am335x: 5.18.x: system stalling

[Ard Biesheuvel]

On Fri, 3 Jun 2022 at 22:47, Arnd Bergmann <arnd at arndb.de> wrote:
>
> On Fri, Jun 3, 2022 at 9:11 PM Yegor Yefremov
> <yegorslists at googlemail.com> wrote:
> >
> > With compiled-in drivers the system doesn't stall. All other tests and
> > related outputs will come next week.
>
> Ah, nice!
>
> It's probably a reasonable assumption that the smp-patched get_current()
> is (at least sometimes) broken in modules but working in the kernel itself.
> I suppose that means in the worst case we can hot-fix the issue by
> having an 'extern' version of get_current() for the case of
> armv6+smp+module ;-)
>

I've coded something up along those lines, and pushed it to my
am335x-stall-test branch.

> Maybe start with the ".long 0xe7f001f2" hack I suggested in my last
> mail. If that gives you an oops for the module case, then we know
> that the patching doesn't work at all and you don't have to try anything
> else, otherwise it's more likely that an incorrect instruction sequence
> is patched in.
>

Yeah, I'd be really surprised if the patching misses some occurrences,
so I have no clue what is going on here.

Yegor, can you please try my branch with the original config (i.e.,
slcan and ftdio as modules)

https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/log/?h=am335x-stall-test