Re: [ethernet/broadcom/bgmac]: Implement software multicast filter clear

From: Florian Fainelli
Date: Thu Apr 17 2025 - 14:00:42 EST


Howdy,

On 4/13/25 00:25, Ujwal Kundur wrote:
Hi,
I'm trying to work on a few TODOs in the
drivers/net/ethernet/broadcom/bgmac.c driver code and came across the
"Clear software multicast filter list" item.
I tried comparing the multicast filter implementation of the
sb1250-mac.c driver for inspiration but realized that most of the code
for bgmac has been written by reverse-engineering the specs:
hhttps://bcm-v4.sipsolutions.net/Specification/

I'd like to try my hand at this if there are documents/guides
around this topic or if there's a canonical source for the binary that
I can try reverse engineering. Please let me know if you have any
leads/advice.

Given that these controllers are always interfaced with either an integrated or an external Ethernet switch chip, the design was done assuming that the switch will be operated in managed mode and multicast filtering will be done on the switch side.

It's been a while since I looked at that part of the DSA and bridge stack, but we should be pretty close to having that capability nowadays.
--
Florian