MIDI ALSA Disconnect Issue on Nvidia Jetson Orin Nano

Issue Overview

The user is experiencing a problem with MIDI programs on the Nvidia Jetson Orin Nano development board. The issue manifests as follows:

• MIDI programs function only once
• After the initial use, MIDI functionality stops working
• The problem occurs when connecting a MIDI controller directly to the Orin board
• The issue persists even after attempting to use a second computer connected via LAN

The user provided dmesg output after plugging in the MIDI controller, which shows the device being recognized by the system. However, the ALSA tool ‘amidi -d’ only works properly on the first attempt. After interrupting it with Ctrl+C, subsequent attempts to use ‘amidi -d’ fail.

Possible Causes

1. USB Driver Issues: The dmesg output shows the MIDI controller being detected as a USB device. There might be problems with the USB driver handling the device after the initial connection.

2. ALSA Configuration: The ALSA (Advanced Linux Sound Architecture) system might not be properly configured to handle multiple connections or reconnections of the MIDI device.

3. Resource Management: The system may not be releasing resources properly after the first use, preventing subsequent connections.

4. Kernel Module Problems: There could be issues with kernel modules related to MIDI or USB functionality not loading or unloading correctly.

5. Hardware Compatibility: The specific MIDI controller (VMXVJ1 by CODANOVA) might have compatibility issues with the Jetson Orin Nano’s hardware or software stack.

6. Power Management: The USB port or the device might be entering a power-saving mode that prevents proper reconnection.

Troubleshooting Steps, Solutions & Fixes

1. Update System and Drivers:
   Ensure your Jetson Orin Nano is running the latest software and driver versions.

   sudo apt update
   sudo apt upgrade
   

2. Check ALSA Configuration:
   Verify ALSA is correctly configured for MIDI devices.

   cat /proc/asound/cards
   aconnect -l
   

   Look for your MIDI device in the output.

3. Reload ALSA:
   Try reloading the ALSA driver after disconnecting the MIDI device:

   sudo alsa force-reload
   

4. USB Debugging:
   Monitor USB connections in real-time:

   sudo udevadm monitor --environment --udev
   

   Connect and disconnect the MIDI device to see if any errors occur.

5. Check Kernel Modules:
   Ensure necessary modules are loaded:

   lsmod | grep snd
   

   If missing, load required modules:

   sudo modprobe snd-usb-audio
   

6. Test with Different MIDI Software:
   Try alternative MIDI software like aplaymidi or aseqdump to isolate if the issue is specific to amidi.

7. USB Power Management:
   Disable USB autosuspend for the MIDI device:

   echo -1 | sudo tee /sys/bus/usb/devices/1-2.1/power/autosuspend_delay_ms
   

   Replace 1-2.1 with the correct USB path for your device.

8. Kernel Parameter Adjustment:
   Add usbcore.autosuspend=-1 to kernel parameters in /boot/extlinux/extlinux.conf to disable USB autosuspend globally.

9. MIDI Device Permissions:
   Ensure your user has the correct permissions to access the MIDI device:

   sudo usermod -a -G audio $USER
   

   Log out and back in for changes to take effect.

10. Investigate Logs:
    Check system logs for more detailed error messages:

    journalctl -b | grep -i midi
    journalctl -b | grep -i alsa
    

11. Test on Different USB Ports:
    Try connecting the MIDI controller to different USB ports on the Jetson Orin Nano.

12. MIDI Controller Firmware:
    Check if there’s a firmware update available for your VMXVJ1 MIDI controller.

If the issue persists after trying these steps, consider reporting the problem to NVIDIA’s developer forums with detailed logs and the steps you’ve taken. The community or NVIDIA support may provide further assistance or identify if this is a known issue with the Jetson Orin Nano platform.