Re: [PATCH] devicetree - document using aliases to set spi bus number.

From: Rob Herring
Date: Wed May 25 2016 - 13:49:40 EST

On Tue, May 24, 2016 at 04:34:50PM -0700, Frank Rowand wrote:
> On 5/24/2016 11:32 AM, Mark Brown wrote:
> > On Tue, May 24, 2016 at 08:03:48PM +0200, Christer Weinigel wrote:
> >> On 05/24/2016 07:20 PM, Mark Brown wrote:
> >
> >>> I'm not sure this is something we want to support at all, I can't
> >>> immediately see anything that does this deliberately in the SPI
> >>> code and obviously the "bus number" is something of a Linux
> >>> specific concept which would need some explanation if we were going
> >>> to document it. It's something I'm struggling a bit to see a
> >>> robust use case for that isn't better served by parsing sysfs,
> >>> what's the goal here?
> >
> >> If this isn't something that should be in the Documentation/devicetree
> >> because it's not generig enough, where should Linux-specific
> >> interpretations such as this be documented?
> >
> > I'm not clear that we want to document this at all since I am not clear
> > that there is a sensible use case for doing it. I did ask for one but
> > you've not articulated one in this reply. I am much less gung ho than
> > Grant on this one, even as a Linux specific interface it seems very
> > legacy.

No, we don't.

> >
> The time for the use case was when the patch was accepted.

Ideally, yes, but things getting missed in review or later deciding
things were a bad idea can always be debated again.

> It is in the kernel, it is appropriate to document it.

Things get undocumented all the time when we deprecate them.