From mboxrd@z Thu Jan 1 00:00:00 1970 From: Charles Keepax Subject: Re: [PATCH v2 00/22] mfd: demodularization of non-modular drivers Date: Wed, 5 Dec 2018 11:35:35 +0000 Message-ID: <20181205113535.GX16508@imbe.wolfsonmicro.main> References: <1543811009-15112-1-git-send-email-paul.gortmaker@windriver.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <1543811009-15112-1-git-send-email-paul.gortmaker@windriver.com> Sender: linux-kernel-owner@vger.kernel.org To: Paul Gortmaker Cc: Lee Jones , linux-kernel@vger.kernel.org, Arnd Bergmann , Cory Maccarrone , David Dajun Chen , Dong Aisheng , Eric Miao , Graeme Gregory , Guennadi Liakhovetski , Haojian Zhuang , Jin Park , Jorge Eduardo Candelaria , Laxman Dewangan , Linus Walleij , Mark Brown , Mattias Nilsson , Michael Hennerich , Mike Rapoport , Tony Lindgren List-Id: linux-omap@vger.kernel.org On Sun, Dec 02, 2018 at 11:23:07PM -0500, Paul Gortmaker wrote: > The solution to #4 is similar - we delete the ".remove" function and > the binding into the platform_driver struct. However, since the same > ".remove" function could also be triggered by an "unbind" (such as for > pass-through of a device to a guest instance) - so we also explicitly > disable any unbind for the driver. > > The unbind mask allows us to ensure we will see if there was some odd > corner case out there that was relying on it. Typically it would be a > multi-port ethernet card passing a port through to a guest, so a > sensible use case in MFD drivers seems highly unlikely. This same > solution has already been used in multiple other mainline subsystems. > I guess if this is a general direction thing, but it does seem that module unload is not the only reason one might ever unbind a driver. So are we sure we want to remove the option to unbind these drivers? Certainly for testing it is sometimes useful. Thanks, Charles 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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 7D311C04EBF for ; Wed, 5 Dec 2018 11:36:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 47DF320989 for ; Wed, 5 Dec 2018 11:36:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 47DF320989 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=opensource.cirrus.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727601AbeLELgn (ORCPT ); Wed, 5 Dec 2018 06:36:43 -0500 Received: from mx0a-001ae601.pphosted.com ([67.231.149.25]:53002 "EHLO mx0b-001ae601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726918AbeLELgn (ORCPT ); Wed, 5 Dec 2018 06:36:43 -0500 Received: from pps.filterd (m0077473.ppops.net [127.0.0.1]) by mx0a-001ae601.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id wB5BTc4M029184; Wed, 5 Dec 2018 05:35:40 -0600 Authentication-Results: ppops.net; spf=none smtp.mailfrom=ckeepax@opensource.cirrus.com Received: from mail1.cirrus.com (mail1.cirrus.com [141.131.3.20]) by mx0a-001ae601.pphosted.com with ESMTP id 2p3rk7ffja-1; Wed, 05 Dec 2018 05:35:40 -0600 Received: from EX17.ad.cirrus.com (unknown [172.20.9.81]) by mail1.cirrus.com (Postfix) with ESMTP id CA16C611C8B4; Wed, 5 Dec 2018 05:35:39 -0600 (CST) Received: from imbe.wolfsonmicro.main (198.61.95.81) by EX17.ad.cirrus.com (172.20.9.81) with Microsoft SMTP Server id 14.3.408.0; Wed, 5 Dec 2018 11:35:39 +0000 Received: from imbe.wolfsonmicro.main (imbe.wolfsonmicro.main [198.61.95.81]) by imbe.wolfsonmicro.main (8.14.4/8.14.4) with ESMTP id wB5BZZ82006220; Wed, 5 Dec 2018 11:35:36 GMT Date: Wed, 5 Dec 2018 11:35:35 +0000 From: Charles Keepax To: Paul Gortmaker CC: Lee Jones , , Arnd Bergmann , Cory Maccarrone , David Dajun Chen , Dong Aisheng , Eric Miao , Graeme Gregory , Guennadi Liakhovetski , Haojian Zhuang , Jin Park , Jorge Eduardo Candelaria , Laxman Dewangan , Linus Walleij , Mark Brown , Mattias Nilsson , Michael Hennerich , Mike Rapoport , Tony Lindgren , Venu Byravarasu , , , Support Opensource Subject: Re: [PATCH v2 00/22] mfd: demodularization of non-modular drivers Message-ID: <20181205113535.GX16508@imbe.wolfsonmicro.main> References: <1543811009-15112-1-git-send-email-paul.gortmaker@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1543811009-15112-1-git-send-email-paul.gortmaker@windriver.com> User-Agent: Mutt/1.5.20 (2009-12-10) X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1011 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=966 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1812050106 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 02, 2018 at 11:23:07PM -0500, Paul Gortmaker wrote: > The solution to #4 is similar - we delete the ".remove" function and > the binding into the platform_driver struct. However, since the same > ".remove" function could also be triggered by an "unbind" (such as for > pass-through of a device to a guest instance) - so we also explicitly > disable any unbind for the driver. > > The unbind mask allows us to ensure we will see if there was some odd > corner case out there that was relying on it. Typically it would be a > multi-port ethernet card passing a port through to a guest, so a > sensible use case in MFD drivers seems highly unlikely. This same > solution has already been used in multiple other mainline subsystems. > I guess if this is a general direction thing, but it does seem that module unload is not the only reason one might ever unbind a driver. So are we sure we want to remove the option to unbind these drivers? Certainly for testing it is sometimes useful. Thanks, Charles