From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752686AbaIYHvY (ORCPT ); Thu, 25 Sep 2014 03:51:24 -0400 Received: from mail-bn1bn0108.outbound.protection.outlook.com ([157.56.110.108]:35452 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752586AbaIYHvU (ORCPT ); Thu, 25 Sep 2014 03:51:20 -0400 Date: Thu, 25 Sep 2014 15:50:15 +0800 From: Shawn Guo To: Stefan Agner CC: , , , , Subject: Re: [PATCH 2/2] ARM: vf610: Use ARM Global Timer as clocksource Message-ID: <20140925075013.GD6405@dragon> References: <1410437175-6636-1-git-send-email-stefan@agner.ch> <1410437175-6636-2-git-send-email-stefan@agner.ch> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1410437175-6636-2-git-send-email-stefan@agner.ch> User-Agent: Mutt/1.5.21 (2010-09-15) X-Originating-IP: [180.108.234.93] X-ClientProxiedBy: HKXPR01CA007.apcprd01.prod.exchangelabs.com (10.242.96.17) To BLUPR03MB342.namprd03.prod.outlook.com (10.141.48.13) X-Microsoft-Antispam: UriScan:; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;SRVR:BLUPR03MB342; X-Forefront-PRVS: 0345CFD558 X-Forefront-Antispam-Report: SFV:NSPM;SFS:(10019020)(6009001)(189002)(24454002)(51704005)(199003)(83506001)(120916001)(106356001)(107046002)(10300001)(19580405001)(46406003)(19580395003)(66066001)(97756001)(85852003)(83322001)(42186005)(83072002)(81542003)(31966008)(47776003)(20776003)(46102003)(77982003)(80022003)(90102001)(85306004)(74662003)(64706001)(74502003)(79102003)(81342003)(21056001)(95666004)(33656002)(86362001)(97736003)(102836001)(110136001)(99396003)(87976001)(92566001)(92726001)(23726002)(4396001)(33716001)(50466002)(105586002)(101416001)(76482002)(76176999)(50986999)(54356999)(77096002);DIR:OUT;SFP:1102;SCL:1;SRVR:BLUPR03MB342;H:dragon;FPR:;MLV:sfv;PTR:InfoNoRecords;MX:1;A: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 Thu, Sep 11, 2014 at 02:06:15PM +0200, Stefan Agner wrote: > Use ARM Global Timer as clocksource instead of the PIT timer. 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. I just think of one thing. Will this change cause a problem of the low power idle support in case we want to power down ARM core in there? Shawn > > Signed-off-by: Stefan Agner > --- > Theoretically we could remove the PIT driver now. But we could also > enable both drivers, but is having two clock source useful for the > Kernel at all? > > arch/arm/mach-imx/Kconfig | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/arm/mach-imx/Kconfig b/arch/arm/mach-imx/Kconfig > index 64161aa..adc77180 100644 > --- a/arch/arm/mach-imx/Kconfig > +++ b/arch/arm/mach-imx/Kconfig > @@ -656,7 +656,8 @@ config SOC_VF610 > bool "Vybrid Family VF610 support" > select ARM_GIC > select PINCTRL_VF610 > - select VF_PIT_TIMER > + select ARM_GLOBAL_TIMER > + select CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK > select PL310_ERRATA_769419 if CACHE_L2X0 > > help > -- > 2.1.0 >