Configuring i.MX 8M Plus EVK as Milan Listener

[praveen_yaramada]

I am currently working through the demo outlined in Chapter 9 of the [https://www.nxp.com/docs/en/user-guide/GENAVBTSNUG.pdf]. The goal is to set up the i.MX 8M Plus EVK as a Milan listener. My setup involves an AVB switch and a MacBook Pro equipped with an AVB adapter, acting as the Talker.

While the Hive system successfully recognizes the EVK as a media device and the output stream appears active, I am encountering a challenge with establishing a route. The Talker is configured to operate at 48KHz with a 2-channel setup. Hive reports the route could not be established. The contents of /var/log/avb_media_app.log shows this:

NXP's GenAVB ALSA reference application

binding params file name: /etc/genavb/milan_binding_params.nvram

Read EntityID 00049f0852680000 Listener unique ID 0 Talker entity ID f5d48870de1e8000 Talker unique ID 0 Controller entity ID003093190b820082 Started 1

Sent binding parameters: EntityID 00049f0852680000 Listener unique ID 0 Talker entity ID f5d48870de1e8000 Talker unique ID 0 Controller entity ID003093190b820082 Started 1

wait for new stream...

GENAVB_MSG_MEDIA_STACK_BIND: Controller (f5d48870de1e0000) bound listener stream (00049f0852680000, 0, STARTED) to talker stream (f5d48870de1e8000, 0)

update /etc/genavb/milan_binding_params.nvram with entry: EntityID 00049f0852680000 Listener unique ID 0 Talker entity ID f5d48870de1e8000 Talker unique ID 0 Controller entity IDf5d48870de1e0000 Started 1

GENAVB_MSG_MEDIA_STACK_CONNECT

stream ID: 003093190b820005

mode: AVDECC LISTENER

Configured AVB batch size (bytes): 480

alsa(0xaaaace875870) buffer size 2040, period size 24

Plug PCM: Hardware PCM card 2 'wm8960-audio' device 0 subdevice 0

Its setup is:

  stream       : PLAYBACK

  access       : MMAP_INTERLEAVED

  format       : S32_LE

  subformat    : STD

  channels     : 2

  rate         : 48000

  exact rate   : 48000 (48000/1)

  msbits       : 32

  buffer_size  : 2040

  period_size  : 24

  period_time  : 500

  tstamp_mode  : NONE

  tstamp_type  : MONOTONIC

  period_step  : 1

  avail_min    : 24

  period_event : 1

  start_threshold  : 1

  stop_threshold   : 2040

  silence_threshold: 0

  silence_size : 0

  boundary     : 9187343239835811840

  appl_ptr     : 0

  hw_ptr       : 0

Starting listener loop, non-blocking mode

GENAVB_MSG_MEDIA_STACK_DISCONNECT

Loop function exited upon avdecc disconnect

Build is made per the EVK's User Guide: `DISTRO=nxp-real-time-edge MACHINE=imx8mp-lpddr4-evk`

I have made the following configurations:

• Modified the /etc/genavb/config file to set GENAVB_TSN_CONFIG=2.
• Adjusted the /etc/genavb/config_avb file to PROFILE=21.
• Updated the U-Boot env variable setenv fdtfile imx8mp-evk-avb.dtb.

I would greatly appreciate any guidance or recommendations you might have to resolve this routing issue and successfully complete the demo setup as described.

[praveen_yaramada]

Update

I've delved deeper into the logs and implementation and would like to share these findings. Hoping to find a resolution for Milan Audio demo not working. 

1. Log Analysis: Examined the logs located in /var/log/avb.log. The log files reveal additional details about the stream negotiation process and the state-machine behavior of acp_milan_listener. Enclosed the log file for your review.
   Here is a short excerpt:
   

   entity(0xffff80001cf0) listener sink (0) : event ACMP_LISTENER_SINK_SM_EVENT_RCV_PROBE_TX_RESP, state from ACMP_LISTENER_SINK_SM_STATE_PRB_W_RESP to ACMP_LISTENER_SINK_SM_STATE_SETTLED_NO_RSV
   avdecc(0xffff80000b70) port(0) listener declaration LISTENER_FAILED for stream_id(003093190b820005)
   avdecc(0xffff80000b70) port(0) Received listener status NO_TALKER for stream_id(003093190b820005)

2. Version mismatch: A potential source code mismatch has caught my attention. The GenAVB currently in use is version 5.10, whereas the build is on kernel version 6.1. I see a possible candidate here (https://github.com/NXP/GenAVB_TSN/tree/6_1).
   I am contemplating whether updating to AVB implementation aligned with the kernel 6.1 could potentially rectify the issue I'm experiencing. Before proceeding, I would highly appreciate any insights or recommendations from the community or NXP support team.

Thank you for your continued support and assistance.

[Zhiming_Liu · Accepted solution]

Hi @praveen_yaramada 

The different version could be one reason for this issue.If you are using L6.1.y kernel ,you can try to use 6.1 GENAVB.

Best Regards

Zhiming