From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from osg.samsung.com ([64.30.133.232]:34121 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750937AbeAYKl7 (ORCPT ); Thu, 25 Jan 2018 05:41:59 -0500 Date: Thu, 25 Jan 2018 08:41:44 -0200 From: Mauro Carvalho Chehab To: Niklas =?UTF-8?B?U8O2ZGVybHVuZA==?= Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: Re: [PATCH] v4l2-dev.h: fix symbol collision in media_entity_to_video_device() Message-ID: <20180125084116.6eec66e0@vela.lan> In-Reply-To: <20180125003430.18558-1-niklas.soderlund+renesas@ragnatech.se> References: <20180125003430.18558-1-niklas.soderlund+renesas@ragnatech.se> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-renesas-soc-owner@vger.kernel.org List-ID: Hi Niklas, Em Thu, 25 Jan 2018 01:34:30 +0100 Niklas Söderlund escreveu: > A recent change to the media_entity_to_video_device() macro breaks some > use-cases for the macro due to a symbol collision. Before the change > this worked: > > vdev = media_entity_to_video_device(link->sink->entity); > > While after the change it results in a compiler error "error: 'struct > video_device' has no member named 'link'; did you mean 'lock'?". While > the following still works after the change. > > struct media_entity *entity = link->sink->entity; > vdev = media_entity_to_video_device(entity); > > Fix the collision by renaming the macro argument to 'media_entity'. > > Signed-off-by: Niklas Söderlund > --- > include/media/v4l2-dev.h | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > Hi Mauro, > > As the offending commit is not yet upstream and I'm not sure if the > commit ids in the media-tree are stable. If they are please attach the > following fixes tag. They are. > > Fixes: 69b925c5fc36d8f1 ("media: v4l2-dev.h: add kernel-doc to two macros") > > Regards, > // Niklas > > diff --git a/include/media/v4l2-dev.h b/include/media/v4l2-dev.h > index 267fd2bed17bd3c1..f0fc1ebda47244b3 100644 > --- a/include/media/v4l2-dev.h > +++ b/include/media/v4l2-dev.h > @@ -298,10 +298,10 @@ struct video_device > * media_entity_to_video_device - Returns a &struct video_device from > * the &struct media_entity embedded on it. > * > - * @entity: pointer to &struct media_entity > + * @media_entity: pointer to &struct media_entity > */ > -#define media_entity_to_video_device(entity) \ > - container_of(entity, struct video_device, entity) > +#define media_entity_to_video_device(media_entity) \ > + container_of(media_entity, struct video_device, entity) Instead, the best would be to use __entity (or __media_entity). That would very likely prevent future conflicts. > > /** > * to_video_device - Returns a &struct video_device from the Cheers, Mauro