On Thu, Sep 20, 2018 at 07:31:33PM -0500, Scott Wood wrote: > 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
Oh, my apologies for misunderstanding the code. > 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). Hrm, maybe I should just make it use the old mechanism under an #ifdef CONFIG_PPC32? Better to boot and have kdump not work than not boot. (But obviously finding the actual problem would be best.) > 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). I only have JTAG tools for ARM chips available; hardware wise I could probably solder up an adapter but software wise I have absoutely no clue how to fire up a session on anything PPC... I'm a novice openocd user, that's it. > York, can you try booting the latest kernel on p4080ds? d9e1831a42 has been around for quite some time, 4.4 already has it. I was a bit surprised noone has run into this, but then again P4080 is not exactly the most recent/interesting hardware. Cheers, -David
