[PASEMI NEMO] Boot issue with the PowerPC updates 6.4-1

[Rob Herring]

On Thu, May 4, 2023 at 11:52 PM Christian Zigotzky
<chzigotzky at xenosoft.de> wrote:
>
> On 03 May 2023 at 08:15 pm, Rob Herring wrote:
> > On Wed, May 3, 2023 at 12:40 PM Christian Zigotzky
> > <chzigotzky at xenosoft.de> wrote:
> >>
> >>
> >>> On 3. May 2023, at 18:51, Rob Herring <robh at kernel.org> wrote:
> >>>
> >>> On Wed, May 3, 2023 at 11:27 AM Christophe Leroy
> >>> <christophe.leroy at csgroup.eu> wrote:
> >>>> +Rob as he's the commit's Author.
> >>>>
> >>>>> Le 03/05/2023 à 17:46, Christian Zigotzky a écrit :
> >>>>> On 02 May 2023 at 11:28 am, Michael Ellerman wrote:
> >>>>>> Christian Zigotzky <chzigotzky at xenosoft.de> writes:
> >>>>>>> Hello,
> >>>>>>>
> >>>>>>> Our PASEMI Nemo board [1] doesn't boot with the PowerPC updates 6.4-1
> >>>>>>> [2].
> >>>>>>>
> >>>>>>> The kernel hangs right after the booting Linux via __start() @
> >>>>>>> 0x0000000000000000 ...
> >>>>>>>
> >>>>>>> I was able to revert the PowerPC updates 6.4-1 [2] with the following
> >>>>>>> command: git revert 70cc1b5307e8ee3076fdf2ecbeb89eb973aa0ff7 -m 1
> >>>>>>>
> >>>>>>> After a re-compiling, the kernel boots without any problems without the
> >>>>>>> PowerPC updates 6.4-1 [2].
> >>>>>>>
> >>>>>>> Could you please explain me, what you have done in the boot area?
> >>>>>> There's a few possibilities, but nothing obvious.
> >>>>>>
> >>>>>> To begin with can you please test the following commits?
> >>>>>>
> >>>>>> 77e69ee7ce07
> >>>>>> e4ab08be5b49
> >>>>>> eeac8ede1755
> >>>>>>
> >>>>>> cheers
> >>>>> git revert e4ab08be5b4902e5b350b0e1e1a3c25eb21d76d4
> >>>>>
> >>>>> [master 0086e2cbbec0] Revert "powerpc/isa-bridge: Remove open coded
> >>>>> "ranges" parsing"
> >>>>>   1 file changed, 129 insertions(+), 37 deletions(-)
> >>>>>
> >>>>> After a recompiling it boots without any problems.
> >>>>>
> >>>>> e4ab08be5b49 -- powerpc/isa-bridge: Remove open coded "ranges" parsing
> >>>>> is the bad commit.
> >>> Could I get a DT file for this board?
> >>>
> >>> In the meantime, just revert this commit. I don't think I'll be able
> >>> to fix it before I'm out on sabbatical.
> >>>
> >>> Rob
> >> FYI:
> >>
> >> Darren Stevens wrote:
> >>
> >> The dtb passed by the CFE firmware has a number of issues, which up till
> >> now have been fixed by use of patches applied to the mainline kernel.
> >> This occasionally causes problems with changes made to mainline.
> > Changing the firmware is not the only way to modify the DT. Perhaps a
> > DT overlay would work better than carrying patches if the patches
> > aren't upstreamable. It kind of depends on how early you'd need to
> > apply the overlay and whether you'd need external phandles (aka
> > __symbols__ node, which the base DTB wouldn't support).
> >
> > Looking at the DT, I think this change might fix it. Can you test this change:
> >
> > diff --git a/drivers/of/address.c b/drivers/of/address.c
> > index e692809ff822..475b74413fdd 100644
> > --- a/drivers/of/address.c
> > +++ b/drivers/of/address.c
> > @@ -284,7 +284,7 @@ EXPORT_SYMBOL(of_range_to_resource);
> >
> >   static int of_bus_isa_match(struct device_node *np)
> >   {
> > -       return of_node_name_eq(np, "isa");
> > +       return of_node_is_type(np, "isa") || of_node_name_eq(np, "isa");
> >   }
> >
> >   static void of_bus_isa_count_cells(struct device_node *child,
> I tested this patch today but unfortunately the Nemo board doesn't boot.

Do you have a dmesg log with debug enabled for a successful boot? I
searched archives and forum, but couldn't find one. isa-bridge.c has
debug enabled so you should get a few messages.

>From looking at the DT, the isa node has no ranges, so the difference
in parsing code shouldn't even matter. You should be seeing this
message:

        printk(KERN_ERR "no ISA IO ranges or unexpected isa range, "
               "mapping 64k\n");

Rob