[Cbe-oss-dev] [RFC,PATCH 1/1] Allow PCAB to boot Linux 2.6.19

[Benjamin Herrenschmidt]

On Wed, 2006-11-15 at 18:17 +0100, Jean-Christophe Dubois wrote:
> SLOF on FACB/PCAB/CAB still has a quite mixed up device tree. The latest patch 
> for 2.6.19 will not allow linux to boot on the PCAB as it will try to access 
> the Axon MPIC with the ioremap method (instead of the DCR method) but it is 
> then missing the 16 bytes striding info to go with it.

The device-tree needs fixing then :-)

> This patch allow the PCAB to boot 2.6.19 with Arnd patches from November 11th.

Well, I implemented the native DCR support in MPIC to avoid having to do
that ... 

> Note that unfortunately the MPIC controller info is present twice in the 
> actual PCAB device tree. Therefore the MPIC is initialized twice. Once with 
> the ioremap method and once with the DCR method. It is obviously not really 
> the best thing.
> 
> A cleaner method would be to update SLOF on FCAB/PCAB/CAB so that it is at the 
> same level as the Malta blade but we are not here yet.

Another is to add a hack to "skip" the wrong device-node when probing
for MPICs for now and make sure it only uses the DCR node. (Note that
the last time I tested on SIMICS, I had a SLOF image that had a proper
MPIC node...)

> Also this patch doesn't allow yet the ethernet driver to work on xCAB for 
> 2.6.19.
> 
> Signed-off-by: Jean-Christophe Dubois <jdubois at mc.com>

I don't see any good reason to merge that patch though. SLOF will be
fixed soon enough and there are better workarounds anyway since you say
the tree contains the proper DCR-based MPIC node. Just skip the wrong
one for now from the platform code. I don't think that patch nor the
workaround needs to be merged in any tree anyway as the firmware will be
fixed.

Regarding EMAC, there seem to be other issues that Murali reported to
me. I need to do a new patch with the workarounds he sent me along with
other cleanups. Hopefully, next week.

Cheers,
Ben.