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 9A111FA372C for ; Fri, 8 Nov 2019 16:44:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 79D67206DF for ; Fri, 8 Nov 2019 16:44:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727390AbfKHQoa (ORCPT ); Fri, 8 Nov 2019 11:44:30 -0500 Received: from lhrrgout.huawei.com ([185.176.76.210]:2078 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727149AbfKHQo3 (ORCPT ); Fri, 8 Nov 2019 11:44:29 -0500 Received: from LHREML713-CAH.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id 41E724EA76087BF488D6; Fri, 8 Nov 2019 16:44:27 +0000 (GMT) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by LHREML713-CAH.china.huawei.com (10.201.108.36) with Microsoft SMTP Server (TLS) id 14.3.408.0; Fri, 8 Nov 2019 16:44:26 +0000 Received: from [127.0.0.1] (10.202.226.46) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.1713.5; Fri, 8 Nov 2019 16:44:26 +0000 Subject: Re: [PATCH v2 6/9] Revert "iommu/arm-smmu: Make arm-smmu-v3 explicitly non-modular" From: John Garry To: Will Deacon , , CC: "Isaac J. Manjarres" , Jean-Philippe Brucker , Saravana Kannan , "Bjorn Helgaas" , Robin Murphy References: <20191108151608.20932-1-will@kernel.org> <20191108151608.20932-7-will@kernel.org> <06dfd385-1af0-3106-4cc5-6a5b8e864759@huawei.com> Message-ID: <7e906ed1-ab85-7e25-9b29-5497e98da8d8@huawei.com> Date: Fri, 8 Nov 2019 16:44:25 +0000 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <06dfd385-1af0-3106-4cc5-6a5b8e864759@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.202.226.46] X-ClientProxiedBy: lhreml703-chm.china.huawei.com (10.201.108.52) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/11/2019 16:17, John Garry wrote: > On 08/11/2019 15:16, Will Deacon wrote: >> +MODULE_DEVICE_TABLE(of, arm_smmu_of_match); > > Hi Will, > >>   static struct platform_driver arm_smmu_driver = { >>       .driver    = { >>           .name        = "arm-smmu-v3", >>           .of_match_table    = of_match_ptr(arm_smmu_of_match), >> -        .suppress_bind_attrs = true, > > Does this mean that we can now manually unbind this driver from the SMMU > device? > > Seems dangerous. Here's what happens for me: > > root@ubuntu:/sys# cd ./bus/platform/drivers/arm-smmu-v3 > ind @ubuntu:/sys/bus/platform/drivers/arm-smmu-v3# echo > arm-smmu-v3.0.auto > unbind > [   77.580351] hisi_sas_v2_hw HISI0162:01: CQE_AXI_W_ERR (0x800) found! > ho [   78.635473] platform arm-smmu-v3.0.auto: CMD_SYNC timeout at > 0x00000146 [hwprod 0x00000146, hwcons 0x00000000] > >>       }, >>       .probe    = arm_smmu_device_probe, >> +    .remove    = arm_smmu_device_remove, >>       .shutdown = arm_smmu_device_shutdown, >>   }; >> -builtin_platform_driver(arm_smmu_driver); >> +module_platform_driver(arm_smmu_driver); >> + BTW, it now looks like it was your v1 series I was testing there, on your branch iommu/module. It would be helpful to update for ease of testing. Thanks, John