PROCESSOR-SDK-AM335X: 0x8100 VLAN is not getting received

Art Mecina

Part Number: PROCESSOR-SDK-AM335X
Other Parts Discussed in Thread: AM3352,

Hello Guys,

Our customer is using AM335x based beagle bone. He noticed that CPSW ALE is not passing 0x8100 VLAN header to Linux kernel from Ethernet interface. However, other VLAN headers like 0x9100, 0x88a8 etc. are getting passed from CPSW ALE to Linux kernel and firmware is able to receive all packets.

If he add IP LINK rule or vconfig add <ethernet interface> <VLAN ID> then he is able to receive packet with respective VLAN ID with 0x8100 header too. This is little strange that why "vconfig add" is required to get VLAN packet with 0x8100 header but not required for rest of headers (0x9100, 0x88a8 etc)

Need your help what can be configured in CPSW ALE to make sure they are able to receive all VLAN packets with 0x8100 without adding vconfig add rule?

Thanks in advance!

Art

over 5 years ago

0 Bin Liu over 5 years ago

TI__Guru**** 181376 points

Hi Art,

Which version of the Processor SDK Linux do you use?

0 Art Mecina over 5 years ago in reply to Bin Liu

TI__Genius 16875 points

Hello Bin,

Apologies for the delayed response.

Customer have been using PROCESSOR-SDK-AM335X. It is a beagle bone device using AM3352 CPU module with Marvell Ethernet PHY. And, they are using Linux kernel 4.4.16.

As mentioned limitation is in CPSW ALE which somehow drops packet which specific 0x8100 VLAN header and hence firmware is unable to receive packet (hardware to CPSW driver module). However, rest of headers of VLAN (0x9100, 0x88a8) can be successfully received by firmware. This issue gets resolved when he run "vconfig add <VLAN ID>" and after that firmware is able to receive 0x8100 VLAN header packet. He would like to sniff all VLAN packets (0 to 4095) and hence looking for a solution where he can add rule for all VLAN IDs at one shot.

Please do let me know if you need any more details.

Thanks!

Art

0 Bin Liu over 5 years ago in reply to Art Mecina

TI__Guru**** 181376 points

Hi Art,

Thanks for the update. I have forward this query to our ethernet expert. The response will be posted here soon.

0 Art Mecina over 5 years ago in reply to Bin Liu

TI__Genius 16875 points

Hello Bin,

Any update on this?

Thanks!

Art

0 Art Mecina over 5 years ago in reply to Art Mecina

TI__Genius 16875 points

Hello Bin,

Good day.

Just like to update regarding this request.

Regards,

Art

0 Schuyler Patton over 5 years ago in reply to Art Mecina

TI__Mastermind 41510 points

Hi,

I will check with the development team but to my knowledge for any VLANs you want to receive you will need to add each one specifically with a vlan config command as you mention. If the user wants to sniff the packets have they tried running in the port in promiscuous mode?

Best Regards,

Schuyler

0 Schuyler Patton over 5 years ago in reply to Schuyler Patton

TI__Mastermind 41510 points

Hi,

After discussing with the developer the CPSW understands only 0x8100 and VLAN aware mode is enabled by default (so is vlan filtering). The developer suggests that perhaps looking at setting the interface in promiscuous mode.

Best Regards,

Schuyler

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PROCESSOR-SDK-AM335X: 0x8100 VLAN is not getting received