2.6.x on 405CR

[Piotr Perak]

On Tue, 28 Sep 2004, Matt Porter wrote:

> On Tue, Sep 28, 2004 at 11:57:44AM +0200, Piotr Perak wrote:
> > Because I use ibm405cr.c which works good with 2.4.23 I think that's not
> > the problem. Remember the call stack?
> 
> Which 2.4 tree?  linux-2.4, linuxppc-2.4, and linuxppc_2_4_devel haven't
> had explicit 405cr support that I've noticed. Since the ocp layer has
> changed that would leave open the possibility of a problem in translating
> the support to the new ocp layer.

linux-2.4 ported to our board some time ago.  

> 
> > setup_arch() - arch/ppc/kernel/setup.c
> >   -> ocp_early_init() - arch/ppc/syslib/ocp.c
> >     -> ocp_add_one_device() - arch/ppc/syslib/ocp.c
> >       ->  alloc_bootmem MACRO calling __alloc_bootmem_core() -
> > mm/bootmem.c
> > 
> > When I comment line calling ocp_early_init() I fail in:
> >  
> > setup_arch() - arch/ppc/kernel/setup.c
> >   -> paging_init() - arch/ppc/mm/init.c
> >     -> free_area_init() - arch/ppc/mm/page_alloc.c
> >       -> free_area_init_node() - arch/ppc/mm/page_alloc.c
> >         -> alloc_bootmem_node() MACRO calling __alloc_bootmem_node -
> > mm/bootmem.c
> >           -> __alloc_bootmem_core() - mm/bootmem.c
> > 
> > As you can see again __alloc_bootmem_core. So maybe there's some
> > problem with memory?
> 
> Hrm, I see. Did your firmware change between your working 2.4 kernel
> and your non-working 2.6 kernel?  If you're failing in there that would
> be my first thought. I suppose that's probably not that case though.

2.4.23 still runs on board I try to port 2.6.8.1 to. So I guess firmware
is not the problem?

> Well, the 405cr support issue is really throwing me for a loop here. If
> you're crashing in _alloc_bootmem_core() and haven't hacked any MM code
I haven't change any MM code.

> then you're an interesting spot.  Can you trace it down to the exact
> failure in __alloc_bootmem_core?
I already did it. Can you please read
http://ozlabs.org/pipermail/linuxppc-dev/2004-September/000104.html? I
described there what weird things are happening in __alloc_bootmem_core.

Piotr Perak