Re: [PATCH 2.6.33 1/3] net: Micrel KSZ8841/2 PCI Ethernet driver

From: Michał Mirosław
Date: Sat Jan 16 2010 - 11:01:00 EST


2010/1/16 Ha, Tristram <Tristram.Ha@xxxxxxxxxx>:
> This is a new network driver for Micrel KSZ8841/KSZ8842 PCI Ethernet chips.  The same driver can run both chips at the same time.  It supports IPv4 TCP hardware checksumming and so can use scatter/gather transmission.
> The KSZ8842 has a switch with lots of hardware configurations.  The driver uses the proc system to allow users to configure the switch.  If this is not desired the whole thing can be removed by not calling the init_proc() function.
> The KSZ8842 switch has 2 ports.  Some users like to take direct control of those ports.  So KSZ8842 has a multiple devices mode in which the driver creates another network device so that users can specify which port to send packets.  This mode is enabled by passing the "multi_dev=1" parameter to the driver during loading.

I briefly looked over the datasheet for your device and it looks like
it has the same basic design idea as a "ROBO" switch from Broadcom
that is used in bcm53xx SoCs. This can be seen as a 3-port switch with
one port fixed to be link to CPU (a special kind of PHY).

If my assumptions are correct, then I thing it would be better to have
a driver that presents this device as two: one - an ethernet device,
and second - a switch management interface like the one used in

Here are some links for reference:;
subdir: package/switch/src/
-> switch management driver for ADMTEK Adm6996 and Broadcom BCM5325E/536x

(I'm adding switch driver's authors to CC list. I hope I picket the
correct address for Felix from 3 in the sources. :-)

Best Regards,
Michał Mirosław
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