[PATCH v2 05/23] ARM: Kirkwood: Seperate board-dt from common and pcie code.

Andrew Lunn
2014-02-15T14:05:05Z

On Sat, Feb 15, 2014 at 02:18:08PM +0100, Arnd Bergmann wrote:
> On Saturday 15 February 2014 11:20:03 Andrew Lunn wrote:
> > +static void __init kirkwood_l2_init(void)
> > +{
> > +#ifdef CONFIG_CACHE_FEROCEON_L2
> > +#ifdef CONFIG_CACHE_FEROCEON_L2_WRITETHROUGH
> > + writel(readl(L2_CONFIG_REG) | L2_WRITETHROUGH, L2_CONFIG_REG);
> > + feroceon_l2_init(1);
> > +#else
> > + writel(readl(L2_CONFIG_REG) & ~L2_WRITETHROUGH, L2_CONFIG_REG);
> > + feroceon_l2_init(0);
> > +#endif
> > +#endif
> > +}
>
> I assume this is correct, but I don't understand it. Why is there a
> configuration option for this? Do both write-through and write-back
> work on all machines, or could there be a case where some machine
> actually requires a particular mode? If not, isn't write-back
> normally "better", so you won't actually ever want to set write-through
> mode?

Hi Arnd

The honest answer is, i've no idea. I'm just shuffling code around in
this patch, and not applying my brain as to what this code does....

Maybe JasonG has a better idea of this history of this?

Andrew