From patchwork Tue Feb 19 10:16:13 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joseph Lo X-Patchwork-Id: 2162381 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork1.kernel.org (Postfix) with ESMTP id 486AF3FDF1 for ; Tue, 19 Feb 2013 10:19:01 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1U7kFN-0001v5-FQ; Tue, 19 Feb 2013 10:16:25 +0000 Received: from hqemgate04.nvidia.com ([216.228.121.35]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1U7kFK-0001u3-DI for linux-arm-kernel@lists.infradead.org; Tue, 19 Feb 2013 10:16:23 +0000 Received: from hqnvupgp07.nvidia.com (Not Verified[216.228.121.13]) by hqemgate04.nvidia.com id ; Tue, 19 Feb 2013 02:16:12 -0800 Received: from hqemhub02.nvidia.com ([172.20.150.31]) by hqnvupgp07.nvidia.com (PGP Universal service); Tue, 19 Feb 2013 02:15:41 -0800 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Tue, 19 Feb 2013 02:15:41 -0800 Received: from jlo-ubuntu-64.nvidia.com (172.20.144.16) by hqemhub02.nvidia.com (172.20.150.31) with Microsoft SMTP Server (TLS) id 8.3.297.1; Tue, 19 Feb 2013 02:16:20 -0800 From: Joseph Lo To: Stephen Warren Subject: [PATCH] ARM: tegra: don't unlock MMIO access to DBGLAR Date: Tue, 19 Feb 2013 18:16:13 +0800 Message-ID: <1361268973-14584-1-git-send-email-josephl@nvidia.com> X-Mailer: git-send-email 1.8.1.1 X-NVConfidentiality: public MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130219_051622_591591_CFF3228B X-CRM114-Status: UNSURE ( 9.11 ) X-CRM114-Notice: Please train this message. X-Spam-Score: -7.6 (-------) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-7.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -5.0 RCVD_IN_DNSWL_HI RBL: Sender listed at http://www.dnswl.org/, high trust [216.228.121.35 listed in list.dnswl.org] -0.0 SPF_HELO_PASS SPF: HELO matches SPF record -0.0 SPF_PASS SPF: sender matches SPF record -0.7 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: linux-tegra@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Joseph Lo X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org There is no need to unlock MMIO access to the DBGLAR all the time. Doing so may even cause problems if a SW bug causes writes to that MMIO region. Cortex-A15 processors do not support the CP14 register write the code currently uses to unlock the DBGLAR; the instruction throws an undefined instruction exceptions. This prevents tegra_secondary_startup() from executing on Tegra114, and hence prevents SMP. Remove the code that unlocks this access. Signed-off-by: Joseph Lo --- arch/arm/mach-tegra/headsmp.S | 3 --- arch/arm/mach-tegra/reset-handler.S | 3 --- 2 files changed, 6 deletions(-) diff --git a/arch/arm/mach-tegra/headsmp.S b/arch/arm/mach-tegra/headsmp.S index fd473f2..045c16f 100644 --- a/arch/arm/mach-tegra/headsmp.S +++ b/arch/arm/mach-tegra/headsmp.S @@ -7,8 +7,5 @@ ENTRY(tegra_secondary_startup) bl v7_invalidate_l1 - /* Enable coresight */ - mov32 r0, 0xC5ACCE55 - mcr p14, 0, r0, c7, c12, 6 b secondary_startup ENDPROC(tegra_secondary_startup) diff --git a/arch/arm/mach-tegra/reset-handler.S b/arch/arm/mach-tegra/reset-handler.S index 54382ce..68b8bfc 100644 --- a/arch/arm/mach-tegra/reset-handler.S +++ b/arch/arm/mach-tegra/reset-handler.S @@ -41,9 +41,6 @@ */ ENTRY(tegra_resume) bl v7_invalidate_l1 - /* Enable coresight */ - mov32 r0, 0xC5ACCE55 - mcr p14, 0, r0, c7, c12, 6 cpu_id r0 cmp r0, #0 @ CPU0?