From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753346AbaISBkg (ORCPT ); Thu, 18 Sep 2014 21:40:36 -0400 Received: from cam-admin0.cambridge.arm.com ([217.140.96.50]:57120 "EHLO cam-admin0.cambridge.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750855AbaISBkf (ORCPT ); Thu, 18 Sep 2014 21:40:35 -0400 Date: Fri, 19 Sep 2014 02:40:01 +0100 From: Will Deacon To: Russell King - ARM Linux Cc: Stephen Boyd , "linux-arm-kernel@lists.infradead.org" , "linux-arm-msm@vger.kernel.org" , Stepan Moskovchenko , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH 3/3] arm: vfp: Bounce undefined instructions in vectored mode Message-ID: <20140919014001.GB20773@arm.com> References: <1411076592-6157-1-git-send-email-sboyd@codeaurora.org> <1411076592-6157-4-git-send-email-sboyd@codeaurora.org> <20140918225531.GG5182@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140918225531.GG5182@n2100.arm.linux.org.uk> 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 Thu, Sep 18, 2014 at 11:55:31PM +0100, Russell King - ARM Linux wrote: > On Thu, Sep 18, 2014 at 02:43:12PM -0700, Stephen Boyd wrote: > > From: Stepan Moskovchenko > > > > Certain ARM CPU implementations (e.g. Cortex-A15) may not raise a > > floating- point exception whenever deprecated short-vector VFP > > instructions are executed. Instead these instructions are treated > > as UNALLOCATED. Change the VFP exception handling code to emulate > > short-vector instructions even if FPEXC exception bits are not > > set. > > Purely out of interest, how much use do these instructions have in > real programs? They're seldom used, but there are apps in the app store that use short vectors to play music. Will