Re: [PATCH 1/6] dt-bindings: display: Add panel-mipi-dsi-bpf generic panel binding

[Maxime Ripard]

On Wed, Sep 30, 2026 at 02:07:39PM -0500, Rob Herring wrote:
> On Wed, Sep 30, 2026 at 3:04 AM Maxime Ripard <mripard@xxxxxxxxxx> wrote:
> >
> > On Tue, Sep 29, 2026 at 05:28:22PM -0500, Rob Herring wrote:
> > > On Tue, Sep 29, 2026 at 10:39:24AM +0200, Maxime Ripard wrote:
> > > > On Mon, Sep 28, 2026 at 03:40:59PM -0500, Rob Herring wrote:
> > > > > On Mon, Sep 28, 2026 at 06:22:01PM +0200, Maxime Ripard wrote:
> > > > > > Most MIPI-DSI panel drivers follow an identical pattern: acquire
> > > > > > regulators and GPIOs, perform a reset pulse with specific timing,
> > > > > > send a vendor-supplied sequence of DSI commands, then enable the
> > > > > > display. The only truly panel-specific part is the init sequence
> > > > > > and power-on/off timing.
> 
> [snip a bunch of irrelevant shit]
> 
> > > > So, let's phrase this differently: what's different about the
> > > > description than panel-mipi-dsi-spi, or any other binding already in
> > > > tree?
> > >
> > > There's all of 3 panels supported. Compared to all the other panels we
> > > have, hardly the rule over the exception. You can always fine "bad"
> > > examples or exceptions.
> > >
> > > That one defines a single supply. Any other MIPI SPI panel with
> > > different supplies or GPIO controls probably has its own binding. Trying
> > > to parameterize that in DT doesn't work. We've rejected trying to do
> > > that in DT over and over. What's your story here for that?
> >
> > Sigh... Look, I really don't care about an argument DT maintainers use
> > at their discretion for this. We both know full well that it's been and
> > still is inconsistenly applied, and you also know that it's not like
> > I've been playing the DT game since pretty much the beginning (on ARM
> > anyway). So it's not like I don't want to make it work, I do. But what I
> > care about is enabling that driver to work.
> >
> > I reused exactly the same binding than the last major binding that was
> > merged for panels, and support about the same number of panels. I guess
> > that was a mistake, so sorry for that.
> >
> > I'm fine with reworking the binding any way you want as long as it still
> > allows for the same use-case, but I would have hoped for a better
> > feedback on how to do so than "oh what a huge pile of shit this is".
> 
> When you can answer my question above rather than make up shit I
> didn't say, maybe I'll reply again on this thread. Otherwise I'm done
> here. I don't need this abuse for the thankless job of DT
> maintainership.

It's been the whole tone of the reviews, so I'm sorry if you were caught
in the crossfire and you didn't mean that. And I'm sorry it made your DT
maintainership work harder than it already is.

I do mean what I said before though. I have no problem changing the
binding the way you want, but I need to know what to change in the first
place, otherwise it's really no better than a NAK, or we're bound to
have the same exchange for the v2, and I'd rather not.

I indeed missed your question, but now I'm not sure I understand what
you mean by "paremeterize that in DT"? The supplies in the binding are
an aggregate of all the possible supplies a panel can take. They are not
a wildcard, but they all have their own semantics that are used by
panels right now.

I don't expect any new supply to be introduced, unless there's a major
panel technology change such as the one we had with the introduction of
OLED.

Would you prefer to reduce the number of supplies to the minimum we need
right now, and extend it as needed?

Maxime

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