-display/
> > $subject has typo s/dsiplay/display and s/dsi/DSI
> > (use a spellcheck with your editor).
> > 
> > Also follow the existing prefix convention for the file (run
> > git log --oneline to figure out the right prefix)
> > 
> > > > Signed-off-by: Harikrishna Shenoy <h-shenoy@ti.com>
> > > > ---
> > > >    .../devicetree/bindings/display/panel/panel-simple.yaml         | 2 ++
> > > >    1 file changed, 2 insertions(+)
> > > > 
> > > > diff --git a/Documentation/devicetree/bindings/display/panel/panel-
> > > > simple.yaml b/Documentation/devicetree/bindings/display/panel/panel-
> > > > simple.yaml
> > > > index 1ac1f0219079..65f486f2bc9d 100644
> > > > --- a/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
> > > > +++ b/Documentation/devicetree/bindings/display/panel/panel-simple.yaml
> > > > @@ -268,6 +268,8 @@ properties:
> > > >          - rocktech,rk070er9427
> > > >            # Rocktech Display Ltd. RK043FN48H 4.3" 480x272 LCD-TFT panel
> > > >          - rocktech,rk043fn48h
> > > > +        # Raspberry, 7" dsi panel
> > > > +      - rpi,7inch-dsi
> > > Hello Hari,
> > > 
> > > Driver changes should come first to match new compatible before device
> > > tree changes.
> > No, there isnt a driver update that I can see in the current series. But
> 
> correct current series does not have driver changes.
> 
> I would expect driver changes as well, which should come before device tree.

If you rely on that, then you are likely breaking the ABI. Please don't 
submit any DT related patches until you understand that.

You must define the ABI first, then add users of that ABI. Users are 
both .dts files and drivers. It is that simple.

Rob