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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 12E35C433ED for ; Mon, 20 Jul 2020 16:42:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DAA45206E9 for ; Mon, 20 Jul 2020 16:42:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595263374; bh=v5pzLyl2SJd1PntkNmxFPTeULXZvmlFGi3ShJso8gxc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=sV8wFvruiTc+W6+5ekNpo38ZvKXPsfe0vtrKUi9l0asCcBmEnyKeL5IkEAg/8DyKj X5FL/NYQwv0LdIUZs+xSIvlhIjAPiB9SFn+WRXYhZoUOgi7YuSUIbrP4nzCIa4rQ8W oW4KM6ybS7RwwlQ7RQXZVk98UrVoL+8YFQX5oqPU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730155AbgGTPm6 (ORCPT ); Mon, 20 Jul 2020 11:42:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:36034 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730143AbgGTPmy (ORCPT ); Mon, 20 Jul 2020 11:42:54 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 573EB2064B; Mon, 20 Jul 2020 15:42:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595259773; bh=v5pzLyl2SJd1PntkNmxFPTeULXZvmlFGi3ShJso8gxc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LQSvCNyB13Zq4fLSiZ0KQgdHTnq/iiqEJ1wFnPLCAyLm38cGyAh3QlpkwVA81BuKV yOiLmDB2StDU1uWOXu1UIuyx4PASgaO5vnas2+jewNcsFe3FnpX6rU/qnd2E9937XU Hz0OGUbgwnUgTSu4QB+2U6UYumaM576zN0lFl6cA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andy Whitcroft , Alexander Usyskin , Tomas Winkler Subject: [PATCH 4.9 75/86] mei: bus: dont clean driver pointer Date: Mon, 20 Jul 2020 17:37:11 +0200 Message-Id: <20200720152756.978576850@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200720152753.138974850@linuxfoundation.org> References: <20200720152753.138974850@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: Alexander Usyskin commit e852c2c251ed9c23ae6e3efebc5ec49adb504207 upstream. It's not needed to set driver to NULL in mei_cl_device_remove() which is bus_type remove() handler as this is done anyway in __device_release_driver(). Actually this is causing an endless loop in driver_detach() on ubuntu patched kernel, while removing (rmmod) the mei_hdcp module. The reason list_empty(&drv->p->klist_devices.k_list) is always not-empty. as the check is always true in __device_release_driver() if (dev->driver != drv) return; The non upstream patch is causing this behavior, titled: 'vfio -- release device lock before userspace requests' Nevertheless the fix is correct also for the upstream. Link: https://patchwork.ozlabs.org/project/ubuntu-kernel/patch/20180912085046.3401-2-apw@canonical.com/ Cc: Cc: Andy Whitcroft Signed-off-by: Alexander Usyskin Signed-off-by: Tomas Winkler Link: https://lore.kernel.org/r/20200628225359.2185929-1-tomas.winkler@intel.com Signed-off-by: Greg Kroah-Hartman --- drivers/misc/mei/bus.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/misc/mei/bus.c +++ b/drivers/misc/mei/bus.c @@ -639,9 +639,8 @@ static int mei_cl_device_remove(struct d ret = cldrv->remove(cldev); module_put(THIS_MODULE); - dev->driver = NULL; - return ret; + return ret; } static ssize_t name_show(struct device *dev, struct device_attribute *a,