From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932453AbdEDLoY (ORCPT ); Thu, 4 May 2017 07:44:24 -0400 Received: from mail.kernel.org ([198.145.29.136]:48474 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753024AbdEDLoM (ORCPT ); Thu, 4 May 2017 07:44:12 -0400 Date: Thu, 4 May 2017 19:43:45 +0800 From: Shawn Guo To: Peter Chen Cc: Leonard Crestez , Sascha Hauer , Anson Huang , Robin Gong , "linux-pm@vger.kernel.org" , Viresh Kumar , "Rafael J. Wysocki" , "linux-kernel@vger.kernel.org" , Fabio Estevam , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH] ARM: dts: imx6sx-sdb: Remove cpufreq OPP override Message-ID: <20170504114343.GN18578@dragon> References: <89cc7192100bdc9ce546bf6000446e629457ebc1.1493138693.git.leonard.crestez@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 Thu, Apr 27, 2017 at 01:17:12AM +0000, Peter Chen wrote: > > > > >The board file for imx6sx-dbg overrides cpufreq operating points to use higher > >voltages. This is done because the board has a shared rail for VDD_ARM_IN and > >VDD_SOC_IN and when using LDO bypass the shared voltage needs to be a value > >suitable for both ARM and SOC. > > > >This was introduced in: > > > >commit 54183bd7f766 ("ARM: imx6sx-sdb: add revb board and make it default") > > > >This only only applies to LDO bypass mode, a feature not present in upstream. When > >LDOs are enabled the effect is to use higher voltages than necesarry for no good > >reason. > > > >Setting these higher voltages can make some boards fail to boot with ugly semi- > >random crashes, reminiscent of memory corruption. These failures happen the first > >time the lowest idle state is used. Remove the OPP override in order to fix those > >crashes. > > > > Add Anson and Robin > > This code has existed more than 2 years, it is strange why the bug has not reported both > for internal user and external user. I run upstream kernel using imx6sx-sdb revB very often > at recent years, but not meet this issue. How to trigger this unstable issue, anything needs > to change at u-boot? Per comments from Henri and Leonard, it sounds like the issue only happens on RevC board? Shawn