Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755524Ab3GUOJS (ORCPT ); Sun, 21 Jul 2013 10:09:18 -0400 Received: from smtp.citrix.com ([66.165.176.89]:34856 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755489Ab3GUOJQ (ORCPT ); Sun, 21 Jul 2013 10:09:16 -0400 X-IronPort-AV: E=Sophos;i="4.89,713,1367971200"; d="scan'208";a="38300140" Date: Sun, 21 Jul 2013 15:09:13 +0100 From: Stefano Stabellini X-X-Sender: sstabellini@kaball.uk.xensource.com To: Julien Grall CC: , , , , , , Subject: Re: [PATCH v2] xen/arm: disable cpuidle and cpufreq when linux is running as dom0 In-Reply-To: <1374233220-13770-1-git-send-email-julien.grall@linaro.org> Message-ID: References: <1374233220-13770-1-git-send-email-julien.grall@linaro.org> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1590 Lines: 54 On Fri, 19 Jul 2013, Julien Grall wrote: > When linux is running as dom0, Xen doesn't show the physical cpu but a > virtual CPU. > On some ARM SOC (for instance the exynos 5250), linux registers callbacks > for cpuidle and cpufreq. When these callbacks are called, they will modify > directly the physical cpu not the virtual one. It can impact the whole board > instead of only dom0. > > Signed-off-by: Julien Grall > Acked-by: Stefano Stabellini > Changes in v2: > - Disable cpufreq > --- > arch/arm/xen/enlighten.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > index 49839d8..af82792 100644 > --- a/arch/arm/xen/enlighten.c > +++ b/arch/arm/xen/enlighten.c > @@ -24,6 +24,8 @@ > #include > #include > #include > +#include > +#include > > #include > > @@ -292,6 +294,12 @@ static int __init xen_pm_init(void) > { > pm_power_off = xen_power_off; > arm_pm_restart = xen_restart; > + /* > + * Making sure board specific code will not set up ops for > + * cpu idle and cpu freq. > + */ > + disable_cpuidle(); > + disable_cpufreq(); > > return 0; > } > -- > 1.7.10.4 > -- 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/