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

[Kumar Gala]

On May 17, 2011, at 4:40 PM, 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'm trying to work on it ;)

- k