Re: [PATCH v6 5/9] dt-bindings: ARM: document marvell,ecc-enable binding

[Russell King - ARM Linux]

On Fri, Nov 09, 2018 at 12:40:06PM +0100, Arnd Bergmann wrote:
> On Fri, Nov 9, 2018 at 8:04 AM Chris Packham
> <chris.packham@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > Add documentation for the marvell,ecc-enable and marvell,ecc-disable
> > properties which can be used to enable/disable ECC on the Marvell aurora
> > cache.
> >
> > Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> > ---
> 
> Why do you need both enable and disable? Wouldn't one of them be enough here?

It isn't an "on when ecc-enable is present, off when not" because the
current behaviour is to preserve these bits in the control register.

If we were to implement it as "if no ecc-enable property, turn off
ECC" then that would drastically change the behaviour - systems which
were configured for ECC suddenly lose ECC support.

Since we don't know which have it and which don't, we can't implement
the option like that.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up