canIoCtlInit failes with canERR_PARAM (-1) on Kvaser Leaf Light v2 for Linux

[kyle-lawson-innio]

Describe the bug

Creating a bus fails during initialization. I'm using the Kvaser backend under Linux with a Kvaser Leaf Light v2. Using the Leaf Light v2 on Windows the same function is successful

import can

bus = can.Bus(
    interface="kvaser",
    channel=0,
    bitrate=500000,
)

raises

can.interfaces.kvaser.canlib.CANLIBOperationError:
Function canIoCtl failed - Error in parameter [Error Code -1]

To Reproduce

1. Attach a Kvaser Leaf Light dongle (I used the Leaf V2)
2. initialize the bus with can.interface.Bus(interface='kvaser', channel=0, bitrate=500000)

Expected behavior

The bus will initialize without any errors thrown

Additional context

OS and version: Fedora 44
Python version: 3.14.6
python-can version: 4.6.1
python-can interface/s (if applicable): Kvaser Leaf Light v2 and Kvaser Linux SDK 5.52

Investigateion

I verified that...

• can.detect_available_configs() correctly discovers the device.
• canOpenChannel() succeeds
• the Channel can be opened directly using the CANlib bindings
• the failure occurs during the initialization of canIoCtlInit() calls in KbaserBus.__init__()

The failure occurs on canIOCTL_SET_LOCAL_TXACK or specifically...

canIoCtlInit(
    self._read_handle,
    canstat.canIOCTL_SET_LOCAL_TXACK,
    ctypes.byref(ctypes.c_byte(local_echo)),
    1,
)

Work-Around

commenting out this section of code allows me to continue initializing the bus and my program runs smoothly.

Potentially related Issue

#2051

[kyle-lawson-innio]

Here is my more formal work-around/suggestion for can/interfaces/kvaser/canlib.py

        # enable canMSG_LOCAL_TXACK flag in received messages

        try:
            canIoCtlInit(
                self._read_handle,
                canstat.canIOCTL_SET_LOCAL_TXACK,
                ctypes.byref(ctypes.c_byte(local_echo)),
                1,
            )
        except CANLIBOperationError as exc:
            # Some Linux CANlib/device combinations do not support
            # canIOCTL_SET_LOCAL_TXACK and return canERR_PARAM (-1).
            # Continue without TXACK support.
            if exc.error_code != canstat.canERR_PARAM:
                raise

            log.debug(
                "canIOCTL_SET_LOCAL_TXACK not supported by this device/CANlib; "
                "continuing without local TXACK."
            )