5.3.7 64-bits kernel doesn't boot on G5 Quad

[Romain Dolbeau]

Hello,

Following my bug report on debian-powerpc and the following, I'm
adding linuxppc-dev to my answer.

Le jeu. 7 nov. 2019 à 11:09, Mathieu Malaterre <malat at debian.org> a écrit :
> On Thu, Nov 7, 2019 at 9:34 AM John Paul Adrian Glaubitz
> > The answer here would be git bisect [1]. I would first start downloading
> > the current kernel source tarball for 5.3.7 from upstream and build the
> > kernel with "make localmodconfig" to see whether it's an upstream or Debian
> > problem.
> I suspect this is upstream and even before 5.3.7. The original report
> by Christian has been discussed on linuxpcc-dev:
> <https://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg155248.html>

Thanks to you guys I was able to cross-build a kernel (native would
have been way to slow) and try to bisect the bug.
However, I ended up in another buggy behavior that may or may not be related :-(
I tried to localize the bug(s) as best I could.

I attach to this the result of 'git bisect log' to see if someone can
figure out what's going on. Some of the commits were hand-picked to
avoid doing too many 'skip' configurations with the bug described
below.

As I marked this:

*bad*: seems to behave the same as the Debian kernel or git HEAD, that
is, crash as reported (or very similar to, at least) by Christian.

*good*: either a full boot, or occasionally the kernel dropped me into
initramfs complaining about versioning of some symbols - I figured it
went far enough so it did not have the bug. The last one in the file
is a full boot as I remember it.

*skip*: most of them involves hanging just after cpus start (i.e.
including 3 messages about kick-up for the extra cpu and one about
bringing up being done, then nothing further). Those covers a lot of
commits :-(

(I used <https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git>
and my build command was "make ARCH=powerpc
CROSS_COMPILE=powerpc64-linux-gnu- oldconfig && make ARCH=powerpc
CROSS_COMPILE=powerpc64-linux-gnu- -j56 bindeb-pkg", using default
values for oldconfig, starting with the config file from Debian at the
beginning, cross-gcc is 8.3 from buster, tested on a G5 Quad).

Any suggestion, advice, or patch to try welcome :-)

Thanks in advance& cordially,

-- 
Romain Dolbeau
-------------- next part --------------
A non-text attachment was scrubbed...
Name: ppc64_bisect.log.gz
Type: application/x-gzip
Size: 2561 bytes
Desc: not available
URL: <http://lists.ozlabs.org/pipermail/linuxppc-dev/attachments/20191110/1c8c8f6e/attachment.bin>