From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751390Ab1HXNZe (ORCPT ); Wed, 24 Aug 2011 09:25:34 -0400 Received: from perceval.ideasonboard.com ([95.142.166.194]:40055 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750733Ab1HXNZd (ORCPT ); Wed, 24 Aug 2011 09:25:33 -0400 From: Laurent Pinchart To: "Hiremath, Vaibhav" Subject: Re: [PATCHv2] ISP:BUILD:FIX: Move media_entity_init() and Date: Wed, 24 Aug 2011 15:25:46 +0200 User-Agent: KMail/1.13.7 (Linux/2.6.37-gentoo-r3; KDE/4.6.5; x86_64; ; ) Cc: "Ravi, Deepthy" , "mchehab@infradead.org" , "linux-media@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-omap@vger.kernel.org" References: <1313761725-6614-1-git-send-email-deepthy.ravi@ti.com> <201108241329.48147.laurent.pinchart@ideasonboard.com> <19F8576C6E063C45BE387C64729E739404EC007BE3@dbde02.ent.ti.com> In-Reply-To: <19F8576C6E063C45BE387C64729E739404EC007BE3@dbde02.ent.ti.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201108241525.47332.laurent.pinchart@ideasonboard.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Vaibhav, On Wednesday 24 August 2011 14:19:01 Hiremath, Vaibhav wrote: > On Wednesday, August 24, 2011 5:00 PM Laurent Pinchart wrote: > > On Wednesday 24 August 2011 13:21:27 Ravi, Deepthy wrote: > > > On Wed, Aug 24, 2011 at 4:47 PM, Laurent Pinchart wrote: > > > > On Friday 19 August 2011 15:48:45 Deepthy Ravi wrote: > > > >> From: Vaibhav Hiremath > > > >> > > > >> Fix the build break caused when CONFIG_MEDIA_CONTROLLER > > > >> option is disabled and if any sensor driver has to be used > > > >> between MC and non MC framework compatible devices. > > > >> > > > >> For example,if tvp514x video decoder driver migrated to > > > >> MC framework is being built without CONFIG_MEDIA_CONTROLLER > > > >> option enabled, the following error messages will result. > > > >> drivers/built-in.o: In function `tvp514x_remove': > > > >> drivers/media/video/tvp514x.c:1285: undefined reference to > > > >> `media_entity_cleanup' > > > >> drivers/built-in.o: In function `tvp514x_probe': > > > >> drivers/media/video/tvp514x.c:1237: undefined reference to > > > >> `media_entity_init' > > > > > > > > If the tvp514x is migrated to the MC framework, its Kconfig option > > > > should depend on MEDIA_CONTROLLER. > > > > > > The same TVP514x driver is being used for both MC and non MC compatible > > > devices, for example OMAP3 and AM35x. So if it is made dependent on > > > MEDIA CONTROLLER, we cannot enable the driver for MC independent > > > devices. > > > > Then you should use conditional compilation in the tvp514x driver itself. > > Or > > No. I am not in favor of conditional compilation in driver code. Actually, thinking some more about this, you should make the tvp514x driver depend on CONFIG_MEDIA_CONTROLLER unconditionally. This doesn't mean that the driver will become unusable by applications that are not MC-aware. Hosts/bridges don't have to export subdev nodes, they can just call subdev pad-level operations internally and let applications control the whole device through a single V4L2 video node. > > better, port the AM35x driver to the MC API. > > Why should we use MC if I have very simple device (like AM35x) which only > supports single path? I can very well use simple V4L2 sub-dev based > approach (master - slave), isn't it? The AM35x driver should use the in-kernel MC and V4L2 subdev APIs, but it doesn't have to expose them to userspace. -- Regards, Laurent Pinchart