v4.17 regression: PowerMac G3 won't boot, was Re: [PATCH v5 1/3] of: cache phandle nodes to reduce cost of of_find_node_by_phandle()

[Benjamin Herrenschmidt]

On Thu, 2018-08-30 at 21:36 -0700, Frank Rowand wrote:
> > No idea whether that's relevant; I haven't done any further investigation. 
> > Complete dmesg output is attached. Please let me know if there's any more 
> > information you need to help find the bug.
> > 
> > Thanks.
> 
> I don't have any useful answers yet, but I am following the thread and have
> also quickly scanned the two commits for any obvious cause.  I will look
> into this some more, but have a few other tasks that I need to complete
> first.
> 
> A long shot, but something to consider, is that I failed to cover the
> cases of dynamic devicetree updates (removing nodes that contain a
> phandle) in ways other than overlays.  Michael Ellerman has reported
> such a problem for powerpc/mobility with of_detach_node().  A patch to
> fix that is one of the tasks I need to complete.

The only thing I can think of is booting via the BootX bootloader on
those ancient macs results in a DT with no phandles. I didn't see an
obvious reason why that would cause that patch to break though.

Cheers,
Ben.