From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753847Ab3KGVWt (ORCPT ); Thu, 7 Nov 2013 16:22:49 -0500 Received: from mail-ee0-f45.google.com ([74.125.83.45]:48384 "EHLO mail-ee0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752009Ab3KGVWl (ORCPT ); Thu, 7 Nov 2013 16:22:41 -0500 Message-ID: <527C049B.4030608@gmail.com> Date: Thu, 07 Nov 2013 22:22:35 +0100 From: Sebastian Hesselbarth User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.1.0 To: Arnd Bergmann CC: Jisheng Zhang , Russell King , Kevin Hilman , "linux-kernel@vger.kernel.org" , Olof Johansson , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH v3 9/9] ARM: add initial support for Marvell Berlin SoCs References: <1381235073-17134-1-git-send-email-sebastian.hesselbarth@gmail.com> <20131107134033.59bd127a@xhacker> <527B67A1.3020803@gmail.com> <201311071720.47489.arnd@arndb.de> In-Reply-To: <201311071720.47489.arnd@arndb.de> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/07/2013 05:20 PM, Arnd Bergmann wrote: > On Thursday 07 November 2013, Sebastian Hesselbarth wrote: >> Actually, IIRC smp_twd does not compile without SMP set, so the above >> should at least be 'HAVE_ARM_TWD if SMP'. If you shrink MULTI_V7 down >> to non-SMP cores, you can disable it and it will fail to compile. > > If there are UP-systems for which TWD is the best clocksource, we should > probably fix the code to allow that configuration. IIRC there were already > patches recently in this area, maybe it's already solved. I just tried barebox bootloader to use TWD as timer on berlin2cd and it perfectly works, i.e. with time related commands I can see the timer register decreasing. So the timer is available on this UP SoC. As said before, compiling linux without CONFIG_SMP but with CONFIG_HAVE_ARM_TWD gives: warning: (SOC_OMAP5 && ARCH_ROCKCHIP && ARCH_SHMOBILE_MULTI && MACH_BERLIN_BG2 && MACH_BERLIN_BG2CD) selects HAVE_ARM_TWD which has unmet direct dependencies (SMP) and arch/arm/kernel/smp_twd.c: In function 'twd_local_timer_of_register': arch/arm/kernel/smp_twd.c:391: error: 'setup_max_cpus' undeclared (first use in this function) arch/arm/kernel/smp_twd.c:391: error: (Each undeclared identifier is reported only once arch/arm/kernel/smp_twd.c:391: error: for each function it appears in.) make[1]: *** [arch/arm/kernel/smp_twd.o] Error 1 I haven't looked deeper into this, but I guess it will not be hard to make ARM_TWD independent of SMP. Sebastian