From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755328AbbAZKjR (ORCPT ); Mon, 26 Jan 2015 05:39:17 -0500 Received: from mga11.intel.com ([192.55.52.93]:8096 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755277AbbAZKjL convert rfc822-to-8bit (ORCPT ); Mon, 26 Jan 2015 05:39:11 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.09,468,1418112000"; d="scan'208";a="667550899" From: "Liu, Chuansheng" To: Pavel Machek , "Fu, Zhonghui" CC: "Rafael J. Wysocki" , "Brown, Len" , Greg Kroah-Hartman , "linux-pm@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: RE: Change behaviour when tracing ... nasty trap (was Re: [PATCH] PM/Trace: get rid of synchronous resume limit during PM trace) Thread-Topic: Change behaviour when tracing ... nasty trap (was Re: [PATCH] PM/Trace: get rid of synchronous resume limit during PM trace) Thread-Index: AQHQOVI4WhHuql6TR0OwGyzNDtsW5ZzSNSqA Date: Mon, 26 Jan 2015 10:39:04 +0000 Message-ID: <27240C0AC20F114CBF8149A2696CBE4A01F1AD6A@SHSMSX101.ccr.corp.intel.com> References: <54C5CB77.4000109@linux.intel.com> <20150126102352.GA1758@amd> In-Reply-To: <20150126102352.GA1758@amd> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello Pavel, > -----Original Message----- > From: Pavel Machek [mailto:pavel@ucw.cz] > Sent: Monday, January 26, 2015 6:24 PM > To: Fu, Zhonghui > Cc: Rafael J. Wysocki; Brown, Len; Greg Kroah-Hartman; > linux-pm@vger.kernel.org; linux-kernel@vger.kernel.org; Liu, Chuansheng > Subject: Change behaviour when tracing ... nasty trap (was Re: [PATCH] > PM/Trace: get rid of synchronous resume limit during PM trace) > > On Mon 2015-01-26 13:07:03, Fu, Zhonghui wrote: > > >From f9c841d1f943d81b5ab0aac7483e794a7f966296 Mon Sep 17 00:00:00 > 2001 > > From: Zhonghui Fu > > Date: Mon, 26 Jan 2015 11:27:08 +0800 > > Subject: [PATCH] PM/Trace: get rid of synchronous resume limit during PM > trace > > > > There are some kind of dependency between devices in some > > hardware platforms. So, asynchronous resuming devices may > > hang system due to wrong resume order. As a result, should > > not fore synchronously resuming devices during tracing > > PM events. > > > > Signed-off-by: Zhonghui Fu > > --- > > drivers/base/power/main.c | 3 +-- > > include/linux/resume-trace.h | 7 ------- > > 2 files changed, 1 insertions(+), 9 deletions(-) > > > > diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c > > index 9717d5f..5df148b 100644 > > --- a/drivers/base/power/main.c > > +++ b/drivers/base/power/main.c > > @@ -517,8 +517,7 @@ static int device_resume_noirq(struct device *dev, > pm_message_t state, bool asyn > > > > static bool is_async(struct device *dev) > > { > > - return dev->power.async_suspend && pm_async_enabled > > - && !pm_trace_is_enabled(); > > + return dev->power.async_suspend && pm_async_enabled; > > } > > > > Actually... whoever did the original patch was evil person. Changing > behaviour when tracing is requested is evil, evil, evil. Git blame > tells me > > Signed-off-by: Chuansheng Liu > > went to the dark side. Although I didn't get where is something wrong, but the is_async() is not created by my commit, it is from commit (PM: Start asynchronous resume threads upfront), I just moved it ahead. And like other phases, I added it into resum/suspend_noirq()...