From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [103.22.144.67]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 506861A05E1 for ; Tue, 23 Dec 2014 12:00:42 +1100 (AEDT) Message-ID: <1419296441.30550.3.camel@ellerman.id.au> Subject: Re: [PATCH] powerpc/smp: Fix Non-boot cpus cannot be bring up. From: Michael Ellerman To: Dongsheng Wang Date: Tue, 23 Dec 2014 12:00:41 +1100 In-Reply-To: <1419230320-37558-1-git-send-email-dongsheng.wang@freescale.com> References: <1419230320-37558-1-git-send-email-dongsheng.wang@freescale.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: scottwood@freescale.com, linuxppc-dev@lists.ozlabs.org, anton@samba.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 2014-12-22 at 14:38 +0800, Dongsheng Wang wrote: > From: Wang Dongsheng > > Kernel cannot bring up Non-boot cpus always get "Processor xx is stuck". > this issue bring by http://patchwork.ozlabs.org/patch/418912/ (powerpc: > Secondary CPUs must set cpu_callin_map after setting active and online) > We need to take timebase after bootup cpu give the timebase firstly. > > When start_secondary, non-boot cpus set cpu_callin_map for boot cpu > after that boot cpu will give the timebase for non-boot cpu. Otherwise > non-boot cpus will fall in dead loop to waiting bootup cpu to give > imebase. Right. However, doesn't this introduce the possibility that the secondary cpu is up and marked online but has an unsynchronised clock? cheers