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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 CF329C11F66 for ; Wed, 7 Jul 2021 17:49:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B65E661CC8 for ; Wed, 7 Jul 2021 17:49:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231234AbhGGRwa (ORCPT ); Wed, 7 Jul 2021 13:52:30 -0400 Received: from mga14.intel.com ([192.55.52.115]:27096 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230495AbhGGRw2 (ORCPT ); Wed, 7 Jul 2021 13:52:28 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10037"; a="209171953" X-IronPort-AV: E=Sophos;i="5.84,221,1620716400"; d="scan'208";a="209171953" Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jul 2021 10:49:48 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.84,221,1620716400"; d="scan'208";a="628099852" Received: from ahunter-desktop.fi.intel.com (HELO [10.237.72.79]) ([10.237.72.79]) by orsmga005.jf.intel.com with ESMTP; 07 Jul 2021 10:49:44 -0700 Subject: Re: [PATCH RFC 2/2] scsi: ufshcd: Fix device links when BOOT WLUN fails to probe To: Greg Kroah-Hartman Cc: "Rafael J . Wysocki" , 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 References: <20210707172948.1025-1-adrian.hunter@intel.com> <20210707172948.1025-3-adrian.hunter@intel.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki Message-ID: <66130101-b0c5-a9a3-318a-468c6f3b380f@intel.com> Date: Wed, 7 Jul 2021 20:49:58 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/07/21 8:39 pm, Greg Kroah-Hartman wrote: > On Wed, Jul 07, 2021 at 08:29:48PM +0300, Adrian Hunter wrote: >> If a LUN fails to probe (e.g. absent BOOT WLUN), the device will not have >> been registered but can still have a device link holding a reference to the >> device. The unwanted device link will prevent runtime suspend indefinitely, >> and cause some warnings if the supplier is ever deleted (e.g. by unbinding >> the UFS host controller). Fix by explicitly deleting the device link when >> SCSI destroys the SCSI device. >> >> Signed-off-by: Adrian Hunter >> --- >> drivers/scsi/ufs/ufshcd.c | 7 +++++++ >> 1 file changed, 7 insertions(+) >> >> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c >> index 708b3b62fc4d..483aa74fe2c8 100644 >> --- a/drivers/scsi/ufs/ufshcd.c >> +++ b/drivers/scsi/ufs/ufshcd.c >> @@ -5029,6 +5029,13 @@ static void ufshcd_slave_destroy(struct scsi_device *sdev) >> spin_lock_irqsave(hba->host->host_lock, flags); >> hba->sdev_ufs_device = NULL; >> spin_unlock_irqrestore(hba->host->host_lock, flags); >> + } else { >> + /* >> + * If a LUN fails to probe (e.g. absent BOOT WLUN), the device >> + * will not have been registered but can still have a device >> + * link holding a reference to the device. >> + */ >> + device_links_scrap(&sdev->sdev_gendev); > > What created that link? And why did it do that before probe happened > successfully? The same driver created the link. The documentation seems to say it is allowed to, if it is the consumer. >From Documentation/driver-api/device_link.rst Usage ===== The earliest point in time when device links can be added is after :c:func:`device_add()` has been called for the supplier and :c:func:`device_initialize()` has been called for the consumer.