[SOLVED] exception depending on channel count

[voodoosound]

Hi *,

I am working on an AVB project.
I have defined:

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#define AVB_NUM_CHANNELS_LISTENER 	8

Everythings fine!


Now to my problem.
If I define:

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#define AVB_NUM_CHANNELS_LISTENER 	2

I have an "Illegal Resource Exception" after an undetermined amount of time. The time is never constant.

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-------8<------- from ---- void send_buf_ctl_info(...) ---- out of ---- media_clock_client.xc-------8<-------
  slave {
    buf_ctl :>  buf_;
//	simple_printf("S send_buf_ctl_info: pre tmr  %d %d %d\n",core_id, tmr, buf_);
    tmr :> thiscore_now;                                                       // ILLEGAL RESOURCE EXCEPTION
//	simple_printf("S send_buf_ctl_info: post tmr %d\n", thiscore_now);
    buf_ctl <: thiscore_now;
    buf_ctl <: active;
    buf_ctl <: ptp_ts;
    buf_ctl <: local_ts;
    buf_ctl <: rdptr;
    buf_ctl <: wrptr;
    buf_ctl <: core_id;
  }

-------8<-------------------------------------8<-------

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-------8<------- from ---- void manage_buffer(...) ---- out of ---- media_clock_server.xc-------8<-------

  master {
    buf_ctl <: 0;
//    simple_printf("M manage_buffer: pre tmr %d %d %d \n", tmr,thiscore_now,othercore_now);
    buf_ctl :> othercore_now;
    tmr :> thiscore_now;
//    simple_printf("M manage_buffer: post tmr %d %d %d \n", tmr,thiscore_now,othercore_now);
    buf_ctl :> locked;
    buf_ctl :> presentation_timestamp;    
    buf_ctl :> outgoing_timestamp_local;
    buf_ctl :> rdptr;
    buf_ctl :> wrptr;
    buf_ctl :> server_core_id;
  }

-------8<-------------------------------------8<-------

The tmr variable in MASTER always has a value of 769.
The tmr variable in SLAVE always has a value of 513, but when the exception occurs, it is way higher > 20000, and never the same value.

I don't know where to look anymore.

My suggestion is, that somewhere is a define that causes trouble? I didn't find it yet.
Has anyone any suggestions?

[Andy]

Hi,

What is AVB_NUM_CHANNELS_LISTENER in relation to an unmodified reference design?

Also - what hardware and firmware version are you using?

[voodoosound]

In the reference design sw_avb 5.2.1 it is called:

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#define AVB_NUM_MEDIA_OUTPUTS AVB_DEMO_NUM_CHANNELS

It is a custom hardware, where I am not using any I2S.

[Andy]

It's unusual to get an ILLEGAL_RESOURCE on a timer input, especially after a seemingly random time. What tools version are you using?

One possibility is that you have a stack overflow that is trashing the resource ID. Try removing these unsafe array pragmas from media_clock_server.xc and see if it traps somewhere else:

https://github.com/xcore/sw_avb/blob/ma ... er.xc#L105
https://github.com/xcore/sw_avb/blob/ma ... er.xc#L320

[voodoosound]

Hi,

I am using xTIMEcomposer 12.1.0. Migration to 13.x was to much pain with this project.

To disable the pragmas did not have any visible effect. Same behavior.

Any further ideas?

[segher]

Set a (write) watchpoint on the variable, see where it is
corrupted?

[voodoosound]

Hi again,

I have started to port my project to the 6.1.1 AVB stack now.
But from the start, without only one modification.

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#define AVB_DEMO_NUM_CHANNELS 2

I have a similar issue.
The point where the exception is raised and the exception itself are different and even changing.
But the root of the problem is the same.

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xrun: Program received signal ET_ILLEGAL_INSTRUCTION, Unable to decode instruction.
      [Switching to tile[0] core[4]]

It happend just once and I don know where.

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xrun: Program received signal ET_LOAD_STORE, Memory access exception.
      [Switching to tile[0] core[3]]

at line 126 in avb_1722_listener.xc:

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  // process the audio packet if enabled.
   if (stream_id < MAX_AVB_STREAMS_PER_LISTENER &&
      st.listener_streams[stream_id].active) {...}

or at line 41 in avb_1722_listener_support audio.c:

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int num_channels = stream_info->num_channels;

or at line 96 in media_output_fifo.c:

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  if (s->marker == 0) {...}

It seems to be related to the connection management.
If I do a fast connect on startup, it is stable. If I connect with a controller the exception is raised.
Well it seems, that somehow the stream_info gets corrupted. Has anyone an idea how and where?

[voodoosound]

2 channels in the listener seem to be a critical mass!!!
I have reduced the listener channel count to 3 and it is working untill now.

[voodoosound]

I have found the problem.

the define:

#define AVB_MAX_AUDIO_SAMPLE_RATE 96000

is not allowed to be 48kHz. Otherwise with 2 channels per stream, an exception is raised.