Re: [PATCH 3/4] dt-bindings: drm/bridge: anx7625: Change bus-type to 7 (DPI)

From: Robert Foss <robert.foss@linaro.org>
To: Xin Ji <xji@analogixsemi.com>
Cc: Rob Herring <robh@kernel.org>,
	Andrzej Hajda <andrzej.hajda@intel.com>,
	Neil Armstrong <narmstrong@baylibre.com>,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Jonas Karlman <jonas@kwiboo.se>,
	Jernej Skrabec <jernej.skrabec@gmail.com>,
	David Airlie <airlied@linux.ie>, Daniel Vetter <daniel@ffwll.ch>,
	bliang@analogixsemi.com, qwen@analogixsemi.com,
	dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 3/4] dt-bindings: drm/bridge: anx7625: Change bus-type to 7 (DPI)
Date: Wed, 13 Apr 2022 16:28:51 +0200	[thread overview]
Message-ID: <CAG3jFyt1Srtn2aTFQ6b8Rxc6F_GCzU2mKxiEiWwgskMwHHjj5Q@mail.gmail.com> (raw)
In-Reply-To: <20220409044740.GA595530@anxtwsw-Precision-3640-Tower>

On Sat, 9 Apr 2022 at 06:47, Xin Ji <xji@analogixsemi.com> wrote:
>
> On Mon, Apr 04, 2022 at 12:52:14PM -0500, Rob Herring wrote:
> > On Mon, Mar 28, 2022 at 08:09:54PM +0800, Xin Ji wrote:
> > > Change bus-type define for DPI.
> > >
> > > Fixes: a43661e7e819 ("dt-bindings:drm/bridge:anx7625:add vendor define")
> > >
> > > Signed-off-by: Xin Ji <xji@analogixsemi.com>
> > > ---
> > >  .../devicetree/bindings/display/bridge/analogix,anx7625.yaml  | 4 ++--
> > >  1 file changed, 2 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml b/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
> > > index 0d38d6fe3983..4590186c4a0b 100644
> > > --- a/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
> > > +++ b/Documentation/devicetree/bindings/display/bridge/analogix,anx7625.yaml
> > > @@ -106,7 +106,7 @@ properties:
> > >                remote-endpoint: true
> > >
> > >                bus-type:
> > > -                enum: [1, 5]
> > > +                enum: [7]
> >
> > Changing is an ABI break, but didn't we revert adding this?
> Hi Rob, sorry, what do you mean about ABI break? Do I need remove this
> patch in this serial? Or do I need revert patch
> https://patchwork.freedesktop.org/patch/462331/, I don't know how to do
> it.
>

I contributed to the confusion about this, let's see if we can clear it up.

An issue was found related to which enum values were used to represent
what late in the last release cycle. As a result a revert[1] patch for
everything touching bus-type in anx7625 was merged.

This patch, does not apply to drm-misc-next due to the revert, and if
Xin Ji rebases his work on the drm-misc-next there should be no
ABI-change as this patch when fixed up will introduce bus-type to the
nax7625 ABI.

Xin: Does this make sense to you?

[1] https://cgit.freedesktop.org/drm/drm-misc/commit/?id=979452fbc43028675b5a5da156f91928b739dea8