Rob Herring [off-list ref] writes:

On Mon, Jul 30, 2018 at 4:47 AM Michael Ellerman [off-list ref] wrote:

quoted

Rob Herring [off-list ref] writes:

quoted

On Thu, Jul 26, 2018 at 11:36 PM Michael Ellerman [off-list ref] wrote:

quoted

When the OF code was originally made common by Grant in commit
51975db0b733 ("of/flattree: merge early_init_dt_scan_memory() common
code") (Feb 2010), the common code inherited a hack to handle
PPC "longtrail" machines, which had a "memory@0" node with no
device_type.

That check was then made to only apply to PPC32 in b44aa25d20e2 ("of:
Handle memory@0 node on PPC32 only") (May 2014).

But according to Paul Mackerras the "longtrail" machines are long
dead, if they were ever seen in the wild at all. If someone does still
have one, we can handle this firmware wart in powerpc platform code.

So remove the hack once and for all.

Yay. I guess Power Macs and other quirks will never die...

Not soon.

In base.c I see:
 - the hack in arch_find_n_match_cpu_physical_id()
   - we should just move that into arch code, it's a __weak arch hook
     after all.

Except then we'd have to export __of_find_n_match_cpu_property. I
somewhat prefer it like it is because arch specific functions tend to
encourage duplication. But if the implementation is completely
different like sparc, then yes, a separate implementation makes sense.

OK I'll leave it as-is then.

quoted

 - a PPC hack in of_alias_scan(), I guess we need to retain that
   behaviour, but it's pretty minor anyway.

It would be nice to know what platform(s) needs this as I don't have a
clue.

Yeah.

It would also be nice if I had some dumps of DTs for some of
these OpenFirmware systems.

Yeah it would. What if I threw some in a git tree somewhere?

I guess fully unpacked is the most useful form, ie. just a direct copy
from /proc/device-tree.

cheers