CM4 connection issues

martin181818

Dear Community

We are currently experiencing several issues related to the CM4 camera and device detection in our lab environment. Below is a summary of the problems we've encountered:

Renesas Firmware Module Missing:
The firmware fails to load as there is no external module available to enable it. We could not locate any hci_usb_renesas.ko or hci_pci_renesas.ko modules.
Bus Disappearance After Power Loss:
When the camera power is disconnected without proper shutdown, USB buses 002 and 003 disappear. Running dmesg | grep renesas indicates that the Renesas module failed to load.
Persistent Failure After Reboot:
Even after multiple reboots, the system cannot recover or re-enable the controller manually.
Multiple Kernel Versions in Use:
We are testing across various kernel versions (6.6.51 / 6.6.74 / 6.6.81) but the issue persists.
USB Speed Shifts:
We observed frequent transitions from USB speed 1.1 to 2.1, as shown in the attached screenshots.
DepthAI Version Impact:
Updating DepthAI from version 2.28.0.0 to 2.30.0.0 resolves the dai.Device not found issue.
Inconsistent Bus Detection with Movidius:
Often only bus 003 is visible when using Movidius devices, while bus 002 is not — we’re unsure what this behavior implies.

Could you please assist or advise on how to address these issues ?

jakaskerl

martin181818
Can you try following this thread - https://discuss.luxonis.com/d/5966-using-luxonis-preped-rpi-os-images-v10/2

Thanks,
Jaka

Stefano

Hello everyone,
I'm having a similar problem:

`(venv) pi@luxonis:/usr/bin/user $ lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 002: ID 03e7:2485 Intel Movidius MyriadX
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

(venv) pi@luxonis:/usr/bin/user $ python
Python 3.11.2 (main, Mar 13 2023, 12:18:29) [GCC 12.2.0] on linux
import depthai as dai
dai.Device.getAllAvailableDevices()
[2025-08-18 12:03:04.554] [depthai] [warning] skipping X_LINK_UNBOOTED device having name "2.1"
[]`

Following the suggestions on the link I get:
(venv) pi@luxonis:/usr/bin/user $ echo -n 0000:01:00.0 | sudo tee /sys/bus/pci/drivers/xhci-pci-renesas/bind tee: /sys/bus/pci/drivers/xhci-pci-renesas/bind: No such file or directory

'(venv) pi@luxonis:/usr/bin/user$ ls /sys/bus/pci/drivers/
8250_pericom cn10k_rng dwc3-haps exar_serial nvme pcieport rp1 serial xhci_hcd'

Do you have any info on why the renesas module does not seem to be present?

Also, was this the actual solution of the original problem? because from the discussion linked above it seems like you are still checking the core cause.

Thank you

jakaskerl

Stefano
In your case the device seems to be detected correctly so it is not the same issue. Are you on CM4 as well? Which image are you using?

Thanks,
Jaka

Stefano

jakaskerl

I just used 'sudo apt update && sudo apt -y upgrade'

now when i call lsusb it returns:
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 003 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

I tried again with the suggestion, but it seems the resource is busy. I rebooted the camera, but I keep having the issue.

echo -n 0000:01:00.0 | sudo tee /sys/bus/pci/drivers/xhci-pci-renesas/bind
0000:01:00.0tee: /sys/bus/pci/drivers/xhci-pci-renesas/bind: Device or resource busy

dai.Device.getAllAvailableDevices() keeps returning []

do you have any idea?

Thank you

jakaskerl

Stefano
https://drive.google.com/drive/u/1/folders/1O50jPpGj_82jkAokdrsG--k9OBQfMXK5 I think the latest image should have this fixed cc @OskarSonc

Thanks
Jaka

martin181818

jakaskerl

Thank you for your help.
I downloaded version V11 of the OAK image, and the Renesas loading issue is still present.

I found that this is a concurrency problem between the moment the xhci-pci module (which includes the Renesas driver) actually starts and requests the file K2026.mem in /lib/firmware/renesas/, and the moment when this file is actually available. If the file is not found, the initialization fails and does not recover.

Starting from this situation, which applies to all kernel versions, the following manual command:
sudo ln -sf renesas/K2026.mem /lib/firmware/renesas_usb_fw.mem

creates a symbolic link between these two files. Then the command:
echo -n 0000:01:00.0 | sudo tee /sys/bus/pci/drivers/xhci-pci-renesas/bind

is executed to force the reinitialization of the search.

After this procedure, Bus 002 and Bus 003 are correctly detected, and the device can be identified using dai.Device.getAllAvailableDevices().

If a normal reboot is performed, or the Ethernet cable is disconnected, the device no longer detects Bus 002 and 003. To detect them again, it is sufficient to run the second command:
echo -n 0000:01:00.0 | sudo tee /sys/bus/pci/drivers/xhci-pci-renesas/bind

Is there a way to verify that the installed version of the image is indeed the correct one?

Thank you

Stefano

jakaskerl
I'm having some problems in flashing the new image.
I start the flashing procedure, and after a while it freezes, one time at 96%, another one at 19%.
Any suggestion about this problem?

Also, did you manage to complete your test to check if the latest image actually fix the original issue of the post?

Thank you

OskarSonc

Hey @martin181818, thanks a lot for digging into this and sharing the details.

When I tested the device I didn’t see the issue you describe, but I’ll run some more tests on my side to double-check.
Can you let me know if you’re using a PoE CM4 device or a non-PoE version? That will help narrow it down.

martin181818

OskarSonc

I am using the PoE version of CM4.
Thank you.

OskarSonc

Stefano
Are you using Raspberry Pi Imager or balenaEtcher?
It's normal that it takes a lot of time, since it's USB 2.0 connection…

We are working on it. Looks like the problem is only for PoE device…
For now these two commands seem to resolve it:
sudo ln -sf renesas/K2026.mem /lib/firmware/renesas_usb_fw.mem

echo -n 0000:01:00.0 | sudo tee /sys/bus/pci/drivers/xhci-pci-renesas/bind

Stefano

OskarSonc
I tried with both PiImager and balenaEtcher, the flashing freezed after a while.
I left the process go on for a couple of days before stopping, so I don't think it to be just slow.

Let me know about the PoE actual solution as soon as possible please.

Thank you

OskarSonc

Hey @Stefano ,

Can you double-check that the switch is set to ENABLE and that you followed the steps from the tutorial:

https://docs.luxonis.com/hardware/platform/deploy/to-rpi#Deploy%20with%20Raspberry%20Pi-Flashing%20an%20image%20to%20the%20eMMC?

Also, please try a different USB cable/port if possible.

For the PoE issue, yes I will let you know…

Best
Oskar