From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758847Ab3BVS12 (ORCPT ); Fri, 22 Feb 2013 13:27:28 -0500 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:38165 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758184Ab3BVS1X (ORCPT ); Fri, 22 Feb 2013 13:27:23 -0500 Date: Fri, 22 Feb 2013 18:27:06 +0000 From: Will Deacon To: Stephen Boyd Cc: "linux-arm-kernel@lists.infradead.org" , "linux-arm-msm@vger.kernel.org" , Steve Muckle , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] ARM: vfp: fix fpsid register subarchitecture field mask width Message-ID: <20130222182705.GC19527@mudshark.cambridge.arm.com> References: <1361520485-30269-1-git-send-email-sboyd@codeaurora.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1361520485-30269-1-git-send-email-sboyd@codeaurora.org> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi guys, On Fri, Feb 22, 2013 at 08:08:05AM +0000, Stephen Boyd wrote: > From: Steve Muckle > > The subarchitecture field in the fpsid register is 7 bits wide. > The topmost bit is used to designate that the subarchitecture > designer is not ARM. We use this field to determine which VFP > version is supported by the CPU. Since the topmost bit is masked > off we detect non-ARM subarchitectures as supporting only > HWCAP_VFP and not HWCAP_VFPv3 as it should be for Qualcomm's > processors. I'm struggling to see why this has anything to do with the hwcaps being set incorrectly. What value do you have in fpsid? As far as I can tell, the subarchitecture bits 6:0 should start at 0x40 for you, right? I can see cases for changing this code, I just don't see why it would go wrong in the case you're describing. Cheers, Will