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

On Sat, Feb 15, 2014 at 02:18:08PM +0100, Arnd Bergmann wrote:

On Saturday 15 February 2014 11:20:03 Andrew Lunn wrote:

quoted

+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