From mboxrd@z Thu Jan  1 00:00:00 1970
From: tony@atomide.com (Tony Lindgren)
Date: Tue, 28 Mar 2017 13:12:15 -0700
Subject: [PATCHv3] ARM: omap2+: Revert omap-smp.c changes resetting CPU1
 during boot
In-Reply-To: <20170328191524.GM23750@n2100.armlinux.org.uk>
References: <20170314180555.23597-1-tony@atomide.com>
 <aa5d7ee3-2e54-2c6c-df5d-b5efff4b365e@ti.com>
 <20170327164308.GK10760@atomide.com>
 <20170328113657.GL23750@n2100.armlinux.org.uk>
 <20170328170944.GY10760@atomide.com>
 <20170328191524.GM23750@n2100.armlinux.org.uk>
Message-ID: <20170328201215.GB10760@atomide.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

* Russell King - ARM Linux <linux@armlinux.org.uk> [170328 12:17]:
> On Tue, Mar 28, 2017 at 10:09:44AM -0700, Tony Lindgren wrote:
> > OK so how about the following to disable kexec for Andrew's
> > test case?
> 
> That won't work - the hook you're using is to decide whether a particular
> CPU (normally the boot CPU) can be hot-plugged.  It isn't expected to
> return false for all.
> 
> The code in question is:
> 
>         /*
>          * Validate that if the current HW supports SMP, then the SW supports
>          * and implements CPU hotplug for the current HW. If not, we won't be
>          * able to kexec reliably, so fail the prepare operation.
>          */
>         if (num_possible_cpus() > 1 && platform_can_secondary_boot() &&
>             !platform_can_cpu_hotplug())
>                 return -EINVAL;
> 
> and:
> 
> int platform_can_cpu_hotplug(void)
> {
> #ifdef CONFIG_HOTPLUG_CPU
>         if (smp_ops.cpu_kill)
>                 return 1;
> #endif
> 
>         return 0;
> }
> 
> Platforms don't get a say in that, other than whether they implement
> the operations necessary for hotplug.

Yeah OK so a separate dra7_hs_smp_ops with no cpu_kill initialized
should do the trick, right?

Regards,

Tony