From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757111AbXKAI25 (ORCPT ); Thu, 1 Nov 2007 04:28:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753415AbXKAI2t (ORCPT ); Thu, 1 Nov 2007 04:28:49 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:55919 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750812AbXKAI2s (ORCPT ); Thu, 1 Nov 2007 04:28:48 -0400 Subject: Re: [v4l-dvb-maintainer] bttv build error (CONFIG_NET=n) From: Mauro Carvalho Chehab To: Randy Dunlap Cc: Trent Piepho , v4l-dvb-maintainer@linuxtv.org, lkml In-Reply-To: <20071031092350.91eae067.randy.dunlap@oracle.com> References: <20071030221508.3139ea5c.randy.dunlap@oracle.com> <20071031092350.91eae067.randy.dunlap@oracle.com> Content-Type: text/plain Date: Thu, 01 Nov 2007 06:28:29 -0200 Message-Id: <1193905709.8587.24.camel@gaivota> Mime-Version: 1.0 X-Mailer: Evolution 2.21.1-1mdv2008.1 Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. One possible solution would be to move this function to another place and having both NET, BTTV and other places selecting it. -- Cheers, Mauro