From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757880AbcKCOQa (ORCPT ); Thu, 3 Nov 2016 10:16:30 -0400 Received: from foss.arm.com ([217.140.101.70]:38560 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757287AbcKCOQA (ORCPT ); Thu, 3 Nov 2016 10:16:00 -0400 Date: Thu, 3 Nov 2016 14:16:00 +0000 From: Will Deacon To: Florian Fainelli Cc: Markus Mayer , Markus Mayer , Catalin Marinas , Linux Kernel Mailing List , ARM Kernel Mailing List Subject: Re: [PATCH] arm64: errata: Check for --fix-cortex-a53-843419 and --fix-cortex-a53 Message-ID: <20161103141559.GQ22791@arm.com> References: <20161031194414.61287-1-code@mmayer.net> <20161102210331.GJ22791@arm.com> <20161102212747.GL22791@arm.com> <2d72cbbb-df03-267c-53b0-e3083a746175@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <2d72cbbb-df03-267c-53b0-e3083a746175@gmail.com> 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 Wed, Nov 02, 2016 at 02:57:26PM -0700, Florian Fainelli wrote: > On 11/02/2016 02:41 PM, Markus Mayer wrote: > > On 2 November 2016 at 14:27, Will Deacon wrote: > >> On Wed, Nov 02, 2016 at 02:07:17PM -0700, Markus Mayer wrote: > >>> The question I am asking is: What do we have to lose by supporting both options? > >> > >> We end up passing "--fix-cortex-a53" to the linker, without knowing what it > >> might do in the future. > > > > It seems highly unlikely that such a generic option would be added in > > the future, both, because the precedent has been set for topic > > specific options, and because they know it has been used in the past, > > so they wouldn't add a previously used option to do something > > completely different. (And if they really did, then that would be a > > huge binutils bug.) > > > > So, we have a trade-off between a real world problem that does > > currently exist and avoiding a theoretical issue that may never > > materialize. > > Agreed, also the way Markus' patch is designed makes it such that we > first try the full and current option name, and if not supported, try > the second (and earlier, now obsolete) option name, so I really don't > see a lot of room for things to go wrong here... It's not beyond the realms of possibility that ld will grow a "fix-cortex-a53" option in the future, that enables all of the a53 workarounds. Since ld is the linker supported by the kernel and gold isn't, I don't want to pass this option down. If you can't change toolchain and you want this worked around, why can't you either build gold with it enabled by default, or pass the extra flag on the command line to the kernel build system? Will