From patchwork Wed Jul 7 17:29:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Adrian Hunter X-Patchwork-Id: 471068 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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 63055C07E95 for ; Wed, 7 Jul 2021 17:29:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B99961CC7 for ; Wed, 7 Jul 2021 17:29:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230148AbhGGRcS (ORCPT ); Wed, 7 Jul 2021 13:32:18 -0400 Received: from mga02.intel.com ([134.134.136.20]:29423 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229717AbhGGRcS (ORCPT ); Wed, 7 Jul 2021 13:32:18 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10037"; a="196517848" X-IronPort-AV: E=Sophos;i="5.84,220,1620716400"; d="scan'208";a="196517848" Received: from fmsmga001.fm.intel.com ([10.253.24.23]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jul 2021 10:29:37 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,220,1620716400"; d="scan'208";a="563989969" Received: from ahunter-desktop.fi.intel.com ([10.237.72.79]) by fmsmga001.fm.intel.com with ESMTP; 07 Jul 2021 10:29:33 -0700 From: Adrian Hunter To: "Rafael J . Wysocki" Cc: Greg Kroah-Hartman , Saravana Kannan , "Martin K . Petersen" , "James E . J . Bottomley" , linux-scsi@vger.kernel.org, Avri Altman , Bean Huo , Can Guo , Asutosh Das , Bart Van Assche , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RFC 0/2] driver core: Add ability to delete device links of unregistered devices Date: Wed, 7 Jul 2021 20:29:46 +0300 Message-Id: <20210707172948.1025-1-adrian.hunter@intel.com> X-Mailer: git-send-email 2.17.1 Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi There is an issue with the SCSI UFS driver when the optional BOOT well-known LUN fails to probe, which is not a fatal error. The issue is that the device and its "managed" device link do not then get deleted. The device because the device link has a reference to it. The device link because it can only be deleted by device_del(), but device_add() was never called, so device_del() never will be either. It is not clear if there is a way to get rid of the device link in this case, so here is a patch to add a function that does just that. There is also a patch to use the new function to fix the issue with the SCSI UFS driver. Adrian Hunter (2): driver core: Add ability to delete device links of unregistered devices scsi: ufshcd: Fix device links when BOOT WLUN fails to probe Documentation/driver-api/device_link.rst | 7 +++++-- drivers/base/core.c | 22 +++++++++++++++++++--- drivers/scsi/ufs/ufshcd.c | 7 +++++++ include/linux/device.h | 1 + 4 files changed, 32 insertions(+), 5 deletions(-) Regards Adrian