AM3352: VLAN config is needed if a MAC-to-MAC connected switch is used?

e f

Part Number: AM3352

Tool/software:

Since the switch (KSZ8895) is already configured for VLANs and is connected via MII MAC-to-MAC to the AM3352's EMAC Port 2, you don't need to configure VLAN on the AM3352 itself. The switch will handle VLAN tagging/untagging and forwarding of packets accordingly.

In this scenario, the AM3352's EMAC Port 2 is essentially a simple Ethernet interface that receives and transmits raw Ethernet frames without any VLAN processing. The switch (KSZ8895) takes care of VLAN-related operations, so you can focus on configuring VLANs on the switch itself if needed.

Is this correct?

over 1 year ago

0 Schuyler Patton over 1 year ago

TI__Mastermind 41240 points

Hi,

To my knowledge this may not be correct. The CPSW will configure a VLAN .for each external port. From an external perspective the VLAN tag is applied during packet ingress to the CPSW and stripped on egress. The VLAN IDs are configurable in the DTS file.

Best Regards,

Schuyler

0 e f over 1 year ago in reply to Schuyler Patton

Prodigy 200 points

Hi,

Means there is no way to have transparent character of SOC if another IC is already configured for VLAN?

Is there an example for DTS with VLAN IDs?

0 Schuyler Patton over 1 year ago in reply to e f

TI__Mastermind 41240 points

Hi,

Here is the device tree bindings document:

https://www.kernel.org/doc/Documentation/devicetree/bindings/net/ti%2Ccpsw-switch.yaml

Look for this property:

ti,dual-emac-pvid, the example shows the default values. You could perhaps try moving them to another VID.

Best Regards,

Schuyler

0 e f over 1 year ago in reply to Schuyler Patton

Prodigy 200 points

In page 2080 in https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf?ts=1729160737840

there is

bypassmode. Could this maybe help to have transparent character regarding VLAN? Why is it not possible to configure am3352 in such way, that all ethernet packets will be forwarded unprocessed?

Also please clarify

EN_VID0_MODE R/W-0 0 Enable VLAN ID = 0 Mode 0 - Process the packet with VID = PORT_VLAN[ 11:0]. 1 - Process the packet with VID = 0.

What does this mean?

Processors

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AM3352: VLAN config is needed if a MAC-to-MAC connected switch is used?