From patchwork Mon Mar 29 07:58:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 412689 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham 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 EA9A5C433EA for ; Mon, 29 Mar 2021 08:17:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C648461964 for ; Mon, 29 Mar 2021 08:17:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232921AbhC2IQs (ORCPT ); Mon, 29 Mar 2021 04:16:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:57718 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232649AbhC2IPZ (ORCPT ); Mon, 29 Mar 2021 04:15:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4625E6196F; Mon, 29 Mar 2021 08:15:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617005710; bh=Pf2xNTUq12l5bnQpmGq8y4E++VIqfcc8+2qazkxsO6A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KEahPYN0QxYx7Xep6nPz8PLQlKr2rPZj692/9W44CcZp805sn+WcHPXMwgoBGL8/E GkpLLrdUKRKGMfHO86vEyk/jna9dqP3vHODFZYqGr2AeyrNFPWZ8gsZNb12ReFXv8c 278R4URGUdLjbqLdNibOyIGKb5imPBBkvWmsv/YA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "elaine.zhang" , Ulf Hansson , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.4 089/111] PM: runtime: Defer suspending suppliers Date: Mon, 29 Mar 2021 09:58:37 +0200 Message-Id: <20210329075618.179060849@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210329075615.186199980@linuxfoundation.org> References: <20210329075615.186199980@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Rafael J. Wysocki [ Upstream commit 5244f5e2d801259af877ee759e8c22364c607072 ] Because the PM-runtime status of the device is not updated in __rpm_callback(), attempts to suspend the suppliers of the given device triggered by the rpm_put_suppliers() call in there may cause a supplier to be suspended completely before the status of the consumer is updated to RPM_SUSPENDED, which is confusing. To avoid that (1) modify __rpm_callback() to only decrease the PM-runtime usage counter of each supplier and (2) make rpm_suspend() try to suspend the suppliers after changing the consumer's status to RPM_SUSPENDED, in analogy with the device's parent. Link: https://lore.kernel.org/linux-pm/CAPDyKFqm06KDw_p8WXsM4dijDbho4bb6T4k50UqqvR1_COsp8g@mail.gmail.com/ Fixes: 21d5c57b3726 ("PM / runtime: Use device links") Reported-by: elaine.zhang Diagnosed-by: Ulf Hansson Reviewed-by: Ulf Hansson Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/base/power/runtime.c | 45 +++++++++++++++++++++++++++++++----- 1 file changed, 39 insertions(+), 6 deletions(-) diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index 137a7ba053d7..e0c4ef06ca91 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -305,7 +305,7 @@ static int rpm_get_suppliers(struct device *dev) return 0; } -static void rpm_put_suppliers(struct device *dev) +static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend) { struct device_link *link; @@ -313,10 +313,30 @@ static void rpm_put_suppliers(struct device *dev) device_links_read_lock_held()) { while (refcount_dec_not_one(&link->rpm_active)) - pm_runtime_put(link->supplier); + pm_runtime_put_noidle(link->supplier); + + if (try_to_suspend) + pm_request_idle(link->supplier); } } +static void rpm_put_suppliers(struct device *dev) +{ + __rpm_put_suppliers(dev, true); +} + +static void rpm_suspend_suppliers(struct device *dev) +{ + struct device_link *link; + int idx = device_links_read_lock(); + + list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, + device_links_read_lock_held()) + pm_request_idle(link->supplier); + + device_links_read_unlock(idx); +} + /** * __rpm_callback - Run a given runtime PM callback for a given device. * @cb: Runtime PM callback to run. @@ -344,8 +364,10 @@ static int __rpm_callback(int (*cb)(struct device *), struct device *dev) idx = device_links_read_lock(); retval = rpm_get_suppliers(dev); - if (retval) + if (retval) { + rpm_put_suppliers(dev); goto fail; + } device_links_read_unlock(idx); } @@ -368,9 +390,9 @@ static int __rpm_callback(int (*cb)(struct device *), struct device *dev) || (dev->power.runtime_status == RPM_RESUMING && retval))) { idx = device_links_read_lock(); - fail: - rpm_put_suppliers(dev); + __rpm_put_suppliers(dev, false); +fail: device_links_read_unlock(idx); } @@ -644,8 +666,11 @@ static int rpm_suspend(struct device *dev, int rpmflags) goto out; } + if (dev->power.irq_safe) + goto out; + /* Maybe the parent is now able to suspend. */ - if (parent && !parent->power.ignore_children && !dev->power.irq_safe) { + if (parent && !parent->power.ignore_children) { spin_unlock(&dev->power.lock); spin_lock(&parent->power.lock); @@ -654,6 +679,14 @@ static int rpm_suspend(struct device *dev, int rpmflags) spin_lock(&dev->power.lock); } + /* Maybe the suppliers are now able to suspend. */ + if (dev->power.links_count > 0) { + spin_unlock_irq(&dev->power.lock); + + rpm_suspend_suppliers(dev); + + spin_lock_irq(&dev->power.lock); + } out: trace_rpm_return_int_rcuidle(dev, _THIS_IP_, retval);