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

[Guennadi Liakhovetski <g.liakhovetski@gmx.de>]

On Mon, 29 Jul 2013, Pawel Moll wrote:

> 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...

Definitely not every month - not until now in the mainline at least. I 
currently count 9 SoCs, added since 2010, which makes about 2-3 SoCs per 
year.

Thanks
Guennadi

> > 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 ;-)

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
http://www.open-technology.de/