powerpc: mpc85xx regression since 2.6.39-rc2, one cpu core lame

[Richard Cochran]

On Wed, May 18, 2011 at 07:40:16AM +1000, Benjamin Herrenschmidt wrote:
> On Tue, 2011-05-17 at 18:28 +0200, Richard Cochran wrote:
> > Ben,
> > 
> > Recent 2.6.39-rc kernels behave strangely on the Freescale dual core
> > mpc8572 and p2020. There is a long pause (like 2 seconds) in the boot
> > sequence after "mpic: requesting IPIs..."
> > 
> > When the system comes up, only one core shows in /proc/cpuinfo. Later
> > on, lots of messages appear like the following:
> > 
> >    INFO: task ksoftirqd/1:9 blocked for more than 120 seconds.
> > 
> > I bisected [1] the problem to:
> > 
> >    commit c56e58537d504706954a06570b4034c04e5b7500
> >    Author: Benjamin Herrenschmidt <benh at kernel.crashing.org>
> >    Date:   Tue Mar 8 14:40:04 2011 +1100
> > 
> >        powerpc/smp: Create idle threads on demand and properly reset them
> > 
> > I don't see from that commit what had gone wrong. Perhaps you can
> > help resolve this?
> 
> Hrm, odd. Kumar, care to have a look ? That's what happens when you
> don't get me HW to test with :-)

(I get the feeling that I am the only one testing recent kernels with
the mpc85xx.)

Anyhow, I see that this commit was one of a series. For my own use,
can I simply revert this one commit independently?

Thanks,
Richard