Bluetooth: hci0: Frame reassembly failed (-84)

Technical Support
, , ,
1

Hello team,
we have connected the ublox jody w2 evk board to the verdin imx8mp.Using UART interface.
able to detect the node in /dev/ttymxc0 when connected to usb port.
The issue is when i am trying to up the bluetooth it is showing cmd timeout.

Please check the below logs:
Tried with the following different baudrates.
hciattach -n /dev/ttymxc0 any 115200 flow
hciattach -n /dev/ttymxc0 any 3000000 flow
hciattach -n /dev/ttymxc0 any 460800 flow.
hciattach -n /dev/ttymxc0 any 3000000 flow
hciconfig -a
hciconfig hci0 up
Bluetooth: hci0: Frame reassembly failed (-84)
[ 100.010106] Bluetooth: hci0: Frame reassembly failed (-84)
[ 100.015622] Bluetooth: hci0: Frame reassembly failed (-84)
[ 102.014104] Bluetooth: hci0: command 0x1001 tx timeout
[ 104.030104] Bluetooth: hci0: command 0x1009 tx timeout

[ 51.018143] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.023645] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.029142] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.034638] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.040134] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.045629] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.051125] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.056621] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.062114] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.067611] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.067616] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.079672] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.079679] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.091714] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.091721] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.103769] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.109272] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.114767] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.114778] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1

[ 51.126822] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.126828] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.132477] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.138996] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.145560] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.151012] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.157578] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.163025] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.169587] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.175037] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.181600] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.187047] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.193613] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.199058] Bluetooth: hci0: Frame reassembly failed (-84)
[ 51.211084] imx-sdma 30bd0000.dma-controller: restart cyclic channel 1
[ 51.211091] Bluetooth: hci0: Frame reassembly failed (-84)

Any suggestions would be appreciated.

Thanks & regards,
prem0919

2

Hi, I’m the Toradex AI Assistant.

I might make mistakes. Our support team will step in if needed. If I answered your question, please tick the “Solution” checkbox. For follow-up questions to me, please use @ToradexAI in your post.

Did you like my answer? :+1: :-1:

I can see you’re experiencing Bluetooth connectivity issues with your u-blox JODY-W2 EVK connected to the Verdin iMX8MP via UART. The frame reassembly failures and command timeouts suggest communication problems between the Bluetooth module and the host.

Troubleshooting Steps

1. Verify UART Configuration

Based on the Toradex documentation, ensure your UART configuration is correct (1). The Verdin Development Board exposes UART interfaces, and UART_1 is available on a regular 9-pin male D-Sub serial connector through an RS-485 transceiver (1).

2. Use bluetoothctl Instead of hciattach

Starting with BSP version 2.7, bluetoothctl was added to the Linux image and is the recommended tool for Bluetooth operations (2). Instead of using hciattach, try using bluetoothctl:

bluetoothctl

(2)

3. Check Bluetooth Support

Since BSP 2.7b4, Bluetooth support is added to the Toradex pre-built image through kernel driver backports with BlueZ 5 bluetooth software stack (3). Ensure you’re using a compatible BSP version.

4. Hardware Connection Verification

The errors suggest potential hardware communication issues. Verify:

  • Proper UART wiring between the u-blox module and Verdin iMX8MP
  • Correct voltage levels (the Verdin Development Board uses +1.8V TTL signals for UART_1) (1)
  • Flow control connections if required by your u-blox module

5. Alternative UART Interface

Consider testing with different UART interfaces available on your carrier board. The Verdin Development Board has multiple UART options:

  • UART_3 and UART_4 are available via USB Type-C port through FT4232HL converter (1)
  • UART_2 is available on a 9-pin D-Sub connector through RS-232 transceiver (1)

Additional Considerations

The frame reassembly failures (-84) and SDMA controller restarts indicate potential timing or data integrity issues. This could be related to:

  • Incorrect baud rate settings
  • Hardware flow control mismatches
  • Signal integrity problems

Try testing the UART communication first without Bluetooth to ensure basic serial communication works properly between your devices.

Best regards, Toradex AI Assistant.

3

Hi @prem0919!

I’m not familiar with this error, so we might have to investigate it.

The answer given by the Toradex AI seems to be a good starting point. Were you able to test it?

Best regards.