From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FE12C43334 for ; Tue, 28 Jun 2022 01:53:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243303AbiF1Bxh (ORCPT ); Mon, 27 Jun 2022 21:53:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39410 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243289AbiF1Bxh (ORCPT ); Mon, 27 Jun 2022 21:53:37 -0400 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BF8BDB860; Mon, 27 Jun 2022 18:53:35 -0700 (PDT) X-UUID: 59c97e923145422c9af9f4e65f313468-20220628 X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.7,REQID:340a9956-5ffe-49e2-a147-fe9a61b949f0,OB:0,LO B:0,IP:0,URL:5,TC:0,Content:0,EDM:0,RT:0,SF:51,FILE:0,RULE:Release_Ham,ACT ION:release,TS:56 X-CID-INFO: VERSION:1.1.7,REQID:340a9956-5ffe-49e2-a147-fe9a61b949f0,OB:0,LOB: 0,IP:0,URL:5,TC:0,Content:0,EDM:0,RT:0,SF:51,FILE:0,RULE:Release_Ham,ACTIO N:release,TS:56 X-CID-META: VersionHash:87442a2,CLOUDID:3b3cfed5-5d6d-4eaf-a635-828a3ee48b7c,C OID:ecf55dad5c57,Recheck:0,SF:28|17|19|48,TC:nil,Content:0,EDM:-3,IP:nil,U RL:1,File:nil,QS:nil,BEC:nil,COL:0 X-UUID: 59c97e923145422c9af9f4e65f313468-20220628 Received: from mtkcas11.mediatek.inc [(172.21.101.40)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-SHA384 256/256) with ESMTP id 276109738; Tue, 28 Jun 2022 09:53:31 +0800 Received: from mtkcas10.mediatek.inc (172.21.101.39) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384) id 15.2.792.3; Tue, 28 Jun 2022 09:53:31 +0800 Received: from [172.21.84.99] (172.21.84.99) by mtkcas10.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.0.1497.2 via Frontend Transport; Tue, 28 Jun 2022 09:53:30 +0800 Subject: Re: [PATCH v1] PM-runtime: Check supplier_preactivated before release supplier To: "Rafael J. Wysocki" CC: Matthias Brugger , Len Brown , Pavel Machek , Greg Kroah-Hartman , Stanley Chu , "Linux ARM" , Linux Kernel Mailing List , Linux PM , "Martin K. Petersen" , Avri Altman , Alim Akhtar , "James E.J. Bottomley" , wsd_upstream , "moderated list:ARM/Mediatek SoC..." , , , , , , , , , References: <20220613120755.14306-1-peter.wang@mediatek.com> From: Peter Wang Message-ID: <028eba89-8176-740f-42df-736a0fcf26e7@mediatek.com> Date: Tue, 28 Jun 2022 09:53:31 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-US Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 6/28/22 3:00 AM, Rafael J. Wysocki wrote: > On Mon, Jun 13, 2022 at 2:08 PM wrote: >> From: Peter Wang >> >> With divice link of DL_FLAG_PM_RUNTIME, if consumer call pm_runtime_get_suppliers >> to prevent supplier enter suspend, pm_runtime_release_supplier should >> check supplier_preactivated before let supplier enter suspend. > Why? because supplier_preactivated is true means supplier cannot enter suspend, right? >> If the link is drop or release, bypass check supplier_preactivated. >> >> Signed-off-by: Peter Wang >> --- >> drivers/base/core.c | 2 +- >> drivers/base/power/runtime.c | 15 ++++++++++++--- >> include/linux/pm_runtime.h | 5 +++-- >> 3 files changed, 16 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/base/core.c b/drivers/base/core.c >> index 7cd789c4985d..3b9cc559928f 100644 >> --- a/drivers/base/core.c >> +++ b/drivers/base/core.c >> @@ -486,7 +486,7 @@ static void device_link_release_fn(struct work_struct *work) >> /* Ensure that all references to the link object have been dropped. */ >> device_link_synchronize_removal(); >> >> - pm_runtime_release_supplier(link, true); >> + pm_runtime_release_supplier(link, true, true); >> >> put_device(link->consumer); >> put_device(link->supplier); >> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c >> index 676dc72d912d..3c4f425937a1 100644 >> --- a/drivers/base/power/runtime.c >> +++ b/drivers/base/power/runtime.c >> @@ -314,10 +314,19 @@ static int rpm_get_suppliers(struct device *dev) >> * and if @check_idle is set, check if that device is idle (and so it can be >> * suspended). >> */ >> -void pm_runtime_release_supplier(struct device_link *link, bool check_idle) >> +void pm_runtime_release_supplier(struct device_link *link, bool check_idle, >> + bool drop) >> { >> struct device *supplier = link->supplier; >> >> + /* >> + * When consumer hold supplier, supplier cannot enter suspend. >> + * Driect release supplier and let supplier enter suspend is not allow. >> + * Unless the link is drop, direct relsease supplier should be okay. >> + */ >> + if (link->supplier_preactivated && !drop) >> + return; >> + >> /* >> * The additional power.usage_count check is a safety net in case >> * the rpm_active refcount becomes saturated, in which case >> @@ -338,7 +347,7 @@ static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend) >> >> list_for_each_entry_rcu(link, &dev->links.suppliers, c_node, >> device_links_read_lock_held()) >> - pm_runtime_release_supplier(link, try_to_suspend); >> + pm_runtime_release_supplier(link, try_to_suspend, false); >> } >> >> static void rpm_put_suppliers(struct device *dev) >> @@ -1838,7 +1847,7 @@ void pm_runtime_drop_link(struct device_link *link) >> return; >> >> pm_runtime_drop_link_count(link->consumer); >> - pm_runtime_release_supplier(link, true); >> + pm_runtime_release_supplier(link, true, true); >> } >> >> static bool pm_runtime_need_not_resume(struct device *dev) >> diff --git a/include/linux/pm_runtime.h b/include/linux/pm_runtime.h >> index 9e4d056967c6..354ffb1eaec0 100644 >> --- a/include/linux/pm_runtime.h >> +++ b/include/linux/pm_runtime.h >> @@ -88,7 +88,8 @@ 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_link *link); >> -extern void pm_runtime_release_supplier(struct device_link *link, bool check_idle); >> +extern void pm_runtime_release_supplier(struct device_link *link, >> + bool check_idle, bool drop); >> >> extern int devm_pm_runtime_enable(struct device *dev); >> >> @@ -315,7 +316,7 @@ 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_link *link) {} >> static inline void pm_runtime_release_supplier(struct device_link *link, >> - bool check_idle) {} >> + bool check_idle, bool drop) {} >> >> #endif /* !CONFIG_PM */ >> >> -- >> 2.18.0 >>