[PATCH] ARM: do not mark CPU 0 as hotpluggable

Santosh Shilimkar santosh.shilimkar at ti.com
Fri Jul 22 00:56:07 EDT 2011


On 7/21/2011 7:00 PM, Russell King - ARM Linux wrote:
> On Thu, Jul 21, 2011 at 11:03:04AM +0530, Santosh Shilimkar wrote:
>> Just talking on behalf of OMAP, we can't offline CPU0 and limitation
>> would remain in future OMAPs too.
>
> Apart from the broken IRQ migration, and the way CPU0 immediately
> reawakes if it is offlined on OMAP4 (even when IRQs are migrated off
> CPU0) because omap_read_auxcoreboot0() returns 0, is there any other
> reason?
>
> With fixed IRQ migration and forcing CPU0 into an infinite WFI loop,
> I can offline CPU0 and still have a running system.
>
The secure software runs only on CPU0 and that's the biggest limitation.
Other issues like hand-shake as you pointed out, power sequencing etc
can be worked around.

Regards
Santosh




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