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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 2A3A1C0044C for ; Mon, 5 Nov 2018 21:12:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E85FA2084F for ; Mon, 5 Nov 2018 21:12:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E85FA2084F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387857AbeKFGdg (ORCPT ); Tue, 6 Nov 2018 01:33:36 -0500 Received: from mga06.intel.com ([134.134.136.31]:33167 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387722AbeKFGdf (ORCPT ); Tue, 6 Nov 2018 01:33:35 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Nov 2018 13:11:59 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,469,1534834800"; d="scan'208";a="105639089" Received: from ahduyck-desk1.jf.intel.com ([10.7.198.76]) by orsmga001.jf.intel.com with ESMTP; 05 Nov 2018 13:11:59 -0800 Subject: [driver-core PATCH v5 4/9] driver core: Move async_synchronize_full call From: Alexander Duyck To: linux-kernel@vger.kernel.org, gregkh@linuxfoundation.org Cc: linux-nvdimm@lists.01.org, tj@kernel.org, akpm@linux-foundation.org, linux-pm@vger.kernel.org, jiangshanlai@gmail.com, rafael@kernel.org, len.brown@intel.com, pavel@ucw.cz, zwisler@kernel.org, dan.j.williams@intel.com, dave.jiang@intel.com, bvanassche@acm.org, alexander.h.duyck@linux.intel.com Date: Mon, 05 Nov 2018 13:11:59 -0800 Message-ID: <154145231976.29224.39638353241256116.stgit@ahduyck-desk1.jf.intel.com> In-Reply-To: <154145223352.29224.8912797012647157172.stgit@ahduyck-desk1.jf.intel.com> References: <154145223352.29224.8912797012647157172.stgit@ahduyck-desk1.jf.intel.com> User-Agent: StGit/unknown-version MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch moves the async_synchronize_full call out of __device_release_driver and into driver_detach. The idea behind this is that the async_synchronize_full call will only guarantee that any existing async operations are flushed. This doesn't do anything to guarantee that a hotplug event that may occur while we are doing the release of the driver will not be asynchronously scheduled. By moving this into the driver_detach path we can avoid potential deadlocks as we aren't holding the device lock at this point and we should not have the driver we want to flush loaded so the flush will take care of any asynchronous events the driver we are detaching might have scheduled. Signed-off-by: Alexander Duyck --- drivers/base/dd.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 76c40fe69463..e74cefeb5b69 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -975,9 +975,6 @@ static void __device_release_driver(struct device *dev, struct device *parent) drv = dev->driver; if (drv) { - if (driver_allows_async_probing(drv)) - async_synchronize_full(); - while (device_links_busy(dev)) { __device_driver_unlock(dev, parent); @@ -1087,6 +1084,9 @@ void driver_detach(struct device_driver *drv) struct device_private *dev_prv; struct device *dev; + if (driver_allows_async_probing(drv)) + async_synchronize_full(); + for (;;) { spin_lock(&drv->p->klist_devices.k_lock); if (list_empty(&drv->p->klist_devices.k_list)) {