AM4376: CPSW: prioritize ethernet ports

We use dual-mac configuration.

We would be able to use eth0 for non realtime communication: online access to the device, and eth1 for realtime case: EtherCAT.

Best regards

Walter.

Hi,

I will research your request. At the moment I am not aware of how the two ports could be prioritized since it is the same driver that services both ports. Do you have any additional requirements, for example is there time requirement here?

Best Regards,

Schuyler

Hi Schuyler,

many thanks for the fast answer !

We have one port for online access (console etc) and second port for hard realtime: cyclic time 1..2 ms, when possible without interrupting by first port !

We thought to prioritize IRQs, but these both IRQs are shared by both ports, seams to be Rx & Tx IRQ ? Now we search for other possibility to prioritize.

Best Regards

Walter.

Hi

Depending on your kernel (SDK) version, which you haven't mentioned actually, the TX QoS supported described in https://www.kernel.org/doc/html/latest/networking/device_drivers/ethernet/ti/cpsw.html.

RX QoS/multiq is enabled, but not actually supported - there is possibility to have >1 RX queue, but RX0 is used for all traffic always. Potentially it can be possible change it using CPSW_PORT_P0_CPDMA_RX_CH_MAP and adjusting cpsw_rx_mq_poll to process some RX channel first. Again this is not verified under Linux and not supported by current driver.

The shared IRQs might still be a problem thought.