On Nov 4, 2011, at 12:33 PM, Scott Wood wrote:
> On 11/04/2011 07:29 AM, Zhao Chenhui wrote:
>> From: Li Yang <le...@freescale.com>
>>
>> The timebase sync is not only necessary when using KEXEC. It should also
>> be used by normal boot up and cpu hotplug. Remove the ifdef added by
>> the KEXEC patch.
>
> The KEXEC patch didn't just add the ifdef, it also added the initializers:
>
>> @@ -105,8 +107,64 @@ smp_85xx_setup_cpu(int cpu_nr)
>>
>> struct smp_ops_t smp_85xx_ops = {
>> .kick_cpu = smp_85xx_kick_cpu,
>> +#ifdef CONFIG_KEXEC
>> + .give_timebase = smp_generic_give_timebase,
>> + .take_timebase = smp_generic_take_timebase,
>> +#endif
>> };
>
> U-Boot synchronizes the timebase on 85xx. With what chip and U-Boot
> version are you seeing this not happen?
>
> If you are seeing only a small (around one tick) difference, make sure
> you're running a U-Boot that has this commit:
>
>> commit 7afc45ad7d9493208d89072cbb78a5bfc8034b59
>> Author: Kumar Gala <ga...@kernel.crashing.org>
>> Date: Sun Mar 13 10:55:53 2011 -0500
>>
>> powerpc/85xx: Fix synchronization of timebase on MP boot
>>
>> There is a small ordering issue in the master core in that we need to
>> make sure the disabling of the timebase in the SoC is visible before we
>> set the value to 0. We can simply just read back the value to
>> synchronizatize the write, before we set TB to 0.
>>
>> Reported-by: Dan Hettena
>> Tested-by: Dan Hettena
>> Signed-off-by: Kumar Gala <ga...@kernel.crashing.org>
Scott,
Aren't we going to need this when a core is woken back up w/o any state?
- k
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