Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964908AbbD0SCC (ORCPT ); Mon, 27 Apr 2015 14:02:02 -0400 Received: from mail-lb0-f171.google.com ([209.85.217.171]:36050 "EHLO mail-lb0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933101AbbD0SB7 (ORCPT ); Mon, 27 Apr 2015 14:01:59 -0400 MIME-Version: 1.0 In-Reply-To: <20150425201225.GB3008@amd> References: <1429750212-28659-1-git-send-email-jinqian@android.com> <1429750212-28659-2-git-send-email-jinqian@android.com> <20150425201225.GB3008@amd> Date: Mon, 27 Apr 2015 11:01:58 -0700 Message-ID: Subject: Re: [PATCH 1/3] power: validate wakeup source before activating it. From: Jin Qian To: Pavel Machek Cc: "Rafael J. Wysocki" , Len Brown , Greg Kroah-Hartman , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2950 Lines: 81 This is a rare case. My thought is to prevent a rogue wakeup source from preventing system suspend, which is very difficult to find out if the wakeup source is not registered and not visible in /d/wakeup_sources. On the other hand, if the wakeup source failed to activate, it's much easier to be noticed considering we deal with particular wakeup source. I can make the pr_err BUG_ON or WARN_ON if they're more noticeable. Thanks, jin On Sat, Apr 25, 2015 at 1:12 PM, Pavel Machek wrote: > On Wed 2015-04-22 17:50:10, Jin Qian wrote: >> A rogue wakeup source not registered in wakeup_sources list is not visible >> from wakeup_sources_stats_show. Check if the wakeup source is registered >> properly by looking at the timer function. > > How often does that happen? > > Will people on your systems actually notice that pr_err()? > Pavel > >> Signed-off-by: Jin Qian >> --- >> drivers/base/power/wakeup.c | 19 +++++++++++++++++++ >> 1 file changed, 19 insertions(+) >> >> diff --git a/drivers/base/power/wakeup.c b/drivers/base/power/wakeup.c >> index 7726200..f24c622 100644 >> --- a/drivers/base/power/wakeup.c >> +++ b/drivers/base/power/wakeup.c >> @@ -14,6 +14,7 @@ >> #include >> #include >> #include >> +#include >> #include >> >> #include "power.h" >> @@ -351,6 +352,19 @@ int device_set_wakeup_enable(struct device *dev, bool enable) >> } >> EXPORT_SYMBOL_GPL(device_set_wakeup_enable); >> >> +/** >> + * validate_wakeup_source - validate the given wakeup source. >> + * @ws: Wakeup source to be validated. >> + */ >> +static bool validate_wakeup_source(struct wakeup_source *ws) >> +{ >> + /* >> + * Use timer function to check if the given source is initialized >> + * by wakeup_source_add. >> + */ >> + return ws->timer.function == pm_wakeup_timer_fn; >> +} >> + >> /* >> * The functions below use the observation that each wakeup event starts a >> * period in which the system should not be suspended. The moment this period >> @@ -391,6 +405,11 @@ static void wakeup_source_activate(struct wakeup_source *ws) >> { >> unsigned int cec; >> >> + if (!validate_wakeup_source(ws)) { >> + pr_err("unregistered wakeup source: %s\n", ws->name); >> + return; >> + } >> + >> /* >> * active wakeup source should bring the system >> * out of PM_SUSPEND_FREEZE state > > -- > (english) http://www.livejournal.com/~pavelmachek > (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- 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/