From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760805AbXKAO4M (ORCPT ); Thu, 1 Nov 2007 10:56:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754803AbXKAOz7 (ORCPT ); Thu, 1 Nov 2007 10:55:59 -0400 Received: from agminet01.oracle.com ([141.146.126.228]:59238 "EHLO agminet01.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754733AbXKAOz6 (ORCPT ); Thu, 1 Nov 2007 10:55:58 -0400 Message-ID: <4729E85D.4040505@oracle.com> Date: Thu, 01 Nov 2007 07:53:17 -0700 From: Randy Dunlap User-Agent: Thunderbird 1.5.0.5 (X11/20060719) MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: Trent Piepho , v4l-dvb-maintainer@linuxtv.org, lkml Subject: Re: [v4l-dvb-maintainer] bttv build error (CONFIG_NET=n) References: <20071030221508.3139ea5c.randy.dunlap@oracle.com> <20071031092350.91eae067.randy.dunlap@oracle.com> <1193905709.8587.24.camel@gaivota> In-Reply-To: <1193905709.8587.24.camel@gaivota> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAQAAAAI= X-Brightmail-Tracker: AAAAAQAAAAI= X-Whitelist: TRUE X-Whitelist: TRUE Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Mauro Carvalho Chehab wrote: > Randy, > >>> The only reason the net stuff works, is because CONFIG_NET includes igmp.c, >>> which can't be compiled as a module. That means ip_compute_csum() will get >>> pulled out of the lib.a file for igmp, and thus be present for the net modules >>> that use it too. If igmp could be turned off, made a module, or stopped using >>> ip_compute_csum(), then the users of ip_compute_csum() that do depend on >>> CONFIG_NET would have the same problem as bttv does. >> Thanks for the analysis and summary. >> (I'm still waiting for those lkml.org links to load... timed out) >> >>> It seems a shame to create a new ip checksum function in the bttv driver when >>> a perfectly good one already exists and will already be present in just about >>> every kernel out there. Honestly, how common is NET=n and VIDEO_BT848=m >>> outside of randconfig? > > This might happen on embedded devices, like a set top box or a PVR, > using a bttv hardware. > >> so just adding "depends on NET" should be OK then? > > Seems very weird to have bttv module dependent on NET, just because a > checksum calculus function is defined there. Oh, I agree with that. My comment above possibly needed a smiley. > One possible solution would be to move this function to another place > and having both NET, BTTV and other places selecting it. I gave 3 possible solutions in the beginning email. I would probably just modify bttv to support osprey only when CONFIG_NET=y. or fix the linking problem that Trent pointed out. -- ~Randy