Re: removing get_immrbase()??

[David Gibson <david@gibson.dropbear.id.au>]

On Thu, Apr 23, 2009 at 07:53:11AM -0600, Grant Likely wrote:
> On Wed, Apr 22, 2009 at 3:31 PM, Kumar Gala <galak@kernel.crashing.org> wrote:
> >
> > On Apr 22, 2009, at 3:16 PM, Timur Tabi wrote:
> >
> >> Scott Wood wrote:
> >>>
> >>> Timur Tabi wrote:
> >>>>>
> >>>>>      these two are related and seem like we could look for "fsl,cpm2"
> >>>>
> >>>> That's okay, as long as you don't break compatibility with older
> >>>> device trees that don't have that property, unless you can demonstrate
> >>>> that these trees would never work with the current kernel anyway.
> >>>
> >>> All CPM2 device trees should have fsl,cpm2 listed in the compatible of
> >>> the CPM node.
> >>
> >> Yes, but did they always have that compatible field?  I'm concerned
> >> about situations where someone updates his kernel but not his device
> >> tree.  This is a scenerio that we always need to try to support.
> >
> > I disagree.  If you update your kernel you should update your device tree
> > (thus we have .dts in the kernel tree and not somewhere else).
> 
> Not always possible.  The device tree may be 'softer' than firmware,
> and easier to update, but it is still firmer than the kernel.  That
> is

Again, this is not inherent, it's a platform design choice.  It's this
way for modern u-boot, but not for all platforms.

> why so much effort has been spent to not break compatibility with
> older device trees.

-- 
David Gibson			| I'll have my music baroque, and my code
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