From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id 9C7CDDDE06 for ; Sat, 25 Oct 2008 10:56:16 +1100 (EST) Message-Id: <15DE97BA-2254-4553-BEF2-C92D0C18B9DD@kernel.crashing.org> From: Kumar Gala To: Nate Case In-Reply-To: <1224892277.30047.64.camel@localhost.localdomain> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Mime-Version: 1.0 (Apple Message framework v929.2) Subject: Re: [PATCH] powerpc: enforce a non-spe kernel build even on broken compilers Date: Fri, 24 Oct 2008 18:55:56 -0500 References: <20080901142302.GA13754@www.tglx.de> <76A823BD-A9B8-4FB4-B09B-F818687193CA@kernel.crashing.org> <20081014224946.GA2503@www.tglx.de> <20081015085904.GA28369@Chamillionaire.breakpoint.cc> <6115D7FB-7500-4F67-B02B-B64B92B33D1A@kernel.crashing.org> <20081015144359.GA30649@Chamillionaire.breakpoint.cc> <1224252131.7879.117.camel@localhost.localdomain> <1224892277.30047.64.camel@localhost.localdomain> Cc: linuxppc-dev@ozlabs.org, Sebastian Andrzej Siewior , ths@linutronix.de List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Oct 24, 2008, at 6:51 PM, Nate Case wrote: > On Fri, 2008-10-17 at 09:02 -0500, Nate Case wrote: >>> With this patch it compiles and boots fine. >>> The option -mabi=no-spe is not required. >> >> Please don't accept this patch yet. My past testing showed that >> "-mabi=no-spe" was required for my toolchain. I'll go back and >> double >> check though. > > OK, I went back and re-tested. > > Kernel: 2.6.27 > CPU: MPC8572 > Toolchain: > Cross-compiler built using crosstool-ng > gcc 4.3.1, default target CFLAGS include '-mabi=spe -mspe' > binutils 2.18.90 snapshot (built with --enable-spe=yes) > > Kbuild flags Result > ------------ ------ > -mno-spe (*) FAILED > -mno-spe -mabi=no-spe FAILED > -mno-spe -mspe=no OK > -mspe=no OK > > (*) 2.6.27 default > > In the failure case, the kernel would repeatedly dump out "SPE used in > kernel (task=xxxxxxxx, pc=xxxxxxxx)". > > I think I was fooled before because I added _both_ "-mspe=no" and > "-mabi=no-spe" to my KBUILD_CFLAGS and saw the problem go away. > Since I > trusted the documentation that -mspe=no and -mno-spe were the same, I > assumed that -mabi=no-spe was the key. > > So, I've changed my mind. I now agree with Sebastian that > "-mabi=no-spe" is not required. "-mno-spe -mspe=no" is probably the > safe way to go. > > -- > Nate Case thanks for testing this all out. I'll submit a patch to remove the -mabi=.*spe.* foo. - k