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 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=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 C360EC32771 for ; Fri, 24 Jan 2020 11:08:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9BA1C2075D for ; Fri, 24 Jan 2020 11:08:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864128; bh=eWRkYCS1XL9YkNnhsGLKtC1fiZMMAWnLCQqSNCv2kcA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=rJuUTsaNKQ3vOOT8bGLrvF04g5Hq/aftESeGIKF3B+tgt3VlGuXtt8RYqjhOFXMNl iGuk/zclXixf4flhTX/sx/4jJujV9ym8uHsVKgQajxjENSSiHBpSQZUS4ab4H5Dgkm W0JbgBwgStl9prT9yH650rDgIIySQwOm4O47l3Gs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389696AbgAXLIr (ORCPT ); Fri, 24 Jan 2020 06:08:47 -0500 Received: from mail.kernel.org ([198.145.29.99]:44192 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389686AbgAXLIo (ORCPT ); Fri, 24 Jan 2020 06:08:44 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (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 0608F20663; Fri, 24 Jan 2020 11:08:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864123; bh=eWRkYCS1XL9YkNnhsGLKtC1fiZMMAWnLCQqSNCv2kcA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=07l+EvSt7rOxws7pgJVaQzqehROTpHPziuHqrNSk2SNsubNrwqa5O5neMerO7f5Aw z3exCf4jX1ntxdSLaVLyzYH1xxN2cdsjv2cQi4psYpMufRDldmfvdqvKZqSRzlWcV2 QUHlqnMAnaDjxvMqN9S+G0Ez9u7O98UMu5zZnEvs= 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 4.19 162/639] driver core: Do not call rpm_put_suppliers() in pm_runtime_drop_link() Date: Fri, 24 Jan 2020 10:25:32 +0100 Message-Id: <20200124093107.474491990@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Rafael J. Wysocki [ Upstream commit a1fdbfbb1da2063ba98a12eb6f1bdd07451c7145 ] Calling rpm_put_suppliers() from pm_runtime_drop_link() is excessive as it affects all suppliers of the consumer device and not just the one pointed to by the device link being dropped. Worst case it may cause the consumer device to stop working unexpectedly. Moreover, in principle it is racy with respect to runtime PM of the consumer device. To avoid these problems drop runtime PM references on the particular supplier pointed to by the link in question only and do that after the link has been dropped from the consumer device's list of links to suppliers, which is in device_link_free(). Fixes: a0504aecba76 ("PM / runtime: Drop usage count for suppliers at device link removal") Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/base/core.c | 3 +++ drivers/base/power/runtime.c | 2 -- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index 20ae18f44dcdf..7599147d5f83c 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -357,6 +357,9 @@ EXPORT_SYMBOL_GPL(device_link_add); static void device_link_free(struct device_link *link) { + while (refcount_dec_not_one(&link->rpm_active)) + pm_runtime_put(link->supplier); + put_device(link->consumer); put_device(link->supplier); kfree(link); diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c index b914932d3ca1a..ab454c4533ba1 100644 --- a/drivers/base/power/runtime.c +++ b/drivers/base/power/runtime.c @@ -1603,8 +1603,6 @@ void pm_runtime_new_link(struct device *dev) void pm_runtime_drop_link(struct device *dev) { - rpm_put_suppliers(dev); - spin_lock_irq(&dev->power.lock); WARN_ON(dev->power.links_count == 0); dev->power.links_count--; -- 2.20.1