Re: [PATCH] ARM: dts: imx6sx-sdb: Remove cpufreq OPP override

From: Shawn Guo
Date: Thu May 04 2017 - 07:44:27 EST

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?