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=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 19E1DC43331 for ; Thu, 2 Apr 2020 13:20:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E0714206F5 for ; Thu, 2 Apr 2020 13:20:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388570AbgDBNUK (ORCPT ); Thu, 2 Apr 2020 09:20:10 -0400 Received: from foss.arm.com ([217.140.110.172]:42702 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729166AbgDBNUK (ORCPT ); Thu, 2 Apr 2020 09:20:10 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id E3B2630E; Thu, 2 Apr 2020 06:20:09 -0700 (PDT) Received: from [10.57.59.199] (unknown [10.57.59.199]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B33B83F52E; Thu, 2 Apr 2020 06:20:08 -0700 (PDT) Subject: Re: How to fix WARN from drivers/base/dd.c in next-20200401 if CONFIG_MODULES=y? To: Yoshihiro Shimoda , "john.stultz@linaro.org" Cc: "gregkh@linuxfoundation.org" , "iommu@lists.linux-foundation.org" , LKML , "rafael@kernel.org" References: From: Robin Murphy Message-ID: Date: Thu, 2 Apr 2020 14:20:03 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020-04-02 11:16 am, Yoshihiro Shimoda wrote: > Hi John, > > I found an issue after applied the following patches: > --- > 64c775f driver core: Rename deferred_probe_timeout and make it global > 0e9f8d0 driver core: Remove driver_deferred_probe_check_state_continue() > bec6c0e pinctrl: Remove use of driver_deferred_probe_check_state_continue() > e2cec7d driver core: Set deferred_probe_timeout to a longer default if CONFIG_MODULES is set > c8c43ce driver core: Fix driver_deferred_probe_check_state() logic > --- > > Before these patches, on my environment [1], some device drivers > which has iommus property output the following message when probing: > > [ 3.222205] ravb e6800000.ethernet: ignoring dependency for device, assuming no driver > [ 3.257174] ravb e6800000.ethernet eth0: Base address at 0xe6800000, 2e:09:0a:02:eb:2d, IRQ 117. > > So, since ravb driver is probed within 4 seconds, we can use NFS rootfs correctly. > > However, after these patches are applied, since the patches are always waiting for 30 seconds > for of_iommu_configure() when IOMMU hardware is disabled, drivers/base/dd.c output WARN. > Also, since ravb cannot be probed for 30 seconds, we cannot use NFS rootfs anymore. > JFYI, I copied the kernel log to the end of this email. > > I guess the patches will be merged into v5.7-rc1 because the patches are contained from > next-20200316, I'd like to fix the issue in v5.7-rcN cycle somehow. This already came up in a different context, and there's a proposal from John here: https://lore.kernel.org/lkml/20200330202715.86609-1-john.stultz@linaro.org/ Robin.