On Wed, May 22, 2013 at 10:04:02PM +0200, Sebastian Hesselbarth wrote:

Ethernet controllers found on Kirkwood SoCs not only suffer from loosing
MAC address register contents on clock gating but also some important
registers are reset to values that would break ethernet. This patch

FWIW, we found that the bootloader has to write to PSC1, the driver
doesn't work with the power on/reset value of the register. So I think
it is safe to assume that all kirkwood bootloaders alter the value.

Our systems write the value 0x00638488 to PSC1.

I looked at patching mv643xx_eth, but ran into the same complexity you
did, it isn't clear what variants of this IP block have the
register/etc.

+	/* Kirkwood resets some registers on gated clocks. Especially
+	 * CLK125_BYPASS_EN must be cleared but is not available on
+	 * all other SoCs/System Controllers using this driver.
+	 */
+	if (of_machine_is_compatible("marvell,kirkwood"))
+		wrlp(mp, PORT_SERIAL_CONTROL1,
+		     rdlp(mp, PORT_SERIAL_CONTROL1) & ~CLK125_BYPASS_EN);

of_machine_is_compatible seems heavy handed, I would expect this to be
based on the compatible string of the ethernet node itself, not the
machine??

Jason