From patchwork Fri Jan 24 09:28:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 233242 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 BB8E5C2D0DB for ; Fri, 24 Jan 2020 09:47:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8F4772087E for ; Fri, 24 Jan 2020 09:47:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579859274; bh=wwfrqVSElqD2J9lqJC+Y6J/tNlLKq0K7yDsR37nexT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ZEmRKkyeh+mTqb9/sibn8QmBPjLFwav3oN6Ol0pt6t/H5NxVA+bCyojSesx6tLKZO bgqR4ufJKkn2nj3lSXyHg4p7dLwve3CvDf1hkMKlhUUgW8glQhU/tpPJNO4off9i7P lophdUJx3Lzwmh5bB6V0XnaVTT5PQkGloaU77n/8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387666AbgAXJrt (ORCPT ); Fri, 24 Jan 2020 04:47:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:47750 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387676AbgAXJrt (ORCPT ); Fri, 24 Jan 2020 04:47:49 -0500 Received: from localhost (unknown [145.15.244.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 38F85206D5; Fri, 24 Jan 2020 09:47:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579859268; bh=wwfrqVSElqD2J9lqJC+Y6J/tNlLKq0K7yDsR37nexT4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cy5XQ1oIRVtsH8kVFUfJtHa7+H1dZNEVk6By7rdYt4URrW4b2u8harNdGcBNLul4V miGloTu8B/5/pfeTsGcMWDz+I7ri6fyw3gMqpZxeQib000z8P1kyYVk59cZOTw7RBb LXHgtvDc+Sxag9wdZRv3vyTlKE/qYs4zmO3b/kYs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 4.14 081/343] driver core: Do not resume suppliers under device_links_write_lock() Date: Fri, 24 Jan 2020 10:28:19 +0100 Message-Id: <20200124092930.601494941@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124092919.490687572@linuxfoundation.org> References: <20200124092919.490687572@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Rafael J. Wysocki [ Upstream commit 5db25c9eb893df8f6b93c1d97b8006d768e1b6f5 ] It is incorrect to call pm_runtime_get_sync() under device_links_write_lock(), because it may end up trying to take device_links_read_lock() while resuming the target device and that will deadlock in the non-SRCU case, so avoid that by resuming the supplier device in device_link_add() before calling device_links_write_lock(). Fixes: 21d5c57b3726 ("PM / runtime: Use device links") Fixes: baa8809f6097 ("PM / runtime: Optimize the use of device links") Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/base/core.c | 20 ++++++++++++++------ 1 file changed, 14 insertions(+), 6 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 2b0a1054535ce..93c2fc58013ed 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -180,11 +180,20 @@ struct device_link *device_link_add(struct device *consumer, struct device *supplier, u32 flags) { struct device_link *link; + bool rpm_put_supplier = false; if (!consumer || !supplier || ((flags & DL_FLAG_STATELESS) && (flags & DL_FLAG_AUTOREMOVE))) return NULL; + if (flags & DL_FLAG_PM_RUNTIME && flags & DL_FLAG_RPM_ACTIVE) { + if (pm_runtime_get_sync(supplier) < 0) { + pm_runtime_put_noidle(supplier); + return NULL; + } + rpm_put_supplier = true; + } + device_links_write_lock(); device_pm_lock(); @@ -209,13 +218,8 @@ struct device_link *device_link_add(struct device *consumer, if (flags & DL_FLAG_PM_RUNTIME) { if (flags & DL_FLAG_RPM_ACTIVE) { - if (pm_runtime_get_sync(supplier) < 0) { - pm_runtime_put_noidle(supplier); - kfree(link); - link = NULL; - goto out; - } link->rpm_active = true; + rpm_put_supplier = false; } pm_runtime_new_link(consumer); /* @@ -286,6 +290,10 @@ struct device_link *device_link_add(struct device *consumer, out: device_pm_unlock(); device_links_write_unlock(); + + if (rpm_put_supplier) + pm_runtime_put(supplier); + return link; } EXPORT_SYMBOL_GPL(device_link_add);