unrecoverable exception on G5 with CONFIG_PPC_EARLY_DEBUG enabled

[Michael Ellerman]

On Mon, 2016-06-06 at 10:52 +0300, Denis Kirjanov wrote:

> Update: now with the proper mailing address.
> 
> Hi,
> 
> Posting if anyone knows how to quickly fix it :)

Sorry but no.

> Enabling  CONFIG_PPC_EARLY_DEBUG on my quad G5 causes kernel to die
> with the  unrecoverable exception 4100.

That means you took a SLB miss when MSR_RI was off.

What's at c000000000ace328 ?

> I haven't bisected this yet. Photo attached.

A bisect would be awesome.

cheers