2.6.34 hangs during boot on PB11MPCore

[Bjoern Brandenburg]

On Sun, May 30, 2010 at 9:04 PM, Bjoern Brandenburg <bbb.lst at gmail.com> wrote:
> On Sun, May 30, 2010 at 6:46 PM, Catalin Marinas
> <catalin.marinas at arm.com> wrote:
>> On Sun, 2010-05-30 at 22:38 +0100, Bjoern Brandenburg wrote:
>>> On Sun, May 30, 2010 at 5:05 PM, Bjoern Brandenburg <bbb.lst at gmail.com> wrote:
>>> > On Sun, May 30, 2010 at 3:27 PM, Bjoern Brandenburg <bbb.lst at gmail.com> wrote:
>>> >>
>>> >> I'll try to see if I can pinpoint what was dropped between 2.6.33-arm1
>>> >> and 2.6.34-arm.
>>> >
>>> > Progress: I can get 2.6.34-arm to boot with all 4 CPUs after
>>> > cherry-picking the following commits (which seemed relevant but
>>> > absent):
>>> >
>>> > 60060ca ARM: Handle instruction cache maintenance fault  properly
>>> > 3f64e83 ARM errata: Eviction Buffer not empty after Cache Sync on L220
>>> > 3b009b5 ARM: change definition of cpu_relax() for ARM11MPCore
>>> >
>>> > Let's see which is the critical one...
>>>
>>> It's 3f64e83 "ARM errata: Eviction Buffer not empty after Cache Sync
>>> on L220" [1]. With this commit cherry-picked (on top of the 'rebased'
>>> branch in ARM's repository, i.e., 2.6.34-arm), the system boots to X11
>>> and runs some simple FS tests; the other ones don't make a difference.
>>>
>>> Are there plans for getting this and the other patches in the
>>> 'rebased' branch into mainline (for .35 or .36)?
>>
>> Thanks for the investigation. I recall I got something similar in the
>> past though I could no longer reproduce it with 2.6.34 (-arm) on the
>> PB11MPCore I have. Could you try reverting commit e7c5650f606 (ARM:
>> Change the mandatory barriers implementation) on a vanilla 2.6.34
>> kernel?
>
> That doesn't seem to help. v2.6.34 with e7c5650f606 reverted still hangs.

Given that 2.6.34-arm contains patches for missing synchronization
primitives in the network driver, it is maybe not too surprising that
the vanilla kernel won't boot with an NFS root file system.

I just tried 2.6.34-arm (i.e., the 'rebased' branch in the ARM repo)
with e7c5650f606 reverted (and without cherry-picking 3f64e83)   and
that kernel boots ok!

- Björn