Re: MT7530 bug, forward broadcast and unknown frames to the correct CPU port

Vladimir Oltean
2023-05-10T14:03:05Z

On Wed, May 10, 2023 at 10:59:36AM +0200, Arınç ÜNAL wrote:
> > You seem to be rather talking about MT7530 while I think preferring port 6
> > would benefit MT7531BE the most.
> >
> > Can you test the actual speed with SGMII on MT7531? Route between two ports and
> > do a bidirectional iperf3 speed test.
> >
> > SGMII should at least provide you with 2 Gbps bandwidth in total in a
> > router-on-a-stick scenario which is the current situation until the changing
> > DSA conduit support is added.
> >
> > If we were to use port 5, download and upload speed would be capped at 500
> > Mbps. With SGMII you should get 1000 Mbps on each.
>
> I tested this on Daniel's Banana Pi BPI-R3 which has got an MT7531AE switch.
> I can confirm I get more than 500 Mbps for RX and TX on a bidirectional
> speed test.
>
> [SUM][RX-S] 0.00-18.00 sec 1.50 GBytes 715 Mbits/sec receiver
>
> [SUM][TX-S] 0.00-18.00 sec 1.55 GBytes 742 Mbits/sec 6996 sender
>
> The test was run between two computers on different networks, 192.168.1.0/24
> and 192.168.2.0/24, both computers had static routes to reach each other. I
> tried iperf3 as the server and client on both computers with similar
> results.
>
> This concludes preferring port 6 is practically beneficial for MT7531BE.

One thing you seem to not realize is that "1 Gbit/sec full duplex" means
that there is 1Gbps of bandwidth in the TX direction and 1 Gbps of
bandwidth of throughput in the RX direction. So, I don't see how your
test proves anything, since a single SGMII full duplex link to the CPU
should be able to absorb your 715 RX + 742 TX traffic just fine.