removing get_immrbase()??

[Kumar Gala]

On Apr 22, 2009, at 11:06 PM, David Gibson wrote:

> Well, yes, I guess I agree.  How immutable you consider the device
> tree blob to be is a judgement call based on the specific details of
> platform/board in question.  If it is indeed a reference platform, in
> the early stages of development where it's reasonably easy to change
> the dtb, then it's probably best to change the dtb in sync with the
> kernel to reduce long-term cruft build-up.  But once the board is
> sufficiently widely deployed, you want to stop doing that and include
> backwards compatibility workarounds in the kernel to cope with the
> widely deployed broken trees.

I disagree with the point about providing workarounds to cope w/ 
deployed device trees (at least for the problems I'm thinking off in  
which nodes didn't exist).  This just sounds like double work and is a  
disincentive to actually making such changes.

Lets say I had an error driver for our MCM (core to soc coherency  
module).  It was getting the base address by using get_immrbase().   
Today I proposed a proper device node for the MCM block as it doesn't  
exist in .dts today.  We add such a node into .dts and I can clean up  
my error driver to use proper device node information.  However I've  
just broken any old .dts that didn't have this node.  You are saying I  
need to add code into the kernel to create this new node and we have  
to keep that code around for ever in the kernel.. why would I ever  
bother to actually changing anything than.

- k