Re: Since 6.10 - kernel oops/panics on G4 macmini due to change in drivers/ata/pata_macio.c

["Kolbjørn Barmen" <linux-ppc@kolla.no>]

On Tue, 13 Aug 2024, Michael Ellerman wrote:

> Niklas Cassel <cassel@kernel.org> writes:
> > Hello Jonáš, Kolbjørn,
> >
> > thank you for the report.
> >
> > On Tue, Aug 13, 2024 at 07:49:34AM +0200, Jonáš Vidra wrote:
> >> On Tue 13. Aug 2024 0:32:37 CEST, Kolbjørn Barmen wrote:
> >> > Ever since 6.10, my macmini G4 behaved unstable when dealing with lots of
> >> > I/O activity, such as sync'ing of Gentoo portage tree, unpacking kernel
> >> > source tarball, building large software packages (or kernel) etc.
> >> > 
> >> > After a bit of testing, and patient kernel rebuilding (while crashing) I
> >> > found the cuplit to be this commit/change
> >> > 
> >> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/diff/?id=09fe2bfa6b83f865126ce3964744863f69a4a030
> >> 
> >> I've been able to reproduce this pata_macio bug on a desktop PowerMac G4
> >> with the 6.10.3 kernel version. Reverting the linked change
> >> ("ata: pata_macio: Fix max_segment_size with PAGE_SIZE == 64K") makes
> >> the errors go away.
> >
> > Michael, as the author of the this commit, could you please look into
> > this issue?
> 
> I can. My commit was really just working around the warning in the SCSI
> core which appeared after afd53a3d8528, it was supposed to just fix the
> warning without changing behaviour. Though obviously it did for 4KB
> PAGE_SIZE kernels.
> 
> I don't have easy access to my mac-mini so it would be helpful if you
> can test changes Jonáš and/or Kolbjørn.

I applied your patch (to 6.10.4 sources) and built a kernel, and did some stress
testing (tarring adnd untarring large archives) and so far it looks good.


Thanks! :)


-- kolla