Linux/AM5718: PRU-ICSS Ethernet Linux driver VLAN support

Michael Shklyarman

Part Number: AM5718
Other Parts Discussed in Thread: SYSBIOS

Tool/software: Linux

Champs,

Is Linux PRU Ehternet driver supposed to support VLANs? it appears that the PRU firmware does support VLANs however customer reported that the PRU network ports on IDK do not pass VLAN tagged frames.

could you please clarify?

thanks

Michael

over 8 years ago

0 Pavel Botev over 8 years ago

TI__Guru**** 170625 points

Hi Michael,

Why do you think PRU ethernet firmware support VLAN? We do not provide the source code for the PRU Ethernet firmwares.

From what I was able to find, PRU Ethernet linux driver do not support VLAN, see the below pointers:

processors.wiki.ti.com/.../PRU-ICSS_Ethernet

drivers/net/ethernet/ti/prueth.c

And I can not find hardware VLAN support for PRU-ICSS in AM571x TRM, chapter 30

VLAN seems to be supported only for AM571x CPSW (GMAC_SW) module, for both hardware and linux driver, see the below pointers:

AM571x TRM, chapter 24.11 Gigabit Ethernet Switch (GMAC_SW)

processors.wiki.ti.com/.../Linux_Core_CPSW_User's_Guide

drivers/net/ethernet/ti/cpsw.c

Regards,
Pavel

0 Michael Shklyarman over 8 years ago in reply to Pavel Botev

TI__Genius 12700 points

Pavel,

the PRU ICSS EMAC LLD supports VLANs for QoS so firmware is obviously supporting VLANs too:

http://processors.wiki.ti.com/index.php/ICSS_EMAC_LLD_developers_guide

it would appear though that the Linux ICSS EMAC driver drops the ball somehow...

thanks

Michael

0 Pavel Botev over 8 years ago in reply to Michael Shklyarman

TI__Guru**** 170625 points

Michael,

The wiki page you have provided is valid for AM335x and AM437x, but not for AM57x.

And this wiki seems to be for both PRU-ICSS and EMAC (CPSW, GMAC_SW), and VLANs described are related to EMAC, not to PRU-ICSS.

And the firmware described seems to be different from the one available in PSDK filesystem /lib/firmware/ti-pruss/

And this wiki seems to be regarding SysBIOS SDK, not for PSDK (where linux drivers are available).

Regards,
Pavel

0 Michael Shklyarman over 8 years ago in reply to Pavel Botev

TI__Genius 12700 points

Pavel,

I was actually able to setup a test connecting 2 IDK boards and Ubuntu PC to simple switch w/ VLAN support. one IDK was connected via CPSW port, one via PRU port. I created VLAN interfaces on all 3 nodes and was able to ping across all 3 and also download a file from Ubuntu to IDK over PRU port using wget command.
I believe that VLAN is in fact supported, at least to some extent. Will need to do some further testing and work with customer to reproduce their setup.

thank you,
Michael

0 Pavel Botev over 8 years ago in reply to Michael Shklyarman

TI__Guru**** 170625 points

Michael,

Do you use Processor SDK Linux or Processor SDK RT Linux or Processor SDK RTOS or else?

Regards,
Pavel

0 Michael Shklyarman over 8 years ago in reply to Pavel Botev

TI__Genius 12700 points

I use regular Processors SDK Linux (not RT).

0 Pavel Botev over 8 years ago in reply to Michael Shklyarman

TI__Guru**** 170625 points

Michael,

I checked this with PRU expert, seems that there is jira ticket created for that issue, LCPD-9737

It appears like the PRU firmwares split packets with VLAN PCP 0-3 into a low priority queue and VLAN PCP 4-7 into a high priority queue. The Linux driver had an error where it was not reading from the higher priority queue (so ingress packets with PCP 4-7 were getting dropped). LCPD team has posted a fix to the Jira that allows the Linux driver to read from the high priority queue. I expect this fix to be implemented in next PSDK 3.04

Regards,
Pavel

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Linux/AM5718: PRU-ICSS Ethernet Linux driver VLAN support