From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753294AbcBAT6T (ORCPT ); Mon, 1 Feb 2016 14:58:19 -0500 Received: from smtp.codeaurora.org ([198.145.29.96]:54736 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751677AbcBAT6S (ORCPT ); Mon, 1 Feb 2016 14:58:18 -0500 Date: Mon, 1 Feb 2016 11:58:16 -0800 From: Stephen Boyd To: Robin Murphy Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, daniel.lezcano@linaro.org, tglx@linutronix.de, mark.rutland@arm.com Subject: Re: [PATCH v2] clocksource/arm_arch_timer: Enable and verify MMIO access Message-ID: <20160201195816.GL4848@codeaurora.org> References: <71bf617f4083b116b2aeab24f13fc5fed99a816f.1454327031.git.robin.murphy@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <71bf617f4083b116b2aeab24f13fc5fed99a816f.1454327031.git.robin.murphy@arm.com> 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 On 02/01, Robin Murphy wrote: > So far, we have been blindly assuming that having access to a > memory-mapped timer frame implies that the individual elements of that > frame frame are already enabled. Whilst it's the firmware's job to give > us non-secure access to frames in the first place, we should not rely > on implementations always being generous enough to also configure CNTACR > for those non-secure frames (e.g. [1]). > > Explicitly enable feature-level access per-frame, and verify that the > access we want is really implemented before trying to make use of it. > > [1]:https://github.com/ARM-software/tf-issues/issues/170 > > Signed-off-by: Robin Murphy > --- Reviewed-by: Stephen Boyd Tested-by: Stephen Boyd -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project