Re: [PATCH v2 10/29] drm/sun4i: Rename DE2 registers related macros

[Maxime Ripard]

On Mon, Oct 08, 2018 at 04:28:41PM +0200, Jernej Åkrabec wrote:
> Dne ponedeljek, 08. oktober 2018 ob 12:18:28 CEST je Maxime Ripard napisal(a):
> > Hi,
> > 
> > On Sun, Oct 07, 2018 at 11:38:46AM +0200, Jernej Skrabec wrote:
> > > In preparation to introduce DE3 support, change prefix from "SUN8I_" to
> > > "DE2_". Current prefix suggest that it's valid only for one family,
> > > whereas in reality, DE2 unit is used also on sun50i family.
> > > Additionally, it will be easier to distinguish DE3 specific macros by
> > > using "DE3_" prefix.
> > > 
> > > No functional change in this commit.
> > 
> > I'm not too sure about this one. There's basically two ways to look at
> > this: you described the first one, and the second one would be to
> > treat it as we do for the compatibles: the IP was introduced on one
> > SoC family, and then got used on some other ones.
> > 
> > Trying to always match the one you have however have a quite big
> > maintainance cost, as can be shown by your patch: you always have to
> > adapt comments, function names, defines, etc. This creates a lot of
> > useless churns (ie, non-functional changes) in the drivers, that need
> > to be written in the first place, and then reviewed.
> > 
> > It's just not worth it.
> 
> Well, using family neutral way would mean that there is no need
> anymore for adaptation in the future, but as you wish.

If you consider only the DE case, where it has been numbered by
design, yes. If you consider all the other controllers that haven't
been (like, SPI, or the USB PHY, for example), then you end up with
two drivers that are using the same names, with no easy way to tell
which is which

> What prefix should I use for DE3 specific registers?

We should just follow the same pattern, and use the first family where
it was introduced. So sun50i, I guess?

Maxime

-- 
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

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