Re: [PATCH v2 1/4] drm/bridge: Add fwnode based helpers to get the next bridge

[Sui Jingfeng]

Hi,


On 2024/3/9 18:39, Dmitry Baryshkov wrote:
> On Sat, 9 Mar 2024 at 11:33, Sui Jingfeng <sui.jingfeng@xxxxxxxxx> wrote:
> > Hi,
> >
> >
> > On 2024/3/8 04:40, Dmitry Baryshkov wrote:
> > > > > But really, there is nothing so hard about it:
> > > > > - Change of_node to fw_node, apply an automatic patch changing this in
> > > > > bridge drivers.
> > > > > - Make drm_of_bridge functions convert passed of_node and comp
> > > > >
> > > > > After this we can start cleaning up bridge drivers to use fw_node API
> > > > > natively as you did in your patches 2-4.
> > > > Yes, it's not so hard. But I'm a little busy due to other downstream developing
> > > > tasks. Sorry, very sorry!
> > > >
> > > > During the talk with you, I observed that you are very good at fwnode domain.
> > > > Are you willing to help the community to do something? For example, currently
> > > > the modern drm bridge framework is corrupted by legacy implement, is it possible
> > > > for us to migrate them to modern? Instead of rotting there? such as the lontium-lt9611uxc.c
> > > > which create a drm connector manually, not modernized yet and it's DT dependent.
> > > > So, there are a lot things to do.
> > > Actually, lontium-lt9611uxc.c does both of that 😉 It supports
> > > creating a connector and it as well supports attaching to a chain
> > > without creating a connector. Pretty nice, isn't it?
> >
> > But why the drm_bridge_connector helpers and/or the drm_connector bridge can't suit you need?
> > Coding this way just add boilerplate into drm bridge subsystem, right?
> Because there are platforms, like iMX LCDIF which can use the
> lt9611uxc bridge, but do not make use of the drm_bridge_connector yet.

Well, I have just grepped across the drm-tip kernel branch, but I don't find
iMX LCDIF you mentioned. See the search results pasted at bellow.


$ find . -name "*.dts" -type f | xargs grep "lontium,lt9611uxc"
/arm64/boot/dts/qcom/sm8450-hdk.dts:		compatible = "lontium,lt9611uxc";
/arm64/boot/dts/qcom/qrb5165-rb5.dts:		compatible = "lontium,lt9611uxc";
/arm64/boot/dts/qcom/qrb2210-rb1.dts:		compatible = "lontium,lt9611uxc";
/arm64/boot/dts/qcom/qrb4210-rb2.dts:		compatible = "lontium,lt9611uxc";
/arm64/boot/dts/qcom/sm8350-hdk.dts:		compatible = "lontium,lt9611uxc";


So I can't see the drm driver that you refer to, can you pointed it out for study
purpose? Even it's exist, however, back to that time, why don't you posting a patch
to switch it to the canonical design as you mentioned and give the community a clean
design?
 
And those are just *reasons*, from the viewpoint of the *result*.
The merged patch results in a 'side-by-side' implement and boilerplate added
into drm bridges subsystem, the results doesn't change no matter what the
reason is, right?