From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753258AbaIXSLs (ORCPT ); Wed, 24 Sep 2014 14:11:48 -0400 Received: from mail-pa0-f54.google.com ([209.85.220.54]:52722 "EHLO mail-pa0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751301AbaIXSLr (ORCPT ); Wed, 24 Sep 2014 14:11:47 -0400 Message-ID: <5423095F.9030802@converseincode.com> Date: Wed, 24 Sep 2014 11:11:43 -0700 From: Behan Webster User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.1 MIME-Version: 1.0 To: Arnd Bergmann , linux-arm-kernel@lists.infradead.org CC: linux@arm.linux.org.uk, linux@prisktech.co.nz, linux-kernel@vger.kernel.org Subject: Re: [PATCH] arm, vt8500, LLVMLlinux: Use mcr instead of mcr% for mach-vt8500 References: <1411530284-28807-1-git-send-email-behanw@converseincode.com> <7810937.UX61PvX9nB@wuerfel> In-Reply-To: <7810937.UX61PvX9nB@wuerfel> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 09/24/14 02:16, Arnd Bergmann wrote: > On Tuesday 23 September 2014 20:44:44 Behan Webster wrote: >> The ASM below does not compile with clang and is not the way that the mcr >> command is used in other parts of the kernel. >> >> arch/arm/mach-vt8500/vt8500.c:72:11: error: invalid % escape in inline assembly string >> asm("mcr%? p15, 0, %0, c7, c0, 4" : : "r" (0)); >> ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~ >> 1 error generated. >> >> There are other forms that are supported on different ARM instruction sets but >> generally the kernel just uses mcr as it is supported in all ARM instruction >> sets. > Just for confirm: both forms are actually correct and we don't need this > backported for stable, right? My understanding is that the %? carries a condition code to the next instruction (which in this case is then ignored). So essentially in this situation both are equivalent. >> Signed-off-by: Behan Webster >> Reviewed-by: Mark Charlebois >> Acked-by: Will Deacon > Acked-by: Arnd Bergmann > > Tony, would you like to pick this one up and send it in a pull request > to arm-soc, or should we apply it to fixes-non-critical directly? Thanks, Behan -- Behan Webster behanw@converseincode.com