Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1951438AbdDYRCP (ORCPT ); Tue, 25 Apr 2017 13:02:15 -0400 Received: from mail-oi0-f47.google.com ([209.85.218.47]:36205 "EHLO mail-oi0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1945895AbdDYRCF (ORCPT ); Tue, 25 Apr 2017 13:02:05 -0400 MIME-Version: 1.0 In-Reply-To: <89cc7192100bdc9ce546bf6000446e629457ebc1.1493138693.git.leonard.crestez@nxp.com> References: <89cc7192100bdc9ce546bf6000446e629457ebc1.1493138693.git.leonard.crestez@nxp.com> From: Fabio Estevam Date: Tue, 25 Apr 2017 14:02:04 -0300 Message-ID: Subject: Re: [PATCH] ARM: dts: imx6sx-sdb: Remove cpufreq OPP override To: Leonard Crestez Cc: Shawn Guo , Sascha Hauer , Peter Chen , Anson Huang , "linux-pm@vger.kernel.org" , Viresh Kumar , "Rafael J. Wysocki" , linux-kernel , Fabio Estevam , "linux-arm-kernel@lists.infradead.org" , Christoph Fritz Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1329 Lines: 31 Hi Leonard, On Tue, Apr 25, 2017 at 1:57 PM, Leonard Crestez 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. > > Signed-off-by: Leonard Crestez > > --- > It's not clear exactly why the crashes happen. Perhaps waking up from idle > draws more power than is available? Removing this override is a correct > change anyway so maybe there is no need to investigate deeper. Marek just sent a similar one a few minutes ago: http://lists.infradead.org/pipermail/linux-arm-kernel/2017-April/503230.html