From patchwork Tue Sep 1 13:08:49 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marek Szyprowski X-Patchwork-Id: 7105271 Return-Path: X-Original-To: patchwork-linux-samsung-soc@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 867B09F36E for ; Tue, 1 Sep 2015 13:09:09 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 99F5420602 for ; Tue, 1 Sep 2015 13:09:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 84A16205F5 for ; Tue, 1 Sep 2015 13:09:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753772AbbIANJF (ORCPT ); Tue, 1 Sep 2015 09:09:05 -0400 Received: from mailout2.w1.samsung.com ([210.118.77.12]:29333 "EHLO mailout2.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753750AbbIANJE (ORCPT ); Tue, 1 Sep 2015 09:09:04 -0400 Received: from eucpsbgm1.samsung.com (unknown [203.254.199.244]) by mailout2.w1.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTP id <0NU000GJV1V2RP60@mailout2.w1.samsung.com> for linux-samsung-soc@vger.kernel.org; Tue, 01 Sep 2015 14:09:02 +0100 (BST) X-AuditID: cbfec7f4-f79c56d0000012ee-a1-55e5a36e18c2 Received: from eusync3.samsung.com ( [203.254.199.213]) by eucpsbgm1.samsung.com (EUCPMTA) with SMTP id 72.3C.04846.E63A5E55; Tue, 1 Sep 2015 14:09:02 +0100 (BST) Received: from amdc1339.digital.local ([106.116.147.30]) by eusync3.samsung.com (Oracle Communications Messaging Server 7.0.5.31.0 64bit (built May 5 2014)) with ESMTPA id <0NU000DHP1UYVX10@eusync3.samsung.com>; Tue, 01 Sep 2015 14:09:02 +0100 (BST) From: Marek Szyprowski To: linux-samsung-soc@vger.kernel.org Cc: Marek Szyprowski , Kukjin Kim , Krzysztof Kozlowski , Tobias Jakobi , Bartlomiej Zolnierkiewicz Subject: [PATCH] ARM: dts: exynos4412-odroid-*: add workaround for CPUfreq/reboot issue Date: Tue, 01 Sep 2015 15:08:49 +0200 Message-id: <1441112929-6751-1-git-send-email-m.szyprowski@samsung.com> X-Mailer: git-send-email 1.9.2 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFvrIJMWRmVeSWpSXmKPExsVy+t/xq7p5i5+GGvx/ImuxccZ6VovXLwwt +h+/ZraYcX4fk8XaI3fZLdpWf2B1YPPYtKqTzePfMXaPvi2rGD0+b5ILYInisklJzcksSy3S t0vgyvh66gJzwQb+it8TT7M1MD7g6WLk5JAQMJFYPukMC4QtJnHh3nq2LkYuDiGBpYwSv771 M0M4TUwS258vZgKpYhMwlOh628UGYosIqEp8blvADlLELPCCUeLDtwtgRcICkRJneqeyg9gs QEXLp7eAreAVcJdoWfuWDWKdnMT/lyuYJjByL2BkWMUomlqaXFCclJ5rqFecmFtcmpeul5yf u4kREhBfdjAuPmZ1iFGAg1GJh7fj45NQIdbEsuLK3EOMEhzMSiK87xc8DRXiTUmsrEotyo8v Ks1JLT7EKM3BoiTOO3fX+xAhgfTEktTs1NSC1CKYLBMHp1QD47zLLAkznnzTqfw6cfWUfu01 j74kdwUHLe2zWHXNXzA123Sx1bMj87xKJZ3mXexaO0FP6kb1qf0BPDfW+OieUDiU3HAx/80R Z+Fwyecq8674nFtyVuwf/5wFJ9+kO77iXFFyYP3JabtEz28VUBbOuBilYGXGdkZtk1tL1lGt dXwvumtWFOza+VWJpTgj0VCLuag4EQAed+txBAIAAA== Sender: linux-samsung-soc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Exynos4412-based Odroid boards (X2, U3, U3+) don't reset PMIC configuration during hardware reset. This causes serious issues with CPUfreq, when ARM voltage is set below 1.0V. When one resets the board when CPUfreq selected one of lower Exynos 4412 operating points (for example: 200MHz and 0.9V), the bootloader crashes and it is not possible to restart the board without turning power off. This patch provides a workaround for this issue by increasing the start of valid range for vdd_arm regulator from 1.0V. After such change, CPUfreq can still use lower operating points, but the voltage won't be decreased below 1.0V and as a result it will be possible to reset board at any time. Signed-off-by: Marek Szyprowski Reviewed-by: Krzysztof Kozlowski --- Hello, This issue was there from the beggining, but I was not able to reproduce it. It has been already reported by Tobias in early Feb 2015 (http://www.spinics.net/lists/linux-samsung-soc/msg42294.html). Recently, after CPUfreq changes (conversion to generic cpufreq dt and enabling cpufreq in exynos_defconfig) it was much easier to observe this issue. This workaround lets one still use CPUfreq and avoid unexpect board crashes during reboot (both 'standard' and emergency). Best regards Marek Szyprowski, PhD Samsung R&D Institute Poland --- arch/arm/boot/dts/exynos4412-odroid-common.dtsi | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi index db52841..fca8233 100644 --- a/arch/arm/boot/dts/exynos4412-odroid-common.dtsi +++ b/arch/arm/boot/dts/exynos4412-odroid-common.dtsi @@ -370,7 +370,7 @@ buck2_reg: BUCK2 { regulator-name = "vdd_arm"; - regulator-min-microvolt = <900000>; + regulator-min-microvolt = <1000000>; regulator-max-microvolt = <1350000>; regulator-always-on; regulator-boot-on;