Re: [PATCH V2 00/14] net: ks8851: Unify KS8851 SPI and MLL drivers

On Wed, Mar 25, 2020 at 04:05:29PM +0100, Marek Vasut wrote:

quoted

The KS8851SNL/SNLI and KS8851-16MLL/MLLI/MLLU are very much the same pieces
of silicon, except the former has an SPI interface, while the later has a
parallel bus interface. Thus far, Linux has two separate drivers for each
and they are diverging considerably.

This series unifies them into a single driver with small SPI and parallel
bus specific parts. The approach here is to first separate out the SPI
specific parts into a separate file, then add parallel bus accessors in
another separate file and then finally remove the old parallel bus driver.
The reason for replacing the old parallel bus driver is because the SPI
bus driver is much higher quality.

With this series, ks8851.ko (SPI variant) failed to compile as a module.
I got it working by renaming ks8851.c to ks8851_common.c and applying
the following change to the Makefile:

--- a/drivers/net/ethernet/micrel/Makefile
+++ b/drivers/net/ethernet/micrel/Makefile

@@ -5,6 +5,8 @@
 
 obj-$(CONFIG_ARM_KS8695_ETHER) += ks8695net.o
 obj-$(CONFIG_KS8842) += ks8842.o
-obj-$(CONFIG_KS8851) += ks8851.o ks8851_spi.o
-obj-$(CONFIG_KS8851_MLL) += ks8851.o ks8851_par.o
+obj-$(CONFIG_KS8851) += ks8851.o
+ks8851-objs = ks8851_common.o ks8851_spi.o
+obj-$(CONFIG_KS8851_MLL) += ks8851_mll.o
+ks8851_mll-objs = ks8851_common.o ks8851_par.o
 obj-$(CONFIG_KSZ884X_PCI) += ksz884x.o

This series breaks reading the MAC address from an EEPROM attached to
the KSZ8851SNLI:
The MAC address stored in the EEPROM was c8:3e:a7:99:ef:aa.
The MAC address was read as 3e:c8:99:a7:ef:aa with this series.
Note: The MAC address starts at the third byte in the EEPROM and is
stored as aa:ef:99:a7:3e:c8, i.e. in reverse order.  (I think the
spec says something else but it appears to be wrong.)

Assigning a MAC address with "ifconfig eth1 hw ether <mac>" (which I
believe ends up calling ks8851_write_mac_addr()) worked fine.