TDA4VH-Q1: TDA4VH: 802.1Qbv(EST) drop packet

sun ruijie

Intellectual 583 points

Part Number: TDA4VH-Q1
Other Parts Discussed in Thread: TDA4VH

Tool/software:

Hi TI experts,

We are using tda4vh SDK0900 linux native driver to test EST. The network topology is as follows:

The config of TDA4vh:

We tested EST with iperf3, we configured EST on top of interface eth0, which is a gigabit network port. We have priority 0 to 6 in EST in a 40us time slice and priority 7 in another time slice of 40us. So we think the rate of udp testing through iperf3 should be about 500M, but after our actual testing, the packet rate of priority 6 and priority 7 is about 300M only.

We found a lot of packet loss on the eth0 interface.

Why is the rate of priority 7 packets not half the rate of the gigabit port after the time slice is split equally on the gigabit port eth0?

Best Regards,
Ruijie

4 months ago

0 Tanmay Patil 4 months ago

TI__Mastermind 30430 points

Hi Ruijie,

Can you confirm that eth0 belongs to CPSW9G and not CPSW2G(default case). Basically that you have disabled mcu_cpsw node from device-tree?

This is a incorrect qdisc. The property "queues 4@4 4@4" is incorrect. This would mean that you are using the same 4 queues for both traffic classes.

The way to interpret this command is the for tc 0, use 4 queues starting at index 4 and for tc 1, use 4 queues starting at index 4.

For your case, you should use something like "queues 7@0 1@7". This would mean for tc 0, use 7 queues starting at index 0 and for tc 1, use 1 queue starting at index 7.

Note that there are 8 queues in total.

Regards,
Tanmay

0 sun ruijie 4 months ago in reply to Tanmay Patil

Intellectual 583 points

Hi Tanmay,

I'm sure eth0 belongs to CPSW9G. I'm sorry for the mistake about the EST configuration. Here is our EST configuration.

Priority 0 to 6 packets are mapped to tc0, and priority 7 packets are mapped to tc1. tc0 occupies 5 queues, and tc1 occupies 3 queues. tc0 has a time slice of 40us, and tc1 has a time slice of 40us. why is the rate of a priority 7 packet only 300M in the presence of interference with the background flow of priority 6? The rates should be scaled by time slices. So the rate for priority 7 should be about 1G/2 = 500Mbps.

Best Regards,
Ruijie

0 Tanmay Patil 3 months ago in reply to sun ruijie

TI__Mastermind 30430 points

Hi Ruijie,

Can you share the output of "ethtool -S eth0" before and after the iperf. Lets see where are the packets being dropped.

Just one more point, if you are not doing this, can you set the value -b flag in the iperf3 command to 500M for both the priority traffic

Regards,
Tanmay

0 sun ruijie 3 months ago in reply to Tanmay Patil

Intellectual 583 points

Hi Tanmay,

The ip of PC1 is 192.168.7.147, 192.168.8.147 and the ip of PC2 is 192.168.7.149, 192.168.8.149. The PCP of vlan id 7 is 7 and the PCP of vlan id 8 is 6.

The command in PC1: