From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753629AbaGKUdq (ORCPT ); Fri, 11 Jul 2014 16:33:46 -0400 Received: from asavdk3.altibox.net ([109.247.116.14]:48113 "EHLO asavdk3.altibox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752360AbaGKUdo (ORCPT ); Fri, 11 Jul 2014 16:33:44 -0400 Date: Fri, 11 Jul 2014 22:33:23 +0200 From: Sam Ravnborg To: Thierry Reding Cc: Greg Kroah-Hartman , Sumit Semwal , dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, Michal Marek , linux-kbuild@vger.kernel.org Subject: Re: [RFC] dma-buf: Implement test module Message-ID: <20140711203323.GA10328@ravnborg.org> References: <1386858989-1487-1-git-send-email-treding@nvidia.com> <20131212144210.GA1527@ulmo.nvidia.com> <20131213020258.GC13333@kroah.com> <20140325161722.GA23842@ulmo> <20140325180110.GA3532@ravnborg.org> <20140326083247.GA9512@ulmo> <20140710095524.GB21583@ulmo> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140710095524.GB21583@ulmo> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jul 10, 2014 at 11:55:26AM +0200, Thierry Reding wrote: > On Wed, Mar 26, 2014 at 09:32:47AM +0100, Thierry Reding wrote: > > On Tue, Mar 25, 2014 at 07:01:10PM +0100, Sam Ravnborg wrote: > > > > > > > > There are two things that don't work too well with this. First this > > > > causes the build to break if the build machine doesn't have the new > > > > public header (include/uapi/linux/dma-buf.h) installed yet. So the only > > > > way to make this work would be by building the kernel once with SAMPLES > > > > disabled, install the headers and then build again with SAMPLES enabled. > > > > Which really isn't very nice. > > > > > > > > One other option that I've tried is to modify the include path so that > > > > the test program would get the in-tree copy of the public header file, > > > > but that didn't build properly either because the header files aren't > > > > properly sanitized and therefore the compiler complains about it > > > > (include/uapi/linux/types.h). > > > > > > > > One other disadvantage of carrying the sample program in the tree is > > > > that there's only infrastructure to build programs natively on the build > > > > machine. That's somewhat unfortunate because if you want to run the test > > > > program on a different architecture you have to either compile the > > > > kernel natively on that architecture (which isn't very practical on many > > > > embedded devices) or cross-compile manually. > > > > > > > > I think a much nicer solution would be to add infrastructure to cross- > > > > compile these test programs, so that they end up being built for the > > > > same architecture as the kernel image (i.e. using CROSS_COMPILE). > > > > > > > > Adding Michal and the linux-kbuild mailing list, perhaps this has been > > > > discussed before, or maybe somebody has a better idea on how to solve > > > > this. > > > I actually looked into this some time ago. > > > May try to dust off the patch. > > > IIRC the kernel provided headers were used for building - not the one installed on the machine. > > > And crosscompile were supported. > > > > That sounds exactly like what I'd want for this. If you need any help, > > please let me know. > > Did you have any time to look into dusting off the patch? If not I'll > gladly take whatever you have and dust it off myself. Thanks for the reminder. I got it almost working after simplifying it a lot. I will be travelling for the next few days but will continue to work on this after the weekend. Sam