Re: [PATCH] drm: don't link DP aux i2c adapter to the hardware device node

[Lucas Stach <l.stach@pengutronix.de>]

Hi Rob,

Am Mittwoch, den 29.03.2017, 08:56 -0500 schrieb Rob Herring:
> On Mon, Jan 23, 2017 at 10:33 AM, Thierry Reding
> <thierry.reding@gmail.com> wrote:
> > On Fri, Jan 13, 2017 at 06:36:30PM +0100, Lucas Stach wrote:
> >> The i2c adapter on DP AUX is purely a software construct. Linking
> >> it to the device node of the parent device is wrong, as it leads to
> >> 2 devices sharing the same device node, which is bad practice, as
> >
> > Who says that two devices can't share the same device node? It's done
> > all the time.
> 
> It's done *some of the time* and I would not consider it best practice.
> 
> >> well as the i2c trying to populate children of the i2c adapter by
> >> looking at the child device nodes of the parent device.
> >
> > A set of patches landed in v4.9 to work around this issue in a better
> > way. See:
> >
> >         98b00488459e dt-bindings: i2c: Add support for 'i2c-bus' subnode
> >         7e4c224abfe8 i2c: core: Add support for 'i2c-bus' subnode
> 
> What does this buy us? I don't see why this needs to be in DT either.
> Contrary to popular belief, DT is not the only way to instantiate
> devices, C code can still do it.
> 
> Also, if this one line removal has no side effects, then how was it
> even needed? We can always add it back if there's some argument for
> why it is needed.

Okay, so I take this as you mostly agreeing with the rationale of this
patch.

@Daniel or someone with drm-misc commit rights: could you please pull
this in if you are fine with it?

Regards,
Lucas

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