From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755490Ab2DKKLF (ORCPT ); Wed, 11 Apr 2012 06:11:05 -0400 Received: from www.linutronix.de ([62.245.132.108]:57890 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752846Ab2DKKLE (ORCPT ); Wed, 11 Apr 2012 06:11:04 -0400 Date: Wed, 11 Apr 2012 12:10:59 +0200 (CEST) From: Thomas Gleixner To: Feng Tang cc: suresh.b.siddha@intel.com, santosh.shilimkar@ti.com, linux-kernel@vger.kernel.org, johnstul@us.ibm.com Subject: Re: [PATCH] clockevents: Leave broadcast device shtudown only if the current device is always running. In-Reply-To: <20120411063452.GA25399@feng-i7> Message-ID: References: <1333951423-27621-1-git-send-email-santosh.shilimkar@ti.com> <1334011304.12400.81.camel@sbsiddha-desk.sc.intel.com> <20120411063452.GA25399@feng-i7> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 11 Apr 2012, Feng Tang wrote: > > Problem you encountered is not related to leaving the broadcast device > > in shutdown mode. Problem is that we didn't track the mode change to > > oneshot and later during idle entry/exit, when we request the broadcast > > device services using CLOCK_EVT_NOTIFY_BROADCAST_ENTER etc, > > tick_broadcast_oneshot_control() returns with out doing much as it > > thinks broadcast device is in periodic mode. > > Just curious, IIUC, the tick_broadcast_switch_to_oneshot() is only called > during CPU init process in boot time or bring a offlined cpu back on. Why > is it related to the deep idle? Because a deep idle state might require the broadcast device and w/o Suresh's patch it can't use it because it's in the wrong state. Thanks, tglx