From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCHv3] ARM: omap2+: Revert omap-smp.c changes resetting CPU1 during boot Date: Tue, 28 Mar 2017 20:15:24 +0100 Message-ID: <20170328191524.GM23750@n2100.armlinux.org.uk> References: <20170314180555.23597-1-tony@atomide.com> <20170327164308.GK10760@atomide.com> <20170328113657.GL23750@n2100.armlinux.org.uk> <20170328170944.GY10760@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20170328170944.GY10760@atomide.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Tony Lindgren Cc: Keerthy , "Andrew F. Davis" , Tero Kristo , Santosh Shilimkar , linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org List-Id: linux-omap@vger.kernel.org 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. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net.