From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH 0/6] ARM: tegra114: add CPU hotplug support Date: Wed, 15 May 2013 17:38:00 -0600 Message-ID: <51941C58.9060002@wwwdotorg.org> References: <1368613644-11863-1-git-send-email-josephl@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1368613644-11863-1-git-send-email-josephl-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Joseph Lo Cc: linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 05/15/2013 04:27 AM, Joseph Lo wrote: > Tegra 114 is different with other Tegra SoC chips. It using ARM Cortex-A15 > as CPU core and a enhanced flow controller for CPU power control. So > we need to skip some code that was for Contex-A9 and some other support > code that was for other Tegra SoC chips. Then adding the proper power up > and hot plug control for Tegra114. This series mostly works OK, but I see one problem: I can't hotunplug CPU0, which the commit descriptions and code changes imply I should be able to do: root@localhost:~# echo 0 > /sys/devices/system/cpu/cpu0/online -bash: echo: write error: Operation not permitted