[U-Boot] [PATCH 1/3] ARM: implement some Cortex-A9 errata workarounds

[Albert ARIBAUD]

Hi Tom,

On Mon, 4 Mar 2013 08:30:11 -0800, Tom Warren <TWarren at nvidia.com>
wrote:

> Stephen & Albert,
> 
> > -----Original Message-----
> > From: Stephen Warren [mailto:swarren at wwwdotorg.org]
> > Sent: Friday, March 01, 2013 2:54 PM
> > To: Tom Warren
> > Cc: u-boot at lists.denx.de; Stephen Warren
> > Subject: Re: [U-Boot] [PATCH 1/3] ARM: implement some Cortex-A9 errata
> > workarounds
> > 
> > On 02/28/2013 10:08 AM, Stephen Warren wrote:
> > > On 02/26/2013 03:28 PM, Stephen Warren wrote:
> > >> From: Stephen Warren <swarren at nvidia.com>
> > >>
> > >> Various errata exist in the Cortex-A9 CPU, and may be worked around
> > >> by setting some bits in a CP15 diagnostic register. Add code to
> > >> implement the workarounds, enabled by new CONFIG_ options.
> > >>
> > >> This code was taken from the Linux kernel, v3.8,
> > >> arch/arm/mm/proc-v7.S, and modified to remove the logic to
> > >> conditionally apply the WAR (since we know exactly which CPU we're
> > >> running on given the U-Boot configuration), and use r0 instead of r10
> > >> for consistency with the rest of U-Boot's cpu_init_cp15().
> > >
> > > Hmmm. Lets hold off on this series; there are some conditions under
> > > which the kernel has to be able to apply these WARs anyway (e.g. SMP
> > > CPU power saving), which may impact which of the WARs the bootloader
> > > should apply even when booting the initial CPU 0. I'll repost once
> > > that's been resolved.
> > 
> > Tom,
> > 
> > It looks like the bootloader should always apply these WARs for CPU 0.
> > We just have to make sure that the kernel applies them for CPUs 1..n if/when
> > running in secure mode.
> > 
> > In other words, I think these patches are good to go in as-is. Since there
> > are no changes to the patches, I won't repost them, unless you need me to.
> 
> I can take these in via the Tegra tree, but the bulk of the changes are for ARM, not Tegra.
> Albert - do you want to take this directly into the ARM repo, or would you prefer me to take it?

I will take them in tonight.

> Tom
> --
> nvpublic

Amicalement,
-- 
Albert.