Re: [PATCH] powerpc/64s: power4 nap fixup in C

Excerpts from Andreas Schwab's message of March 30, 2021 2:23 am:

On Mär 29 2021, Andreas Schwab wrote:

quoted

On Mär 29 2021, Michael Ellerman wrote:

quoted

Nicholas Piggin [off-list ref] writes:

quoted

There is no need for this to be in asm, use the new intrrupt entry wrapper.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
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Hopefully this works on a real G5 now, but I couldn't reproduce the
problem with QEMU.

It still prevents my G5 from booting.

I see differing failures.  What's common is that there is a pause of
about 60 seconds before the crash occurs.  It looks like the crash
occurs in power4_idle_nap+0x30/0x34.  Unfortuately, the BootX console is
too small to see enough.

I was now able to see the messages on the VGA console, and the problem
is actually that the cpus are starting to stall.

This is strange, I haven't been able to figure out what is wrong.

I've been looking at QEMU code and now I'll have to try find a POWER4/5
or PPC970 manual to see what exactly this MSR[POW] thing does and make 
sure QEMU matches it.

Progress might be slow. Worst case I guess we revert if it can't
be fixed before next merge window.

Thanks,
Nick