From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 047E7C43387 for ; Wed, 19 Dec 2018 11:28:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C559C20815 for ; Wed, 19 Dec 2018 11:28:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="Z2NPpYsq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729349AbeLSL2n (ORCPT ); Wed, 19 Dec 2018 06:28:43 -0500 Received: from pandora.armlinux.org.uk ([78.32.30.218]:57076 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727052AbeLSL2n (ORCPT ); Wed, 19 Dec 2018 06:28:43 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2014; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=WqHUVLUfIoE00Ln53uW+O7Jj8T8VKU0wtQkLhv5WPMs=; b=Z2NPpYsqjBmr9qqBSQc6qszMl wKBrTrMe+LF+GrVwR3prkvlFlc1UCVsmQbYLxUxyqJh3TKmMVQAf8dqQu5d+AXsKJc1iukkf/Wm4S NJnKkeoYFrMb+asqWT/jr3n1fKBnJuPNDAltiUBJQZATWLixHY2nr8DQI8lwwF03xnWig=; Received: from n2100.armlinux.org.uk ([2001:4d48:ad52:3201:214:fdff:fe10:4f86]:44631) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.90_1) (envelope-from ) id 1gZa1l-0003Cv-6N; Wed, 19 Dec 2018 11:28:37 +0000 Received: from linux by n2100.armlinux.org.uk with local (Exim 4.90_1) (envelope-from ) id 1gZa1i-0004GA-Fj; Wed, 19 Dec 2018 11:28:34 +0000 Date: Wed, 19 Dec 2018 11:28:32 +0000 From: Russell King - ARM Linux To: Patrice CHOTARD Cc: "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 1/1] ARM: STi: Restore secondary CPU's bringup Message-ID: <20181219112832.GT26090@n2100.armlinux.org.uk> References: <1545144493-11600-1-git-send-email-patrice.chotard@st.com> <20181218155239.GP26090@n2100.armlinux.org.uk> <20181218172748.GQ26090@n2100.armlinux.org.uk> <913263b2-7421-5174-2e7d-5a15df40e51e@st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <913263b2-7421-5174-2e7d-5a15df40e51e@st.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Dec 19, 2018 at 10:31:35AM +0000, Patrice CHOTARD wrote: > Hi Russell > > On 12/18/18 6:27 PM, Russell King - ARM Linux wrote: > > On Tue, Dec 18, 2018 at 05:05:18PM +0000, Patrice CHOTARD wrote: > >> Hi Russell > >> > >> On 12/18/18 4:52 PM, Russell King - ARM Linux wrote: > >>> On Tue, Dec 18, 2018 at 03:48:13PM +0100, patrice.chotard@st.com wrote: > >>>> From: Patrice Chotard > >>>> > >>>> Due to pen_release and boot_lock removal, secondary CPU's bringup > >>>> was broken. Restore CPU's bringup by reworking properly > >>>> .smp_prepare_cpus and .smp_boot_secondary STi callbacks. > >>> > >>> Sorry, maybe I don't understand your commit message, but you seem to be > >>> saying that removal of the pen_release and boot_lock broke STi's secondary > >>> CPU bring up? Please clarify, and explain how that happened. > >> > >> Correct, CPU1 failed to come online. > >> > >> It seems that writing secondary_startup address at cpu-release-addr in > >> .smp_prepare_cpus callback was too early. > >> > >> Doing it in .smp_boot_secondary callback, insures that secondary_data > >> struct is populated in __cpu_up() (stack, pgdir and swapper_pg_dir fields). > > > > Ah, you're saying that it causes the CPU to jump to secondary_startup > > while the boot CPU is in smp_prepare_cpus()? What triggers the CPU > > Yes > > > to jump to the address written to cpu_strt_ptr? What you're saying > > seems to suggest that it's the write to that address, rather than the > > IPI that's sent in sti_boot_secondary(). > > At platform startup, an U-Bootrom firmware initialize secondary CPU and > make it spinning waiting for a jump address to be written at cpu_strt_ptr. > > I didn't pay attention to the IPI, you are right IPI is useless, i will > remove it. Okay, in that case may I suggest an alternative to taking my patch which will break this, and then fixing it in a subsequent patch - please merge the two patches together so it becomes one "clean up" patch which doesn't cause any breakage. Thanks. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up