Using hailo8 in window

[roiyim]

Hi Hailo

Currently, we are working with HailoRT 4.20.0 based on Windows.
After the code execution ends normally, I frequently encounter the following error, though I don’t know the reason:

In the Hailo community, they suggested checking by running hailortcli run. Here is what I found while testing:

1. When I connect to Hailo8 and run hailortcli run, I encounter the above error. (sometimes it works normally)
2. In the error state, when I maintain the connection and run againhailortcli run, I get a buffer len is not valid = 49 error, but it works.
3. On the third execution, it appears to work normally.

My question is about understanding the reason for the errors that occur as described above.

Thanks

[omria]

Hey @roiyim ,

You’re experiencing a common initialization sequence issue with the Hailo-8 device on Windows:

1. First run: Complete failure with multiple errors

   • “FW is not loaded to the device” warning
   • “Buffer len is not valid = 49” error
   • “Read notification failed” error
   • “HAILO_INVALID_OPERATION(6)” error

2. Second run: Partial success with errors

   • Still shows buffer length error but completes inference

3. Third run: Complete success

   • All operations work properly

This behavior points to a delayed device initialization issue where:

• The firmware hasn’t fully loaded when your first command executes
• Device-to-host communication fails due to incomplete initialization
• Buffer validation fails because internal structures aren’t ready
• By the third attempt, the system has stabilized with firmware loaded

Please run the following commands an provide the output to check the problem

hailortcli scan
hailortcli fw-control identify

This non-inference command triggers device detection and firmware checking.

This is a timing/synchronization issue between Windows PCIe device initialization and the Hailo runtime, not a functional problem with the device itself.

One more question : is this after running a reboot after the driver installation ?

[roiyim]

Hi omria

Yes, I rebooted the PC when the installation ended.
What I found in “Window Device Manager” is a device in sleep mode.

According to the Device Manager, it seems that when the device is not in use, power is cut off to that module in power-saving mode.

After unchecking the ‘Allow the computer to turn off this device to save power’ option in the Power Management tab, then the above error disappeared.

Actually, I’m not sure if this is the root cause of the error, but it has been working fine so far.

Thank you for the quick response.