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,URIBL_BLOCKED,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 534D7C04EB9 for ; Wed, 5 Dec 2018 18:10:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 04FB820892 for ; Wed, 5 Dec 2018 18:10:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 04FB820892 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=windriver.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 S1728319AbeLESKI (ORCPT ); Wed, 5 Dec 2018 13:10:08 -0500 Received: from mail1.windriver.com ([147.11.146.13]:48166 "EHLO mail1.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727257AbeLESKI (ORCPT ); Wed, 5 Dec 2018 13:10:08 -0500 Received: from ALA-HCA.corp.ad.wrs.com ([147.11.189.40]) by mail1.windriver.com (8.15.2/8.15.1) with ESMTPS id wB5I8j0b025346 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL); Wed, 5 Dec 2018 10:08:45 -0800 (PST) Received: from yow-pgortmak-d1.corp.ad.wrs.com (128.224.56.57) by ALA-HCA.corp.ad.wrs.com (147.11.189.40) with Microsoft SMTP Server id 14.3.408.0; Wed, 5 Dec 2018 10:08:44 -0800 Received: by yow-pgortmak-d1.corp.ad.wrs.com (Postfix, from userid 1000) id B377C2E0930; Wed, 5 Dec 2018 13:08:43 -0500 (EST) Date: Wed, 5 Dec 2018 13:08:43 -0500 From: Paul Gortmaker To: Steve Twiss 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 , Venu Byravarasu , "linux-omap@vger.kernel.org" , "patches@opensource.cirrus.com" , Support Opensource Subject: Re: [PATCH v2 00/22] mfd: demodularization of non-modular drivers Message-ID: <20181205180843.GD23156@windriver.com> References: <1543811009-15112-1-git-send-email-paul.gortmaker@windriver.com> <6ED8E3B22081A4459DAC7699F3695FB7021C509AD4@SW-EX-MBX02.diasemi.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <6ED8E3B22081A4459DAC7699F3695FB7021C509AD4@SW-EX-MBX02.diasemi.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [RE: [PATCH v2 00/22] mfd: demodularization of non-modular drivers] On 05/12/2018 (Wed 12:01) Steve Twiss wrote: > Hi Paul, > > On 03 December 2018 04:23, Paul Gortmaker wrote: > > > Subject: [PATCH v2 00/22] mfd: demodularization of non-modular drivers > > > > [v1 --> v2: add some more commits as requested by Lee (MFD maintainer), > > update the 00/NN text; re-do build and link testing on new linux-next. ] > > > > This group of MFD drivers are all controlled by "bool" Kconfig settings, > > but contain various amounts of largely pointless uses of infrastructure > > related to modular operations, even though they can't be built modular. > > > > We can easily remove/replace all of it. We are trying to make driver > > code consistent with the Makefiles/Kconfigs that control them. > > For the DA9052 and DA9055, changes: > > - drivers/mfd/da9052-core.c | 11 ----------- > - drivers/mfd/da9052-i2c.c | 22 ++------------------- > - drivers/mfd/da9052-irq.c | 1 - > - drivers/mfd/da9052-spi.c | 22 ++------------------- > - drivers/mfd/da9055-core.c | 13 ++----------- > - drivers/mfd/da9055-i2c.c | 24 ++--------------------- > > The responsibility can fall back to Dialog for these changes. We will > submit Kconfig patches for these and make them explicitly non-modular. > This will remove the ambiguity caused by the Kconfig bool options. [typo noted: non-modular ---> modular] Great, I'll look forward to seeing those patches to convert these drivers to modular in the near future, and I'll not re-send mine. Thanks, P. -- > > Regards, > Steve > > > This > > means not using modular functions/macros for drivers that can never be > > built as a module. Some of the downfalls this oversight leads to are: > > > > (1) it is easy to accidentally write unused module_exit and remove code > > (2) it can be misleading when reading the source, thinking it can be > > modular when the Makefile and/or Kconfig prohibit it > > (3) it requires the include of the module.h header file which in turn > > includes nearly everything else, thus adding a lot of CPP overhead. > > (4) it gets copied/replicated into other drivers and spreads quickly. > > > > What we see in current drivers falls into one or more of the following > > categories: > > > > 1) include of when it simply isn't needed > > > > 2) Use of MODULE_LICENSE, MODULE_DEVICE_TABLE, MODULE_AUTHOR etc. > > macros that are no-ops for non-modular drivers. > > > > 3) Creation of a module_exit() function that will be compiled and > > linked in but never actually called for non-modular drivers. > > > > 4) Addition of a platform_driver ".remove" function that is bound > > into the struct but will never be called for non-module use cases. > > > > Solution to #1 --> #3 is simple ; we just delete the related code. > > > > 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. > > > > Build testing was done on drivers/mfd for allyesconfig on x86_64, ARM > > and ARM-64 on a recent linux-next checkout. > > > > Paul. > > > > --- > > > > Cc: Arnd Bergmann > > Cc: Cory Maccarrone > > Cc: David Dajun Chen > > Cc: Dong Aisheng > > Cc: Eric Miao > > Cc: Graeme Gregory > > Cc: Guennadi Liakhovetski > > Cc: Haojian Zhuang > > Cc: Jin Park > > Cc: Jorge Eduardo Candelaria > > Cc: Laxman Dewangan > > Cc: Lee Jones > > Cc: Linus Walleij > > Cc: Mark Brown > > Cc: Mattias Nilsson > > Cc: Michael Hennerich > > Cc: Mike Rapoport > > Cc: Tony Lindgren > > Cc: Venu Byravarasu > > Cc: linux-omap@vger.kernel.org > > Cc: patches@opensource.cirrus.com > > Cc: Support Opensource > > > > > > Paul Gortmaker (22): > > mfd: aat2870-core: Make it explicitly non-modular > > mfd: adp5520: Make it explicitly non-modular > > mfd: as3711: Make it explicitly non-modular > > mfd: da903x: Make it explicitly non-modular > > mfd: da9052-*: Make it explicitly non-modular > > mfd: da9055-i2c: Make it explicitly non-modular > > mfd: da9055-core: make it explicitly non-modular > > mfd: db8500-prcmu: drop unused MODULE_ tags from non-modular code > > mfd: htc-i2cpld: Make it explicitly non-modular > > mfd: max8925-core: drop unused MODULE_ tags from non-modular code > > mfd: rc5t583: Make it explicitly non-modular > > mfd: sta2x11: drop unused MODULE_ tags from non-modular code > > mfd: syscon: Make it explicitly non-modular > > mfd: tps65090: Make it explicitly non-modular > > mfd: tps65910: Make it explicitly non-modular > > mfd: tps80031: Make it explicitly non-modular > > mfd: wm831x-spi: Make it explicitly non-modular > > mfd: wm831x-i2c: Make it explicitly non-modular > > mfd: wm831x-core: drop unused MODULE_ tags from non-modular code > > mfd: wm8350-i2c: Make it explicitly non-modular > > mfd: wm8350-core: drop unused MODULE_ tags from non-modular code > > mfd: wm8400-core: Make it explicitly non-modular > > > > drivers/mfd/aat2870-core.c | 40 +++------------------------------------ > > drivers/mfd/adp5520.c | 30 +++++++---------------------- > > drivers/mfd/as3711.c | 14 -------------- > > drivers/mfd/da903x.c | 26 +++---------------------- > > drivers/mfd/da9052-core.c | 11 ----------- > > drivers/mfd/da9052-i2c.c | 22 ++------------------- > > drivers/mfd/da9052-irq.c | 1 - > > drivers/mfd/da9052-spi.c | 22 ++------------------- > > drivers/mfd/da9055-core.c | 13 ++----------- > > drivers/mfd/da9055-i2c.c | 24 ++--------------------- > > drivers/mfd/db8500-prcmu.c | 10 ++++------ > > drivers/mfd/htc-i2cpld.c | 18 +----------------- > > drivers/mfd/max8925-core.c | 7 +------ > > drivers/mfd/rc5t583.c | 14 -------------- > > drivers/mfd/sta2x11-mfd.c | 10 ++++------ > > drivers/mfd/syscon.c | 12 +----------- > > drivers/mfd/tps65090.c | 30 +++++------------------------ > > drivers/mfd/tps65910.c | 18 +----------------- > > drivers/mfd/tps80031.c | 37 ++---------------------------------- > > drivers/mfd/wm831x-core.c | 7 ++----- > > drivers/mfd/wm831x-i2c.c | 20 ++------------------ > > drivers/mfd/wm831x-spi.c | 24 ++--------------------- > > drivers/mfd/wm8350-core.c | 6 ++---- > > drivers/mfd/wm8350-i2c.c | 24 +---------------------- > > drivers/mfd/wm8400-core.c | 18 +++--------------- > > include/linux/mfd/da9052/da9052.h | 1 - > > 26 files changed, 52 insertions(+), 407 deletions(-) > > > > -- > > 2.7.4 > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paul Gortmaker Subject: Re: [PATCH v2 00/22] mfd: demodularization of non-modular drivers Date: Wed, 5 Dec 2018 13:08:43 -0500 Message-ID: <20181205180843.GD23156@windriver.com> References: <1543811009-15112-1-git-send-email-paul.gortmaker@windriver.com> <6ED8E3B22081A4459DAC7699F3695FB7021C509AD4@SW-EX-MBX02.diasemi.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Return-path: Content-Disposition: inline In-Reply-To: <6ED8E3B22081A4459DAC7699F3695FB7021C509AD4@SW-EX-MBX02.diasemi.com> Sender: linux-kernel-owner@vger.kernel.org To: Steve Twiss 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 List-Id: linux-omap@vger.kernel.org [RE: [PATCH v2 00/22] mfd: demodularization of non-modular drivers] On 05/12/2018 (Wed 12:01) Steve Twiss wrote: > Hi Paul, > > On 03 December 2018 04:23, Paul Gortmaker wrote: > > > Subject: [PATCH v2 00/22] mfd: demodularization of non-modular drivers > > > > [v1 --> v2: add some more commits as requested by Lee (MFD maintainer), > > update the 00/NN text; re-do build and link testing on new linux-next. ] > > > > This group of MFD drivers are all controlled by "bool" Kconfig settings, > > but contain various amounts of largely pointless uses of infrastructure > > related to modular operations, even though they can't be built modular. > > > > We can easily remove/replace all of it. We are trying to make driver > > code consistent with the Makefiles/Kconfigs that control them. > > For the DA9052 and DA9055, changes: > > - drivers/mfd/da9052-core.c | 11 ----------- > - drivers/mfd/da9052-i2c.c | 22 ++------------------- > - drivers/mfd/da9052-irq.c | 1 - > - drivers/mfd/da9052-spi.c | 22 ++------------------- > - drivers/mfd/da9055-core.c | 13 ++----------- > - drivers/mfd/da9055-i2c.c | 24 ++--------------------- > > The responsibility can fall back to Dialog for these changes. We will > submit Kconfig patches for these and make them explicitly non-modular. > This will remove the ambiguity caused by the Kconfig bool options. [typo noted: non-modular ---> modular] Great, I'll look forward to seeing those patches to convert these drivers to modular in the near future, and I'll not re-send mine. Thanks, P. -- > > Regards, > Steve > > > This > > means not using modular functions/macros for drivers that can never be > > built as a module. Some of the downfalls this oversight leads to are: > > > > (1) it is easy to accidentally write unused module_exit and remove code > > (2) it can be misleading when reading the source, thinking it can be > > modular when the Makefile and/or Kconfig prohibit it > > (3) it requires the include of the module.h header file which in turn > > includes nearly everything else, thus adding a lot of CPP overhead. > > (4) it gets copied/replicated into other drivers and spreads quickly. > > > > What we see in current drivers falls into one or more of the following > > categories: > > > > 1) include of when it simply isn't needed > > > > 2) Use of MODULE_LICENSE, MODULE_DEVICE_TABLE, MODULE_AUTHOR etc. > > macros that are no-ops for non-modular drivers. > > > > 3) Creation of a module_exit() function that will be compiled and > > linked in but never actually called for non-modular drivers. > > > > 4) Addition of a platform_driver ".remove" function that is bound > > into the struct but will never be called for non-module use cases. > > > > Solution to #1 --> #3 is simple ; we just delete the related code. > > > > 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. > > > > Build testing was done on drivers/mfd for allyesconfig on x86_64, ARM > > and ARM-64 on a recent linux-next checkout. > > > > Paul. > > > > --- > > > > Cc: Arnd Bergmann > > Cc: Cory Maccarrone > > Cc: David Dajun Chen > > Cc: Dong Aisheng > > Cc: Eric Miao > > Cc: Graeme Gregory > > Cc: Guennadi Liakhovetski > > Cc: Haojian Zhuang > > Cc: Jin Park > > Cc: Jorge Eduardo Candelaria > > Cc: Laxman Dewangan > > Cc: Lee Jones > > Cc: Linus Walleij > > Cc: Mark Brown > > Cc: Mattias Nilsson > > Cc: Michael Hennerich > > Cc: Mike Rapoport > > Cc: Tony Lindgren > > Cc: Venu Byravarasu > > Cc: linux-omap@vger.kernel.org > > Cc: patches@opensource.cirrus.com > > Cc: Support Opensource > > > > > > Paul Gortmaker (22): > > mfd: aat2870-core: Make it explicitly non-modular > > mfd: adp5520: Make it explicitly non-modular > > mfd: as3711: Make it explicitly non-modular > > mfd: da903x: Make it explicitly non-modular > > mfd: da9052-*: Make it explicitly non-modular > > mfd: da9055-i2c: Make it explicitly non-modular > > mfd: da9055-core: make it explicitly non-modular > > mfd: db8500-prcmu: drop unused MODULE_ tags from non-modular code > > mfd: htc-i2cpld: Make it explicitly non-modular > > mfd: max8925-core: drop unused MODULE_ tags from non-modular code > > mfd: rc5t583: Make it explicitly non-modular > > mfd: sta2x11: drop unused MODULE_ tags from non-modular code > > mfd: syscon: Make it explicitly non-modular > > mfd: tps65090: Make it explicitly non-modular > > mfd: tps65910: Make it explicitly non-modular > > mfd: tps80031: Make it explicitly non-modular > > mfd: wm831x-spi: Make it explicitly non-modular > > mfd: wm831x-i2c: Make it explicitly non-modular > > mfd: wm831x-core: drop unused MODULE_ tags from non-modular code > > mfd: wm8350-i2c: Make it explicitly non-modular > > mfd: wm8350-core: drop unused MODULE_ tags from non-modular code > > mfd: wm8400-core: Make it explicitly non-modular > > > > drivers/mfd/aat2870-core.c | 40 +++------------------------------------ > > drivers/mfd/adp5520.c | 30 +++++++---------------------- > > drivers/mfd/as3711.c | 14 -------------- > > drivers/mfd/da903x.c | 26 +++---------------------- > > drivers/mfd/da9052-core.c | 11 ----------- > > drivers/mfd/da9052-i2c.c | 22 ++------------------- > > drivers/mfd/da9052-irq.c | 1 - > > drivers/mfd/da9052-spi.c | 22 ++------------------- > > drivers/mfd/da9055-core.c | 13 ++----------- > > drivers/mfd/da9055-i2c.c | 24 ++--------------------- > > drivers/mfd/db8500-prcmu.c | 10 ++++------ > > drivers/mfd/htc-i2cpld.c | 18 +----------------- > > drivers/mfd/max8925-core.c | 7 +------ > > drivers/mfd/rc5t583.c | 14 -------------- > > drivers/mfd/sta2x11-mfd.c | 10 ++++------ > > drivers/mfd/syscon.c | 12 +----------- > > drivers/mfd/tps65090.c | 30 +++++------------------------ > > drivers/mfd/tps65910.c | 18 +----------------- > > drivers/mfd/tps80031.c | 37 ++---------------------------------- > > drivers/mfd/wm831x-core.c | 7 ++----- > > drivers/mfd/wm831x-i2c.c | 20 ++------------------ > > drivers/mfd/wm831x-spi.c | 24 ++--------------------- > > drivers/mfd/wm8350-core.c | 6 ++---- > > drivers/mfd/wm8350-i2c.c | 24 +---------------------- > > drivers/mfd/wm8400-core.c | 18 +++--------------- > > include/linux/mfd/da9052/da9052.h | 1 - > > 26 files changed, 52 insertions(+), 407 deletions(-) > > > > -- > > 2.7.4 >