Maximum iso data length of NRF5340 audio increased

[LandyWang]

Hello,

I am using bis gateway on nrf5340 audio dk to transmit data.

In addition to audio encoded data, I also wanted to send some additional data, so I put these data after the audio encoded data and sent them together, and then I encountered the -EMSGSIZE error.

It seems that the maximum iso data length is 120, if the data length exceeds this size, it will not be transmitted.

Can this maximum length be increased?

[dejans]

Hi,

Do you use nrf5340_audio application? Can you show your changes?

Do you use I2S or USB?

Can you provide a full error log?

Best regards,
Dejan

[LandyWang]

Yes, I use nrf5340_audio application, and I use USB in.

Here are my changes, I increased the data length when sending it.

[audio_system.c]

static void encoder_thread(void *arg1, void *arg2, void *arg3)
{
    ...
    if (sw_codec_cfg.encoder.enabled) {
			/* Send encoded data over IPM */
			//streamctrl_encoded_data_send(encoded_data, encoded_data_size);
			streamctrl_encoded_data_send(my_data, 520);
		}
	STACK_USAGE_PRINT("encoder_thread", &encoder_thread_data);
	}
}

And I added the max data related log to iso_chan_max_data_len function in iso.c.

[iso.c]

static uint16_t iso_chan_max_data_len(const struct bt_iso_chan *chan,
				      uint32_t ts)
{
	...
	/* Update the max_data_len to take the max_controller_data_len into account */
	max_data_len = MIN(max_data_len, max_controller_data_len);
	BT_INFO("Max data len:%d",max_data_len);
	BT_INFO("Max Controller data len:%d",max_controller_data_len);

	return max_data_len;
}

This is the config I added in prj.conf.

CONFIG_BT_ISO_TX_MTU=2048
CONFIG_BT_ISO_RX_MTU=2048

Then this is my error log.

GW [00:00:00.130,798] <inf> bis_gateway: Broadcast source 0x2000bc78 started
GW [00:00:00.131,134] <inf> bis_gateway: Broadcast source 0x2000bc9c started
GW [00:00:11.588,470] <inf> bt_iso: Max data len:120
GW [00:00:11.588,470] <inf> bt_iso: Max Controller data len:1536
GW [00:00:11.588,470] <inf> bt_iso: Cannot send 520 octets, maximum 120
GW [00:00:11.588,470] <wrn> bis_gateway: Failed to send audio data: -122
GW [00:00:11.588,500] <wrn> streamctrl: Problem with sending LE audio data, ret: -122

[dejans]

Hi,

Which NCS version do you use?

Can you show full log?

Best regards,
Dejan

[LandyWang]

The NCS version I use is v2.2.0.

Here is the full log.

SEGGER J-Link V7.88j - Real time terminal output
SEGGER J-Link V9.7, SN=20722384
Process: JLink.exe
*** Booting Zephyr OS build v3.2.99-ncs1 ***


GW [00:00:00.001,922] <dbg> bt_hci_core: bt_hci_driver_register: Registered RPMsg
GW [00:00:00.002,807] <inf> fw_info: 
         nRF5340 Audio nRF5340 Audio DK cpuapp                      
         NCS base version: 2.2.0                            
         Cmake run : Tue Jun 11 09:11:00 2024
GW [00:00:00.002,807] <inf> fw_info: ------- DEBUG BUILD -------
GW [00:00:00.002,838] <inf> fw_info: Compiled for GATEWAY device
GW [00:00:00.002,838] <inf> ble: cw_uicr_get_32:ffffffff
GW [00:00:00.002,838] <inf> ble: cw_uicr_get_16:ffff
GW [00:00:00.002,929] <dbg> bt_hci_core: hci_tx_thread: Started
GW [00:00:00.002,929] <dbg> bt_conn: bt_conn_prepare_events: 
GW [00:00:00.002,960] <dbg> bt_hci_core: hci_tx_thread: Calling k_poll with 2 events
GW [00:00:00.003,112] <dbg> bt_hci_driver: bt_rpmsg_open: 
--- 836 messages dropped ---
GW [00:00:05.020,019] <dbg> bt_hci_driver: bt_rpmsg_rx: RX buf payload:
                                           a4 34 05 00 01 10 00 00  00                      |.4...... .       
GW [00:00:06.019,592] <dbg> bt_hci_core: bt_hci_cmd_create: opcode 0x1001 param_len 0
GW [00:00:06.019,592] <dbg> bt_hci_core: bt_hci_cmd_create: buf 0x2001f0c8
GW [00:00:06.019,622] <dbg> bt_hci_core: bt_hci_cmd_send_sync: buf 0x2001f0c8 opcode 0x1001 len 3
GW [00:00:06.019,653] <dbg> bt_hci_core: process_events: count 4
GW [00:00:06.019,653] <dbg> bt_hci_core: process_events: ev->state 4
GW [00:00:06.019,683] <dbg> bt_hci_core: send_cmd: calling net_buf_get
GW [00:00:06.019,683] <dbg> bt_hci_core: send_cmd: calling sem_take_wait
GW [00:00:06.019,683] <dbg> bt_hci_core: send_cmd: Sending command 0x1001 (buf 0x2001f0c8) to driver
GW [00:00:06.019,714] <dbg> bt_hci_core: bt_send: buf 0x2001f0c8 len 3 type 0
GW [00:00:06.019,714] <dbg> bt_hci_driver: bt_rpmsg_send: buf 0x2001f0c8 type 0 len 3
GW [00:00:06.019,744] <dbg> bt_hci_driver: bt_rpmsg_send: Final HCI buffer:
                                           01 01 10 00                                      |....             
GW [00:00:06.019,775] <dbg> bt_hci_core: process_events: ev->state 0
GW [00:00:06.019,775] <dbg> bt_hci_core: process_events: ev->state 0
GW [00:00:06.019,775] <dbg> bt_hci_core: process_events: ev->state 0
GW [00:00:06.019,805] <dbg> bt_conn: bt_conn_prepare_events: 
GW [00:00:06.019,805] <dbg> bt_conn: conn_prepare_events: Adding conn 0x20002450 to poll list
GW [00:00:06.019,805] <dbg> bt_conn: conn_prepare_events: Adding conn 0x20002518 to poll list
GW [00:00:06.019,836] <dbg> bt_hci_core: hci_tx_thread: Calling k_poll with 4 events
GW [00:00:06.019,897] <dbg> bt_hci_driver: bt_rpmsg_rx: RPMsg data:
                                           04 0e 0c 01 01 10 00 0b  ee 0c 0b e8 07 ee 0c    |........ ....... 
GW [00:00:06.019,897] <dbg> bt_hci_driver: bt_rpmsg_evt_recv: len 12
GW [00:00:06.019,897] <dbg> bt_hci_driver: bt_rpmsg_rx: Calling bt_recv(0x2001f0c8)
GW [00:00:06.019,927] <dbg> bt_hci_core: bt_recv: buf 0x2001f0c8 len 14
GW [00:00:06.019,927] <dbg> bt_hci_core: hci_cmd_complete: opcode 0x1001
GW [00:00:06.019,927] <dbg> bt_hci_core: hci_cmd_done: opcode 0x1001 status 0x00 buf 0x2001f0c8
GW [00:00:06.019,958] <dbg> bt_hci_core: bt_hci_cmd_send_sync: rsp 0x2001f0c8 opcode 0x1001 len 9
GW [00:00:06.020,019] <dbg> bt_hci_driver: bt_rpmsg_rx: RX buf payload:
                                           01 31 00 00 00 0b 00 20  8e                      |.1.....  .       
GW [00:00:07.019,592] <dbg> bt_hci_core: bt_hci_cmd_create: opcode 0x1001 param_len 0
GW [00:00:07.019,622] <dbg> bt_hci_core: bt_hci_cmd_create: buf 0x2001f0c8
GW [00:00:07.019,622] <dbg> bt_hci_core: bt_hci_cmd_send_sync: buf 0x2001f0c8 opcode 0x1001 len 3
GW [00:00:07.019,653] <dbg> bt_hci_core: process_events: count 4
GW [00:00:07.019,653] <dbg> bt_hci_core: process_events: ev->state 4
GW [00:00:07.019,683] <dbg> bt_hci_core: send_cmd: calling net_buf_get
GW [00:00:07.019,683] <dbg> bt_hci_core: send_cmd: calling sem_take_wait
GW [00:00:07.019,683] <dbg> bt_hci_core: send_cmd: Sending command 0x1001 (buf 0x2001f0c8) to driver
GW [00:00:07.019,683] <dbg> bt_hci_core: bt_send: buf 0x2001f0c8 len 3 type 0
GW [00:00:07.019,714] <dbg> bt_hci_driver: bt_rpmsg_send: buf 0x2001f0c8 type 0 len 3
GW [00:00:07.019,714] <dbg> bt_hci_driver: bt_rpmsg_send: Final HCI buffer:
                                           01 01 10 00                                      |....             
GW [00:00:07.019,744] <dbg> bt_hci_core: process_events: ev->state 0
GW [00:00:07.019,775] <dbg> bt_hci_core: process_events: ev->state 0
GW [00:00:07.019,775] <dbg> bt_hci_core: process_events: ev->state 0
GW [00:00:07.019,775] <dbg> bt_conn: bt_conn_prepare_events: 
GW [00:00:07.019,805] <dbg> bt_conn: conn_prepare_events: Adding conn 0x20002450 to poll list
GW [00:00:07.019,805] <dbg> bt_conn: conn_prepare_events: Adding conn 0x20002518 to poll list
GW [00:00:07.019,805] <dbg> bt_hci_core: hci_tx_thread: Calling k_poll with 4 events
GW [00:00:07.019,866] <dbg> bt_hci_driver: bt_rpmsg_rx: RPMsg data:
                                           04 0e 0c 01 01 10 00 0b  ee 0c 0b e8 07 ee 0c    |........ ....... 
GW [00:00:07.019,866] <dbg> bt_hci_driver: bt_rpmsg_evt_recv: len 12
GW [00:00:07.019,897] <dbg> bt_hci_driver: bt_rpmsg_rx: Calling bt_recv(0x2001f0c8)
GW [00:00:07.019,897] <dbg> bt_hci_core: bt_recv: buf 0x2001f0c8 len 14
GW [00:00:07.019,897] <dbg> bt_hci_core: hci_cmd_complete: opcode 0x1001
GW [00:00:07.019,897] <dbg> bt_hci_core: hci_cmd_done: opcode 0x1001 status 0x00 buf 0x2001f0c8
GW [00:00:07.019,927] <dbg> bt_hci_core: bt_hci_cmd_send_sync: rsp 0x2001f0c8 opcode 0x1001 len 9
GW [00:00:07.019,958] <dbg> bt_hci_driver: bt_rpmsg_rx: RX buf payload:
                                           8e 02 03 00 0c 00 00 00  06                      |........ .       
GW [00:00:07.926,574] <inf> bt_iso: Max data len:120
GW [00:00:07.926,574] <inf> bt_iso: Max Controller data len:1536
GW [00:00:07.926,605] <inf> bt_iso: Cannot send 520 octets, maximum 120
GW [00:00:07.926,605] <wrn> bis_gateway: Failed to send audio data: -122
GW [00:00:07.926,605] <wrn> streamctrl: Problem with sending LE audio data, ret: -122
GW [00:00:07.936,584] <inf> bt_iso: Max data len:120
GW [00:00:07.936,584] <inf> bt_iso: Max Controller data len:1536
GW [00:00:07.936,584] <inf> bt_iso: Cannot send 520 octets, maximum 120
GW [00:00:07.936,584] <wrn> bis_gateway: Failed to send audio data: -122
GW [00:00:07.946,563] <inf> bt_iso: Max data len:120
GW [00:00:07.946,563] <inf> bt_iso: Max Controller data len:1536
GW [00:00:07.946,594] <inf> bt_iso: Cannot send 520 octets, maximum 120
GW [00:00:07.946,594] <wrn> bis_gateway: Failed to send audio data: -122
GW [00:00:07.956,573] <inf> bt_iso: Max data len:120
GW [00:00:07.956,573] <inf> bt_iso: Max Controller data len:1536
GW [00:00:07.956,604] <inf> bt_iso: Cannot send 520 octets, maximum 120
GW [00:00:07.956,604] <wrn> bis_gateway: Failed to send audio data: -122