Subject: Re: [PATCH ppc-next] powerpc/fsl-booke: don't load early TLB at once

From: Scott Wood <[email-masked]>
Date: Thu, 20 Sep 2018 19:31:33 -0500

On Fri, 2018-09-21 at 00:48 +0200, David Lamparter wrote:
> This is a *partial* revert of "powerpc/85xx: Load all early TLB entries
> at once" (d9e1831a420267a7ced708bb259d65b0a3c0344d.)
> 
> My dusty old P4080DS just completely fails to boot (no output at all)
> without this revert.  I have no clue what's going on here, I just
> bisected it down and since it looks like an optimization to me I just
> reverted it - and voilá, the P4080 boots again.

It's not an optimization; it was required to get kdump working, at least
for certain choices of crash kernel location.  I just tried booting a 32-
bit kernel and did not see this problem -- but I don't have access to a
p4080ds anymore.  I tried with qemu e500mc, and also running a 32-bit
kernel on e6500 (needs a tiny change to get past SMP init, since 32-bit
isn't really supported on e6500, but you do get output even without that).

Do you have a JTAG that can be used to find out where it's hanging?  If
not, I can try to get early debug working (needs an early IOMMU mapping).

York, can you try booting the latest kernel on p4080ds?

-Scott