From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754026AbaI2LwR (ORCPT ); Mon, 29 Sep 2014 07:52:17 -0400 Received: from mail-bn1bon0130.outbound.protection.outlook.com ([157.56.111.130]:21604 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751913AbaI2LwP (ORCPT ); Mon, 29 Sep 2014 07:52:15 -0400 Date: Mon, 29 Sep 2014 19:51:41 +0800 From: Shawn Guo To: Stefan Agner CC: , , , , , , , Subject: Re: [PATCH v2 3/3] ARM: vf610: Add ARM Global Timer clocksource option Message-ID: <20140929115122.GA14087@tiger> References: <1411575610-20895-1-git-send-email-stefan@agner.ch> <1411575610-20895-4-git-send-email-stefan@agner.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1411575610-20895-4-git-send-email-stefan@agner.ch> User-Agent: Mutt/1.5.21 (2010-09-15) X-Originating-IP: [221.225.208.47] X-ClientProxiedBy: SINPR01CA010.apcprd01.prod.exchangelabs.com (10.242.48.20) To BY2PR03MB345.namprd03.prod.outlook.com (10.141.139.11) X-Microsoft-Antispam: UriScan:; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;SRVR:BY2PR03MB345; X-Forefront-PRVS: 034902F5BC X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(6009001)(199003)(24454002)(51704005)(189002)(120916001)(4396001)(42186005)(47776003)(83072002)(92566001)(92726001)(83322001)(19580395003)(99396003)(110136001)(85852003)(87976001)(85306004)(19580405001)(83506001)(107046002)(64706001)(20776003)(23726002)(33656002)(86362001)(575784001)(90102001)(101416001)(66066001)(21056001)(33716001)(97736003)(95666004)(76482002)(46406003)(97756001)(106356001)(77096002)(10300001)(50986999)(54356999)(76176999)(50466002)(80022003)(74662003)(79102003)(105586002)(74502003)(77982003)(46102003)(31966008)(81542003)(81342003);DIR:OUT;SFP:1102;SCL:1;SRVR:BY2PR03MB345;H:tiger;FPR:;MLV:sfv;PTR:InfoNoRecords;A:1;MX:1;LANG:en; X-OriginatorOrg: freescale.com Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Sep 24, 2014 at 06:20:10PM +0200, Stefan Agner wrote: > Add the ARM Global Timer as clocksource/scheduler clock option and > use it as default scheduler clock. This leaves the PIT timer for > other users e.g. the secondary Cortex-M4 core. Also, the Global Timer > has double the precission (running at pheripheral clock compared to > IPG clock) and a 64-bit incrementing counter register. We still keep > the PIT timer as an secondary option in case the ARM Global Timer is > not available. > > Signed-off-by: Stefan Agner > --- > arch/arm/mach-imx/Kconfig | 19 ++++++++++++++++++- > 1 file changed, 18 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig > index 11b2957..9482f58 100644 > --- a/arch/arm/mach-imx/Kconfig > +++ b/arch/arm/mach-imx/Kconfig > @@ -633,12 +633,29 @@ config SOC_VF610 > bool "Vybrid Family VF610 support" > select ARM_GIC > select PINCTRL_VF610 > - select VF_PIT_TIMER > select PL310_ERRATA_769419 if CACHE_L2X0 > > help > This enable support for Freescale Vybrid VF610 processor. > > +choice > + prompt "Clocksource for scheduler clock" > + depends on SOC_VF610 > + default ARM_GLOBAL_TIMER > + > + config ARM_GLOBAL_TIMER > + bool "Use ARM Global Timer" > + select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK > + help > + Use the ARM Global Timer as clocksource > + > + config VF_PIT_TIMER > + bool "Use PIT timer" > + help > + Use SoC Periodic Interrupt Timer (PIT) as clocksource > + > +endchoice > + As per the report from 0-DAY kernel build test (thanks), the change causes the following warning on a particular config. warning: (ARCH_ROCKCHIP && ARCH_BCM_5301X) selects CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK which has unmet direct dependencies (ARM_GLOBAL_TIMER) It looks the redefinition of ARM_GLOBAL_TIMER is the cause for that warning. I think it's more safer to use new config symbols for choosing the clocksource device for VF610. I propose the following change to fix the warning. If there is no objection, I will squash it into the original commit soon. diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig index 9482f5837b7e..e26b0fdd72db 100644 --- a/arch/arm/mach-imx/Kconfig +++ b/arch/arm/mach-imx/Kconfig @@ -641,16 +641,18 @@ config SOC_VF610 choice prompt "Clocksource for scheduler clock" depends on SOC_VF610 - default ARM_GLOBAL_TIMER + default VF_USE_ARM_GLOBAL_TIMER - config ARM_GLOBAL_TIMER + config VF_USE_ARM_GLOBAL_TIMER bool "Use ARM Global Timer" + select ARM_GLOBAL_TIMER select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK help Use the ARM Global Timer as clocksource - config VF_PIT_TIMER + config VF_USE_PIT_TIMER bool "Use PIT timer" + select VF_PIT_TIMER help Use SoC Periodic Interrupt Timer (PIT) as clocksource