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=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,URIBL_BLOCKED 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 A9B09C433C1 for ; Sun, 28 Mar 2021 13:28:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7B7CF61580 for ; Sun, 28 Mar 2021 13:28:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230092AbhC1N1y (ORCPT ); Sun, 28 Mar 2021 09:27:54 -0400 Received: from bhuna.collabora.co.uk ([46.235.227.227]:33084 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229543AbhC1N1n (ORCPT ); Sun, 28 Mar 2021 09:27:43 -0400 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: ezequiel) with ESMTPSA id C27381F4645C Message-ID: Subject: Re: [PATCH v2 4/4] v4l: async, fwnode: Improve module organisation From: Ezequiel Garcia To: Sakari Ailus Cc: linux-media@vger.kernel.org, ezequiel.garcia@collabora.com Date: Sun, 28 Mar 2021 10:27:35 -0300 In-Reply-To: <20210323192742.GA3@paasikivi.fi.intel.com> References: <20210312125657.25442-1-sakari.ailus@linux.intel.com> <20210312125657.25442-5-sakari.ailus@linux.intel.com> <8f28218c90cdf22dd7f3d2cea259f4013ff263c4.camel@collabora.com> <20210323192742.GA3@paasikivi.fi.intel.com> Organization: Collabora Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.2-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On Tue, 2021-03-23 at 21:27 +0200, Sakari Ailus wrote: > Hi Ezequiel, > > On Tue, Mar 23, 2021 at 02:46:04PM -0300, Ezequiel Garcia wrote: > > On Fri, 2021-03-12 at 14:56 +0200, Sakari Ailus wrote: > > > The V4L2 async framework is generally used with the V4L2 fwnode, which > > > also depends on the former. There is only one exception, the CAFE_CCIC > > > driver, which uses V4L2 async but does not need V4L2 fwnode. > > > > > > At the same time there is a vast number of systems that need videodev > > > module, but have no use for v4l2-async that's now part of videodev. > > > > > > In order to improve, build v4l2-async and v4l2-fwnode as a single module > > > called v4l2-async (the v4l2-async.c file is renamed as v4l2-async-core.c). > > > Also the menu item V4L2_FWNODE is renamed as V4L2_ASYNC. > > > > > > > Seems this is not what this patch is doing: the symbol is not renamed, > > and now we have two modules v4l2-fwnode.ko and v4l2-async.ko, unless > > I'm confused. > > Oh, well, I changed what the patch does but forgot to update this. :-I > > Basically this now splits v4l2-async out of videodev. > > > > > I personally was more fond of having just one v4l2-async.ko module, > > but I'm not sure if you found any obstacles. > > > > > This also moves the initialisation of the debufs entries for async subdevs > > > to loading of the v4l2-async module. The directory is named as > > > "v4l2-async". > > > > > > Signed-off-by: Sakari Ailus > > > --- > > >  drivers/media/i2c/Kconfig            |  8 ++++++++ > > >  drivers/media/v4l2-core/Kconfig      |  4 ++++ > > >  drivers/media/v4l2-core/Makefile     | 11 +++++++++-- > > >  drivers/media/v4l2-core/v4l2-async.c | 23 +++++++++++++++++++++-- > > >  drivers/media/v4l2-core/v4l2-dev.c   |  5 ----- > > >  5 files changed, 42 insertions(+), 9 deletions(-) > > > > > [..] > > > diff --git a/drivers/media/v4l2-core/Makefile b/drivers/media/v4l2-core/Makefile > > > index e4cd589b99a5..eb5ebb5461fd 100644 > > > --- a/drivers/media/v4l2-core/Makefile > > > +++ b/drivers/media/v4l2-core/Makefile > > > @@ -7,15 +7,22 @@ tuner-objs    :=      tuner-core.o > > >   > > >  videodev-objs  :=      v4l2-dev.o v4l2-ioctl.o v4l2-device.o v4l2-fh.o \ > > >                         v4l2-event.o v4l2-ctrls.o v4l2-subdev.o \ > > > -                       v4l2-async.o v4l2-common.o > > > +                       v4l2-common.o > > >  videodev-$(CONFIG_COMPAT) += v4l2-compat-ioctl32.o > > >  videodev-$(CONFIG_TRACEPOINTS) += v4l2-trace.o > > >  videodev-$(CONFIG_MEDIA_CONTROLLER) += v4l2-mc.o > > >  videodev-$(CONFIG_SPI) += v4l2-spi.o > > >  videodev-$(CONFIG_VIDEO_V4L2_I2C) += v4l2-i2c.o > > >   > > > -obj-$(CONFIG_V4L2_FWNODE) += v4l2-fwnode.o > > >  obj-$(CONFIG_VIDEO_V4L2) += videodev.o > > > +ifneq ($(findstring y,$(CONFIG_V4L2_ASYNC)$(CONFIG_V4L2_FWNODE)),) > > > > Hm, to me this ifdefery is an indication that we are trying > > to do something fishy. > > What's happening here is that v4l2-fwnode depends on v4l2-async, but for > drivers to avoid selecting both, v4l2-async is built if only > CONFIG_V4L2_FWNODE is set. > > So this perhaps isn't too pretty but it saves hassle in Kconfig files. > How about: v4l2-async-objs := v4l2-async-core.o v4l2-async-$(CONFIG_V4L2_FWNODE) += v4l2-fwnode.o obj-$(CONFIG_V4L2_ASYNC) += v4l2-async.o config V4L2_FWNODE bool select V4L2_ASYNC config V4L2_ASYNC tristate This avoids the ifdefs and expresses the same behavior you stated above: * v4l2-async is now out of videodev * v4l2-fwnode depends on v4l2-async (through select in this case, given they are helper modules). * v4l2-async is built if CONFIG_V4L2_FWNODE is set. And v4l2-async is a module or built-in, depending on the media subsystem (MEDIA_SUPPORT) being module or built-in, which I think makes sense. Thanks, Ezequiel