quoted

Should there be -EPROBE_DEFER handling in here somewhere? The SRAM is a
device, so it might not of been probed yet?

No, firmware probed during bootloader boot and we can use SRAM. SRAM
memory can be safely used.

A previous patch added:

+               CP11X_LABEL(cm3_sram): cm3@220000 {
+                       compatible = "mmio-sram";
+                       reg = <0x220000 0x800>;
+                       #address-cells = <1>;
+                       #size-cells = <1>;
+                       ranges = <0 0x220000 0x800>;
+               };
+

So it looks like the SRAM is a device, in the linux driver model. And
there is a driver for this, driver/misc/sram.c. How do you know this
device has been probed before the Ethernet driver?

       Andrew