From patchwork Sun Jul 31 17:49:12 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Rafael Wysocki X-Patchwork-Id: 1023992 Received: from smtp1.linux-foundation.org (smtp1.linux-foundation.org [140.211.169.13]) by demeter1.kernel.org (8.14.4/8.14.4) with ESMTP id p6VHsO0q006795 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=FAIL) for ; Sun, 31 Jul 2011 17:54:45 GMT Received: from daredevil.linux-foundation.org (localhost [127.0.0.1]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id p6VHr0AX027793; Sun, 31 Jul 2011 10:53:01 -0700 Received: from ogre.sisk.pl (ogre.sisk.pl [217.79.144.158]) by smtp1.linux-foundation.org (8.14.2/8.13.5/Debian-3ubuntu1.1) with ESMTP id p6VHquZN027772 for ; Sun, 31 Jul 2011 10:52:58 -0700 Received: from localhost (localhost.localdomain [127.0.0.1]) by ogre.sisk.pl (Postfix) with ESMTP id 197A71B6B9C; Sun, 31 Jul 2011 19:18:55 +0200 (CEST) Received: from ogre.sisk.pl ([127.0.0.1]) by localhost (ogre.sisk.pl [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 28111-05; Sun, 31 Jul 2011 19:18:23 +0200 (CEST) Received: from ferrari.rjw.lan (220-bem-13.acn.waw.pl [82.210.184.220]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by ogre.sisk.pl (Postfix) with ESMTP id D850F1B6C37; Sun, 31 Jul 2011 19:18:22 +0200 (CEST) From: "Rafael J. Wysocki" To: Linux PM mailing list Date: Sun, 31 Jul 2011 19:49:12 +0200 User-Agent: KMail/1.13.6 (Linux/3.0.0+; KDE/4.6.0; x86_64; ; ) References: <201107311946.06654.rjw@sisk.pl> In-Reply-To: <201107311946.06654.rjw@sisk.pl> MIME-Version: 1.0 Message-Id: <201107311949.12503.rjw@sisk.pl> X-Virus-Scanned: amavisd-new at ogre.sisk.pl using MkS_Vir for Linux Received-SPF: pass (localhost is always allowed.) X-Spam-Status: No, hits=-3.93 required=5 tests=AWL, BAYES_00, OSDL_HEADER_SUBJECT_BRACKETED X-Spam-Checker-Version: SpamAssassin 3.2.4-osdl_revision__1.47__ X-MIMEDefang-Filter: lf$Revision: 1.188 $ X-Scanned-By: MIMEDefang 2.63 on 140.211.169.21 Cc: LKML , linux-sh@vger.kernel.org Subject: [linux-pm] [PATCH 4/9] PM / Domains: Make pm_genpd_poweron() always survive parent removal X-BeenThere: linux-pm@lists.linux-foundation.org X-Mailman-Version: 2.1.9 Precedence: list List-Id: Linux power management List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org X-Greylist: IP, sender and recipient auto-whitelisted, not delayed by milter-greylist-4.2.6 (demeter1.kernel.org [140.211.167.41]); Sun, 31 Jul 2011 17:54:45 +0000 (UTC) From: Rafael J. Wysocki If pm_genpd_remove_subdomain() is called to remove a PM domain's subdomain and pm_genpd_poweron() is called for that subdomain at the same time, and the pm_genpd_poweron() called by it recursively for the parent returns an error, the first pm_genpd_poweron()'s error code path will attempt to decrement the subdomain counter of a PM domain that it's not a subdomain of any more. Rearrange the code in pm_genpd_poweron() to prevent this from happening. Signed-off-by: Rafael J. Wysocki --- drivers/base/power/domain.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) Index: linux-2.6/drivers/base/power/domain.c =================================================================== --- linux-2.6.orig/drivers/base/power/domain.c +++ linux-2.6/drivers/base/power/domain.c @@ -89,12 +89,14 @@ static void genpd_set_active(struct gene */ int pm_genpd_poweron(struct generic_pm_domain *genpd) { - struct generic_pm_domain *parent = genpd->parent; + struct generic_pm_domain *parent; int ret = 0; - start: mutex_lock(&genpd->lock); + parent = genpd->parent; + + start: if (genpd->status == GPD_STATE_ACTIVE || (genpd->prepared_count > 0 && genpd->suspend_power_off)) goto out; @@ -110,29 +112,34 @@ int pm_genpd_poweron(struct generic_pm_d mutex_unlock(&genpd->lock); ret = pm_genpd_poweron(parent); - if (ret) { - genpd_sd_counter_dec(parent); - return ret; - } + + mutex_lock(&genpd->lock); + + if (ret) + goto err; parent = NULL; goto start; } - if (genpd->power_on) + if (genpd->power_on) { ret = genpd->power_on(genpd); - - if (ret) { - if (genpd->parent) - genpd_sd_counter_dec(genpd->parent); - } else { - genpd_set_active(genpd); + if (ret) + goto err; } + genpd_set_active(genpd); + out: mutex_unlock(&genpd->lock); return ret; + + err: + if (genpd->parent) + genpd_sd_counter_dec(genpd->parent); + + goto out; } #endif /* CONFIG_PM */