From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 9ED2AB725F for ; Sat, 19 Nov 2011 01:35:12 +1100 (EST) Subject: Re: [PATCH v2 1/7] powerpc/85xx: re-enable timebase sync disabled by KEXEC patch Mime-Version: 1.0 (Apple Message framework v1251.1) Content-Type: text/plain; charset=us-ascii From: Kumar Gala In-Reply-To: <4EC40406.1030408@freescale.com> Date: Fri, 18 Nov 2011 08:35:02 -0600 Message-Id: <54122A43-37D1-438B-A0DD-289B7AE2BA0B@kernel.crashing.org> References: <1321437344-19253-1-git-send-email-chenhui.zhao@freescale.com> <4EC40406.1030408@freescale.com> To: Scott Wood Cc: linuxppc-dev@lists.ozlabs.org, Zhao Chenhui List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Nov 16, 2011, at 12:42 PM, Scott Wood wrote: > On 11/16/2011 03:55 AM, Zhao Chenhui wrote: >> From: Li Yang >>=20 >> The timebase sync is not only necessary when using KEXEC. It should = also >> be used by normal boot up and cpu hotplug. Remove the ifdef added by >> the KEXEC patch. >=20 > Again, no it should not be used by normal boot up (whether KEXEC = support > is enabled or not). We should only do timebase sync when we actually > need to (when we've actually just reset a core), and we should do it = the > way U-Boot does rather than with smp-tbsync.c. How can we do u-boot bases timebase sync after the system us up and = running? For example would we losing some ticks of time in the case = that one core is up and we bring a second core online? - k=