From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751705AbaILRTT (ORCPT ); Fri, 12 Sep 2014 13:19:19 -0400 Received: from gw-1.arm.linux.org.uk ([78.32.30.217]:53350 "EHLO pandora.arm.linux.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751139AbaILRTR (ORCPT ); Fri, 12 Sep 2014 13:19:17 -0400 Date: Fri, 12 Sep 2014 18:19:08 +0100 From: Russell King - ARM Linux To: Daniel Thompson Cc: linaro-kernel@lists.linaro.org, patches@linaro.org, Catalin Marinas , linux-kernel@vger.kernel.org, John Stultz , Thomas Gleixner , Sumit Semwal , linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH 3.17-rc4 v5 2/6] arm: fiq: Replace default FIQ handler Message-ID: <20140912171908.GP12361@n2100.arm.linux.org.uk> References: <1410272111-30516-1-git-send-email-daniel.thompson@linaro.org> <1410435078-28462-1-git-send-email-daniel.thompson@linaro.org> <1410435078-28462-3-git-send-email-daniel.thompson@linaro.org> <20140912171404.GO12361@n2100.arm.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140912171404.GO12361@n2100.arm.linux.org.uk> User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 12, 2014 at 06:14:04PM +0100, Russell King - ARM Linux wrote: > On Thu, Sep 11, 2014 at 12:31:14PM +0100, Daniel Thompson wrote: > > This patch introduces a new default FIQ handler that is structured in a > > similar way to the existing ARM exception handler and result in the FIQ > > being handled by C code running on the SVC stack (despite this code run > > in the FIQ handler is subject to severe limitations with respect to > > locking making normal interaction with the kernel impossible). > > > > This default handler allows concepts that on x86 would be handled using > > NMIs to be realized on ARM. > > Okay, lastly... I sent you my version of this change, which contained > the changes I've detailed in the previous three emails, which are absent > from your version. > > However, you've taken on board the "trace" thing to svc_entry, and > renamed it to "call_trace". > > Now if I add this to usr_entry, "call_trace" doesn't make any sense, > nor does the .if/.endif placement because it's not just trace_hardirqs_off > which needs to be disabled there, but also ct_user_exit as well. > > I'm beginning to wonder why I tried to be nice here... it would've been > a lot faster for me to take your patch, make my own changes and commit > that instead. > > Frustrated. And another thing you're missing are the updates to arch/arm/kernel/fiq.c to ensure that the FIQ registers are preserved when we restore this new default FIQ handler. -- FTTC broadband for 0.8mile line: currently at 9.5Mbps down 400kbps up according to speedtest.net.