corrupted data when manipulating MTU at runtime

[bmegli]

Sometimes when manipulating MTU data is corrupted afterwards

[bmegli]

Related to #24

[bmegli]

Current workaround if problem happens is to restart the node

[bmegli]

Another workaround is not to change MTU but in some scenarios it is necessary

[bmegli]

It looks like device remembers MTU

I can see it in output

[ INFO] [1696942328.057653062]:     Network mtu          = 9000

And it is value set last time when launching node

[bmegli]

Above comes from

  if (implemented_features_["GevSCPSPacketSize"])
    ROS_INFO("    Network mtu          = %lu", aravis::device::feature::get_integer(p_device_, "GevSCPSPacketSize"));

Which confirms it's readout from device

[bmegli]

Logic on dynamic reconfigure change

 if (changed_mtu)
  {
    if (implemented_features_["GevSCPSPacketSize"])
    {
      ROS_INFO("Set mtu = %d", config.mtu);
      aravis::device::feature::set_integer(p_device_, "GevSCPSPacketSize", config.mtu);
      ros::Duration(1.0).sleep();
      config.mtu = aravis::device::feature::get_integer(p_device_, "GevSCPSPacketSize");
      ROS_INFO("Get mtu = %d", config.mtu);
    }
    else
      ROS_INFO("Camera does not support mtu (i.e. GevSCPSPacketSize).");
  }

[bmegli]

It also looks like apart from dynamic reconfigure MTU there is also initially setup value from ROS parameter

  pnh.param<int>("mtu", config_.mtu, config_.mtu);

This value seems to be happily ignored later (overwritten by dynamic reconfigure default?)

At the same time device may have different MTU from above 2 values.

What a mess.

[bmegli]

Reproducible

1. From cold booted MotionCam3D and ROS PC
2. Modify MTU on ROS PC OS side

sudo ifconfig enp60s0 mtu 9000

3. Start ROS driver

4. Wait until camera initializes

5. Modify MTU on MotionCam3D ROS driver

rosrun rqt_reconfigure rqt_reconfigure
# set to matching 9000

6. Request depth and raw image

Restart of ROS driver fixes the problem

[bmegli]

OS MTU doesn't need to be changed after starting the driver for the problem to manifest

Updating above

[bmegli]

After fixing setting up MTU from rosparam in:

• 24

I can now initialize with selected MTU from cold booted MotionCam3D and ROS without corrupted data

[bmegli]

Now that MTU was removed from dynamic reconfigure.

Setting MTU using launchtime GenICam GevSCPSPacketSize will not cause problem.

Maybe problem can be reproduced by service call GenICam setup at runtime

[bmegli]

The call would be:

rosservice call /camera/set_integer_feature_value "feature: 'GevSCPSPacketSize'
value: 9000"

Needs retesting scenario

[bmegli]

Reproducible (new way)

1. From cold booted MotionCam3D and ROS PC
2. Modify MTU on ROS PC OS side

sudo ifconfig enp60s0 mtu 9000

3. Start ROS driver

4. Wait until camera initializes

5. Modify MTU on MotionCam3D ROS driver using service

rosservice call /camera/set_integer_feature_value "feature: 'GevSCPSPacketSize'
value: 9000"

6. Request depth and raw image

[bmegli]

Workarounds

Set MTU at launchtime

Using GevSCPSPacketSize

This is not affected by bug.

Restart node

If getting corrupted data after service call changing MTU restarting node will fix the problem

Keep changing MTU

This worked with dynamic reconfigure, probably will also work with service

[bmegli]

Note:

• we didn't get to the root cause
• but we don't mind
  • as we implemented working way to set it (at init time)
  • as scenario with manipulating MTU at runtime is obscure
  • and there are 3 workarounds