Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752828AbbBMLWM (ORCPT ); Fri, 13 Feb 2015 06:22:12 -0500 Received: from service87.mimecast.com ([91.220.42.44]:38118 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752563AbbBMLWJ convert rfc822-to-8bit (ORCPT ); Fri, 13 Feb 2015 06:22:09 -0500 Date: Fri, 13 Feb 2015 11:22:05 +0000 From: Liviu Dudau To: Russell King - ARM Linux Cc: Arnd Bergmann , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "arm@kernel.org" , Nicolas Pitre , Kevin Hilman , Sudeep Holla , Lorenzo Pieralisi Subject: Re: [PATCH 01/11] ARM: vexpress: use ARM_CPU_SUSPEND if needed Message-ID: <20150213112205.GT14954@e106497-lin.cambridge.arm.com> References: <1423770163-583064-1-git-send-email-arnd@arndb.de> <1423770163-583064-2-git-send-email-arnd@arndb.de> <20150213103716.GQ14954@e106497-lin.cambridge.arm.com> <20150213105752.GU8656@n2100.arm.linux.org.uk> <20150213110152.GR14954@e106497-lin.cambridge.arm.com> <20150213111612.GV8656@n2100.arm.linux.org.uk> MIME-Version: 1.0 In-Reply-To: <20150213111612.GV8656@n2100.arm.linux.org.uk> User-Agent: Mutt/1.5.22 (2013-10-16) X-OriginalArrivalTime: 13 Feb 2015 11:22:06.0013 (UTC) FILETIME=[4C4ABED0:01D0477F] X-MC-Unique: 115021311220715601 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3125 Lines: 82 On Fri, Feb 13, 2015 at 11:16:12AM +0000, Russell King - ARM Linux wrote: > On Fri, Feb 13, 2015 at 11:01:52AM +0000, Liviu Dudau wrote: > > On Fri, Feb 13, 2015 at 10:57:53AM +0000, Russell King - ARM Linux wrote: > > > On Fri, Feb 13, 2015 at 10:37:16AM +0000, Liviu Dudau wrote: > > > > On Thu, Feb 12, 2015 at 07:42:33PM +0000, Arnd Bergmann wrote: > > > > > The vexpress tc2 power management code calls mcpm_loopback, which > > > > > is only available if ARM_CPU_SUSPEND is enabled, otherwise we > > > > > get a link error: > > > > > > > > > > arch/arm/mach-vexpress/built-in.o: In function `tc2_pm_init': > > > > > arch/arm/mach-vexpress/tc2_pm.c:389: undefined reference to `mcpm_loopback' > > > > > > > > Arnd, > > > > > > > > We are having reports of TC2 not booting with MCPM enabled. Lorenzo > > > > was investigating this but then headed for Linaro Connect this week, > > > > so we don't have yet a resolution. Can this patch be postponed for > > > > a later -rc? > > > > > > Why? > > > > > > This patch isn't forcing MCPM to be enabled for Versatile Express. > > > > > > * In order to build tc2_pm.c, MCPM must already be enabled (the > > > feature depends on MCPM in the Kconfig already) > > > * When this feature is enabled, the above link error occurs if > > > ARM_CPU_SUSPEND is not also enabled. > > > > > > So, it is merely fixing the requirement that tc2_pm.c needs the CPU > > > suspend infrastructure, which in turn has no effect on whether MCPM > > > is enabled or not. > > > > Because I think Lorenzo's plan was to disable MCPM for TC2. Which would > > make this patch moot. > > I don't think that makes a difference - the two issues are orthogonal. > > As the code stands today, it requires ARM_CPU_SUSPEND to be set, so > merging this change makes total sense. > > If the code is temporarily disabled, then we still need this patch > merged to fix the error when the feature is re-enabled. If the code > is changed later such that it doesn't need mcpm_loopback, then that's > the time to remove the select of this symbol. > > If the code is removed, that is something which is not going to happen > during this merge window, so the patch still might as well be applied > to prevent build errors. Russell, I'm not arguing either way, I was just asking for a delay until Lorenzo (one other maintainer of the code that is in the Cc) has a chance to have his say, because I thought it was relevant (and I have explained why). If Arnd feels he would rather push the patch now rather than (let say) late Monday, then I can give my Acked-by. Best regards, Liviu > > -- > FTTC broadband for 0.8mile line: currently at 10.5Mbps down 400kbps up > according to speedtest.net. > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯ -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/