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=-18.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 autolearn=unavailable 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 9770FC433DB for ; Mon, 8 Feb 2021 10:15:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4D12D64E76 for ; Mon, 8 Feb 2021 10:15:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232146AbhBHKOu (ORCPT ); Mon, 8 Feb 2021 05:14:50 -0500 Received: from mail.kernel.org ([198.145.29.99]:33188 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232355AbhBHKIM (ORCPT ); Mon, 8 Feb 2021 05:08:12 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id D37FA601FB; Mon, 8 Feb 2021 10:07:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1612778849; bh=gdHdGxSWxUqD1mP5CuSSmNhSTLa95bu1XHK1XXgsSzo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=p5b9bdRwb7RVTFzxKvI3tU/kyCYfO4I5O8txacBWdj3LW9TuRnDdx0LqAtW4wg8Oj tHFGgwevsJ+G/2pVQf5nInIMxJeHUxhVVTKB+MYgxKshfs06P9JcpLCNhiSAEjzn4C XwmrBr1VYebbSAFo5h6z5HhubfIQDLd6xYTvrOVsd6rrNa/Y9aFv4jm+0Ahcmlh5pc ow4GISiz5M71jnTz3xJB2QsumAFr+F2E54CXWx3dfcdKLSmQq7CGkCC1+xdnak9dqE PLHkJoICyheIUUSILWN2E1MBVwcgIuCCOZcc5jkwnhhYFmi8WolVlAysmZtffZLUtQ /LHWHoQXgb3EQ== Date: Mon, 8 Feb 2021 11:07:23 +0100 From: Mauro Carvalho Chehab To: Sakari Ailus Cc: Jacopo Mondi , Linux Media Mailing List , Laurent Pinchart , Jacopo Mondi , Stephen Rothwell , linux-next@vger.kernel.org Subject: Re: [PATCH] media: i2c: fix max9271 build dependencies Message-ID: <20210208110723.4859ddda@coco.lan> In-Reply-To: <20210208092424.GP32460@paasikivi.fi.intel.com> References: <20210208113208.35449879@canb.auug.org.au> <20210208065315.1914616-1-mchehab+huawei@kernel.org> <20210208072701.GI32460@paasikivi.fi.intel.com> <20210208083616.3iulzo56mhn4ymmq@uno.localdomain> <20210208084147.GN32460@paasikivi.fi.intel.com> <20210208100822.76ca0c2e@coco.lan> <20210208092424.GP32460@paasikivi.fi.intel.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org Em Mon, 8 Feb 2021 11:24:25 +0200 Sakari Ailus escreveu: > On Mon, Feb 08, 2021 at 10:08:22AM +0100, Mauro Carvalho Chehab wrote: > > Em Mon, 8 Feb 2021 10:41:47 +0200 > > Sakari Ailus escreveu: > > > > > Hi Jacopo, > > > > > > On Mon, Feb 08, 2021 at 09:36:16AM +0100, Jacopo Mondi wrote: > > > > Hello everyone, > > > > > > > > On Mon, Feb 08, 2021 at 09:27:01AM +0200, Sakari Ailus wrote: > > > > > Hi Mauro, > > > > > > > > > > Thanks for the patch. > > > > > > > > Sorry, that's cleary an oversight from my side. > > > > Thanks for tackling it. > > > > > > > > > > > > > > On Mon, Feb 08, 2021 at 07:53:15AM +0100, Mauro Carvalho Chehab wrote: > > > > > > As described on its c file, the Maxim MAX9271 GMSL serializer isn't a > > > > > > self-contained driver, as MAX9271 is usually embedded in camera modules > > > > > > with at least one image sensor and optional additional components, > > > > > > such as uController units or ISPs/DSPs. > > > > > > > > > > > > After chanseset a59f853b3b4b ("media: i2c: Add driver for RDACM21 camera module"), > > > > > > there are now two drivers currently needing it: rdacm20 and rdacm21. > > > > > > > > > > > > Building with allmodconfig is now causing those warnings: > > > > > > > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_set_serial_link' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_configure_i2c' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_set_high_threshold' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_configure_gmsl_link' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_set_gpios' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_clear_gpios' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_enable_gpios' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_disable_gpios' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_verify_id' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_set_address' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_set_deserializer_address' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > WARNING: modpost: drivers/media/i2c/rdacm21-camera_module: 'max9271_set_translation' exported twice. Previous export was in drivers/media/i2c/rdacm20-camera_module.ko > > > > > > > > > > > > Address the issue by adding a Kconfig item for it, that it is > > > > > > seleced if either one of the modules that need max9271 is used. > > > > > > > > > > > > Reported-by: Stephen Rothwell > > > > > > Fixes: a59f853b3b4b ("media: i2c: Add driver for RDACM21 camera module") > > > > > > Signed-off-by: Mauro Carvalho Chehab > > > > > > --- > > > > > > drivers/media/i2c/Kconfig | 10 ++++++++++ > > > > > > drivers/media/i2c/Makefile | 8 ++++---- > > > > > > 2 files changed, 14 insertions(+), 4 deletions(-) > > > > > > > > > > > > diff --git a/drivers/media/i2c/Kconfig b/drivers/media/i2c/Kconfig > > > > > > index 2d3dc0d82f9e..a6802195d583 100644 > > > > > > --- a/drivers/media/i2c/Kconfig > > > > > > +++ b/drivers/media/i2c/Kconfig > > > > > > @@ -712,6 +712,16 @@ config VIDEO_ST_MIPID02 > > > > > > module will be called st-mipid02. > > > > > > endmenu > > > > > > > > > > > > +# > > > > > > +# Camera ancillary chips > > > > > > +# > > > > > > + > > > > > > +# MAX9271 is usually embedded in camera modules > > > > > > +config VIDEO_MAX9271_SERIALIZER > > > > > > + tristate > > > > > > + default y > > > > > > + depends on VIDEO_RDACM20 || VIDEO_RDACM21 > > > > > > + > > > > > > > > > > I'd instead make the RDACM drivers depend on this one instead. The RDACM20 > > > > > driver directly depends on the symbols in the MAX9271 driver. > > > > While such solution is technically OK, it will make harder for the ones > > wanting to use the RDACM drivers, because those two drivers will be > > ridden at the config menu, until MAX9271 got selected. > > > > With the above solution, this driver will be auto-selected if either > > RDACM20 or RDACM21 is needed. > > > > Btw, this is exactly the same strategy we use for tuner I2C modules: > > the user doesn't need to know that his board uses tuner "foo" or "bar". > > All it needs is to know that it will require, for instance, the em28xx > > driver. > > > > > > > > > > > > > > > OTOH I it makes sense to have MAX9271 depend on the camera modules, as > > > > selecting the serializer alone is not that useful. > > > > > > > > Could the two camera modules symbols instead select the MAX9271 one ? > > > > > > MAX9271 could be used elsewhere than in RDACM* devices. > > > > Sure, but then it is just a matter of adding the other driver there: > > > > depends on VIDEO_RDACM20 || VIDEO_RDACM21 || VIDEO_FOO > > > > To be frank, I doubt that we'll end having dozens of boards with this. > > If we end having lots of drivers, we can work on a different > > solution. > > Also note that there will be combinations of something compiled as a module > and another driver linked directly to the kernel. > > So each of the RDACM drivers would likely also need: > > depends on VIDEO_MAX9271_SERIALIZER || !VIDEO_MAX9271_SERIALIZER No. I fail to see where this would work, as MAX9271 is a mandatory dependency of those drivers. See: static int rdacm20_s_stream(struct v4l2_subdev *sd, int enable) { struct rdacm20_device *dev = sd_to_rdacm20(sd); return max9271_set_serial_link(dev->serializer, enable); } Without compiling max9271, the device won't stream ;-) - Yet, assuming that this could be an optional feature, if you use this: config VIDEO_MAX9271_SERIALIZER tristate default y depends on VIDEO_RDACM20 || VIDEO_RDACM21 You should *not* never do: depends on VIDEO_MAX9271_SERIALIZER || !VIDEO_MAX9271_SERIALIZER for VIDEO_RDACM20 or VIDEO_RDACM21, as it would cause a dependency loop. - If you do, instead: if VIDEO_V4L2 && I2C config VIDEO_MAX9271_SERIALIZER tristate config VIDEO_RDACM20 select VIDEO_MAX9271_SERIALIZER ... config VIDEO_RDACM21 select VIDEO_MAX9271_SERIALIZER ... endif Then you also won't need: depends on VIDEO_MAX9271_SERIALIZER || !VIDEO_MAX9271_SERIALIZER As select should do the right thing in this case, ensuring that MAX9271 will be builtin either if RDACM20 or RDACM21 is builtin. - This should also work: config VIDEO_MAX9271_SERIALIZER tristate ... if VIDEO_MAX9271_SERIALIZER config VIDEO_RDACM20 tristate ... config VIDEO_RDACM21 tristate ... endif without needing a "depend on FOO || !FOO" logic, but, as I said before, this case will force the user that want to build the RDACM20/RDACM21 drivers to be aware that a MAX9271 driver is required. - You would only need a "depend on FOO || !FOO" if the driver FOO is optional and if you try do something like: config FOO tristate ... config VIDEO_RDACM20 tristate depends on FOO ... config VIDEO_RDACM21 tristate depends on FOO ... as, on such case, it would allow the vars to be: FOO="m" VIDEO_RDACM20="y" VIDEO_RDACM21="m" which would cause build errors. Thanks, Mauro