Re: [PATCH 1/2] mmc: add Device Tree properties for UHS modes

[Pawel Moll <pawel.moll@arm.com>]

On Mon, 2013-07-29 at 08:18 +0100, Guennadi Liakhovetski wrote:
> A short addendum. At least with Renesas SoCs I see the situation in the 
> following way: new SoC versions appear relatively frequently. 

What frequency are we talking about? Once per year? Once per month? I'm
not trying to be picky, it really makes a difference...

> With compatibility strings we have to change _all_ Renesas drivers for _each_ 
> SoC version even if just to add a new struct of_device_id entry. This 
> doesn't seem very productive to me.

There is at least precedence in the MMC world - have a look at
drivers/mmc/host/mmci.c and the struct variant_data... There seem to be
a new variant every 6 months or so (I must admit guilt of of making some
of them ;-) coming from two different companies.

And although it's a primecell (aka amba_bus) device, so the compatibilty
string remains the same, the struct amba_id was being extended every
time which is pretty much the same thing.

Pawel

PS. Having said all that I'm hoping the MMCI evolution has finally
stopped so no new variants will be needed ;-)