System software concall minutes - 2006-12-19

[Greg KH]

On Thu, Dec 21, 2006 at 01:07:50AM +0100, Carl-Daniel Hailfinger wrote:
> Hi Greg,
> 
> this discussion about device tree representation in /proc versus /sys
> came up during OLPC development discussions. A few words on the
> background: Linux has had OpenFirmware support for PowerPC for a long
> time. The OLPC machine is an AMD Geode (x86 arch) which uses LinuxBIOS
> with OpenFirmware.
> Since you're the sysfs and device tree expert and we want our kernel
> modifications to end up upstream, could you give some advice on the
> points below?

As it seems that Mitch has posted patches that create a separate
filesystem, I think this email is a bit late in my responding :)

> Mitch Bradley wrote:
> > Carl-Daniel Hailfinger wrote:
> >> Mitch Bradley wrote:
> >>  
> >>> Mitch:
> >>>  Code for device tree via /proc nearly ready
> >>
> >> Are you sure that you want to introduce new files in /proc which are
> >> not process-related? You will never get such a change merged upstream.
> >>   
> > I'm not sure of anything when it comes to Linux these days.  It seems
> > like everything is a political football.
> > 
> >> What speaks against /sys for that purpose?
> >>
> > The intention was to do /sys at some point, but we had a /proc example
> > in the PowerPC arch to use as a model.

Use /sys please if at all possible.

But I really don't know what your use of such a tree would be, to know
if sysfs is the proper place for it or not.  I suggest working with the
SPARC and ppc developers so we don't end up with 3 different
representations of OpenFirmware in the kernel at the same time.

good luck,

greg k-h