From mboxrd@z Thu Jan  1 00:00:00 1970
From: santosh.shilimkar@ti.com (Santosh Shilimkar)
Date: Fri, 22 Jul 2011 10:26:07 +0530
Subject: [PATCH] ARM: do not mark CPU 0 as hotpluggable
In-Reply-To: <20110721133033.GN26574@n2100.arm.linux.org.uk>
References: <1311204745-6276-1-git-send-email-mturquette@ti.com>
	<4E2796DA.80001@gmail.com> <4E27BA10.3060203@ti.com>
	<20110721133033.GN26574@n2100.arm.linux.org.uk>
Message-ID: <4E2902E7.6000108@ti.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

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