From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] Kbuild: Avoid DTB rebuilds if source files are untouched Date: Mon, 15 Apr 2013 11:12:29 -0600 Message-ID: <516C34FD.6090705@wwwdotorg.org> References: <1364973141-16354-1-git-send-email-vgupta@synopsys.com> <515BD6B8.1020607@synopsys.com> <515C5652.8070705@wwwdotorg.org> <515D0FFB.4030803@synopsys.com> <515DBA0E.6000604@wwwdotorg.org> <51642158.3070205@synopsys.com> <5167BA67.5080403@synopsys.com> <5168822C.6040303@wwwdotorg.org> <516C07AC.6070608@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from avon.wwwdotorg.org ([70.85.31.133]:45630 "EHLO avon.wwwdotorg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752729Ab3DORMd (ORCPT ); Mon, 15 Apr 2013 13:12:33 -0400 In-Reply-To: <516C07AC.6070608@synopsys.com> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Vineet Gupta Cc: "linux-arch@vger.kernel.org" , linux-kernel@vger.kernel.org, Michal Marek , Stephen Warren , Grant Likely , linux-kbuild@vger.kernel.org, Sam Ravnborg On 04/15/2013 07:59 AM, Vineet Gupta wrote: > On 04/13/2013 03:22 AM, Stephen Warren wrote: >> >> After installing the ARC toolchain (which was a bit painful to track >> down and install...) > > Sorry about that - we have a buildroot based distro about to be pushed upstream - > that would make it easier. > >> I reproduced your exact problem. I believe the >> patch below fixes it: >> >> diff --git a/arch/arc/boot/dts/Makefile b/arch/arc/boot/dts/Makefile >> index 5776835..2f2cf23 100644 >> --- a/arch/arc/boot/dts/Makefile >> +++ b/arch/arc/boot/dts/Makefile >> @@ -8,6 +8,8 @@ endif >> obj-y += $(builtindtb-y).dtb.o >> targets += $(builtindtb-y).dtb >> >> +.SECONDARY: $(obj)/$(builtindtb-y).dtb.S >> + >> dtbs: $(addprefix $(obj)/, $(builtindtb-y).dtb) >> >> clean-files := *.dtb > > Indeed it does - I fell stupid why this didn't occur to me. But given that you > have dealt with the dtb Makefile stuff alot more than I have :-) do you know why > it was not working when put in Makefile.lib because I feel a few other arches also > suffer from the same issue and would need similar fixes. Searching in Google implies that .SECONDARY doesn't work with wildcards (%.dtb.S for example), whereas .PRECIOUS does. Seems like perhaps a bug in make to me, but who knows. Perhaps that's why? > Anyhow, for the patch, I can manually add --author="you" but it'll still lack your > SOB - you OK with that or do you want to send a formal patch. Sure, you can either just say Suggested-by: for me, or apply my s-o-b below: Signed-off-by: Stephen Warren