From patchwork Wed Oct 21 19:12:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Rafael J. Wysocki" X-Patchwork-Id: 286750 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F15DBC56201 for ; Wed, 21 Oct 2020 19:14:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9EF372416E for ; Wed, 21 Oct 2020 19:14:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2409606AbgJUTOi (ORCPT ); Wed, 21 Oct 2020 15:14:38 -0400 Received: from cloudserver094114.home.pl ([79.96.170.134]:63870 "EHLO cloudserver094114.home.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2504797AbgJUTOg (ORCPT ); Wed, 21 Oct 2020 15:14:36 -0400 Received: from 89-77-60-66.dynamic.chello.pl (89.77.60.66) (HELO kreacher.localnet) by serwer1319399.home.pl (79.96.170.134) with SMTP (IdeaSmtpServer 0.83.491) id 030494657aca0941; Wed, 21 Oct 2020 21:14:32 +0200 From: "Rafael J. Wysocki" To: Greg Kroah-Hartman Cc: Linux PM , LKML , Lukas Wunner , Saravana Kannan , Xiang Chen Subject: [PATCH 1/3] PM: runtime: Drop runtime PM references to supplier on link removal Date: Wed, 21 Oct 2020 21:12:15 +0200 Message-ID: <1682736.0MbBAd5gSP@kreacher> In-Reply-To: <6543936.FbWAdBN1tG@kreacher> References: <6543936.FbWAdBN1tG@kreacher> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Rafael J. Wysocki While removing a device link, drop the supplier device's runtime PM usage counter as many times as needed to drop all of the runtime PM references to it from the consumer in addition to dropping the consumer's link count. Fixes: baa8809f6097 ("PM / runtime: Optimize the use of device links") Signed-off-by: Rafael J. Wysocki Cc: 5.1+ # 5.1+ --- drivers/base/core.c | 6 ++---- drivers/base/power/runtime.c | 21 ++++++++++++++++++++- include/linux/pm_runtime.h | 4 ++-- 3 files changed, 24 insertions(+), 7 deletions(-) Index: linux-pm/drivers/base/power/runtime.c =================================================================== --- linux-pm.orig/drivers/base/power/runtime.c +++ linux-pm/drivers/base/power/runtime.c @@ -1729,7 +1729,7 @@ void pm_runtime_new_link(struct device * spin_unlock_irq(&dev->power.lock); } -void pm_runtime_drop_link(struct device *dev) +static void pm_runtime_drop_link_count(struct device *dev) { spin_lock_irq(&dev->power.lock); WARN_ON(dev->power.links_count == 0); @@ -1737,6 +1737,25 @@ void pm_runtime_drop_link(struct device spin_unlock_irq(&dev->power.lock); } +/** + * pm_runtime_drop_link - Prepare for device link removal. + * @link: Device link going away. + * + * Drop the link count of the consumer end of @link and decrement the supplier + * device's runtime PM usage counter as many times as needed to drop all of the + * PM runtime reference to it from the consumer. + */ +void pm_runtime_drop_link(struct device_link *link) +{ + if (!(link->flags & DL_FLAG_PM_RUNTIME)) + return; + + pm_runtime_drop_link_count(link->consumer); + + while (refcount_dec_not_one(&link->rpm_active)) + pm_runtime_put(link->supplier); +} + static bool pm_runtime_need_not_resume(struct device *dev) { return atomic_read(&dev->power.usage_count) <= 1 && Index: linux-pm/include/linux/pm_runtime.h =================================================================== --- linux-pm.orig/include/linux/pm_runtime.h +++ linux-pm/include/linux/pm_runtime.h @@ -58,7 +58,7 @@ extern void pm_runtime_clean_up_links(st extern void pm_runtime_get_suppliers(struct device *dev); extern void pm_runtime_put_suppliers(struct device *dev); extern void pm_runtime_new_link(struct device *dev); -extern void pm_runtime_drop_link(struct device *dev); +extern void pm_runtime_drop_link(struct device_link *link); /** * pm_runtime_get_if_in_use - Conditionally bump up runtime PM usage counter. @@ -280,7 +280,7 @@ static inline void pm_runtime_clean_up_l static inline void pm_runtime_get_suppliers(struct device *dev) {} static inline void pm_runtime_put_suppliers(struct device *dev) {} static inline void pm_runtime_new_link(struct device *dev) {} -static inline void pm_runtime_drop_link(struct device *dev) {} +static inline void pm_runtime_drop_link(struct device_link *link) {} #endif /* !CONFIG_PM */ Index: linux-pm/drivers/base/core.c =================================================================== --- linux-pm.orig/drivers/base/core.c +++ linux-pm/drivers/base/core.c @@ -763,8 +763,7 @@ static void __device_link_del(struct kre dev_dbg(link->consumer, "Dropping the link to %s\n", dev_name(link->supplier)); - if (link->flags & DL_FLAG_PM_RUNTIME) - pm_runtime_drop_link(link->consumer); + pm_runtime_drop_link(link); list_del_rcu(&link->s_node); list_del_rcu(&link->c_node); @@ -778,8 +777,7 @@ static void __device_link_del(struct kre dev_info(link->consumer, "Dropping the link to %s\n", dev_name(link->supplier)); - if (link->flags & DL_FLAG_PM_RUNTIME) - pm_runtime_drop_link(link->consumer); + pm_runtime_drop_link(link); list_del(&link->s_node); list_del(&link->c_node);