From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shawn Guo Subject: Re: [PATCH v2] ARM: dts: imx6sx-sdb: Remove OPP override Date: Wed, 10 May 2017 22:49:04 +0800 Message-ID: <20170510144903.GC5833@dragon> References: <7b929a65b4893e081c2c04bb0588801f37ac2cca.1493981825.git.leonard.crestez@nxp.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail.kernel.org ([198.145.29.136]:40726 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751430AbdEJOtU (ORCPT ); Wed, 10 May 2017 10:49:20 -0400 Content-Disposition: inline In-Reply-To: <7b929a65b4893e081c2c04bb0588801f37ac2cca.1493981825.git.leonard.crestez@nxp.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Leonard Crestez Cc: linux-arm-kernel@lists.infradead.org, Sascha Hauer , Anson Huang , Robin Gong , Peter Chen , Fabio Estevam , Henri Roosen , Marek Vasut , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org On Fri, May 05, 2017 at 02:00:17PM +0300, Leonard Crestez wrote: > The board file for imx6sx-sdb 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 only applies to LDO bypass mode, a feature not present in upstream. > When LDOs are enabled the effect is to use higher voltages than necessary > 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 only > happen on board rev. C, rev. B is reported to still work. > > Signed-off-by: Leonard Crestez > CC: stable@vger.kernel.org It should have the Fixes tag below. I can add it when applying. Fixes: 54183bd7f766 ("ARM: imx6sx-sdb: add revb board and make it default") > > --- > > It is not known exactly why setting these higher voltages causes crashes. > Maybe this means that it's not appropriate to CC stable? It should depend on whether we care about the crashes on stable kernel running on Rev C board. Do we? Shawn > > Removing this override is a correct change anyway because these OPP > overrides do not serve a purpose without ldo bypass. > > Changes since v1: > - Adjusted commit message > - Link: https://lkml.org/lkml/2017/4/25/636 > > arch/arm/boot/dts/imx6sx-sdb.dts | 17 ----------------- > 1 file changed, 17 deletions(-) > > diff --git a/arch/arm/boot/dts/imx6sx-sdb.dts b/arch/arm/boot/dts/imx6sx-sdb.dts > index 5bb8fd5..d71da30 100644 > --- a/arch/arm/boot/dts/imx6sx-sdb.dts > +++ b/arch/arm/boot/dts/imx6sx-sdb.dts > @@ -12,23 +12,6 @@ > model = "Freescale i.MX6 SoloX SDB RevB Board"; > }; > > -&cpu0 { > - operating-points = < > - /* kHz uV */ > - 996000 1250000 > - 792000 1175000 > - 396000 1175000 > - 198000 1175000 > - >; > - fsl,soc-operating-points = < > - /* ARM kHz SOC uV */ > - 996000 1250000 > - 792000 1175000 > - 396000 1175000 > - 198000 1175000 > - >; > -}; > - > &i2c1 { > clock-frequency = <100000>; > pinctrl-names = "default"; > -- > 2.7.4 >