Rarely we are observing binding issue during setting virtio-pc driver for TG interfaces (run as part of Test or Suite setup):

14:07:11.161 DEBUG reusing ssh: <paramiko.client.SSHClient object at 0x2ddab50>
14:07:11.162 DEBUG Connect peer: ('10.30.51.157', 22)
14:07:11.162 DEBUG Connections: {2994866099658338489: <paramiko.client.SSHClient object at 0x2ddab50>, -7065134172557951845: <paramiko.client.SSHClient object at 0x2dcba90>, 7254523466848074094: <paramiko.client.SSHClient object at 0x2dcb850>}
14:07:11.163 DEBUG [chan 384] Max packet in: 32768 bytes
14:07:11.167 TRACE exec_command on ('10.30.51.157', 22): sudo -S sh -c "echo 1 > /sys/bus/pci/rescan"
14:07:11.281 TRACE exec_command on ('10.30.51.157', 22) took 0.118760108948 seconds
14:07:11.282 TRACE chan_recv/_stderr took 0.000455856323242 seconds
14:07:11.282 TRACE return RC 0
14:07:11.282 TRACE return STDOUT 
14:07:11.282 TRACE return STDERR 
14:07:11.284 DEBUG [chan 385] Max packet in: 32768 bytes
14:07:11.300 TRACE exec_command on ('10.30.51.157', 22): lspci -vmmks 0000:00:09.0
14:07:11.414 TRACE exec_command on ('10.30.51.157', 22) took 0.130872964859 seconds
14:07:11.414 TRACE chan_recv/_stderr took 0.00044584274292 seconds
14:07:11.414 TRACE return RC 0
14:07:11.415 TRACE return STDOUT 
14:07:11.415 TRACE return STDERR 
14:07:11.415 DEBUG reusing ssh: <paramiko.client.SSHClient object at 0x2ddab50>
14:07:11.416 DEBUG Connect peer: ('10.30.51.157', 22)
14:07:11.416 DEBUG Connections: {2994866099658338489: <paramiko.client.SSHClient object at 0x2ddab50>, -7065134172557951845: <paramiko.client.SSHClient object at 0x2dcba90>, 7254523466848074094: <paramiko.client.SSHClient object at 0x2dcb850>}
14:07:11.417 DEBUG [chan 386] Max packet in: 32768 bytes
14:07:11.420 TRACE exec_command on ('10.30.51.157', 22): sudo -S sh -c "echo 0000:00:09.0 > /sys/bus/pci/drivers/virtio-pci/bind"
14:07:11.577 TRACE exec_command on ('10.30.51.157', 22) took 0.160306930542 seconds
14:07:11.577 TRACE chan_recv/_stderr took 0.000383138656616 seconds
14:07:11.578 TRACE return RC 1
14:07:11.578 TRACE return STDOUT 
14:07:11.578 TRACE return STDERR sh: line 0: echo: write error: No such device
14:07:11.580 FAIL 'sh -c "echo 0000:00:09.0 > /sys/bus/pci/drivers/virtio-pci/bind"' failed on '10.30.51.157'
14:07:11.580 DEBUG Traceback (most recent call last):
  File "/w/workspace/csit-vpp-functional-master-centos7-virl/resources/libraries/python/TGSetup.py", line 32, in all_tgs_set_interface_default_driver
    InterfaceUtil.tg_set_interfaces_default_driver(node)
  File "/w/workspace/csit-vpp-functional-master-centos7-virl/resources/libraries/python/InterfaceUtil.py", line 423, in tg_set_interfaces_default_driver
    interface['driver'])
  File "/w/workspace/csit-vpp-functional-master-centos7-virl/resources/libraries/python/InterfaceUtil.py", line 322, in tg_set_interface_driver
    .format(cmd, node['host']))

We tried to fix it by forcing pci inerfaces rescan but it didn't help. The problem is that even the port is already binded to the driver the corresponding information is not returned (see red highlighted text) so current driver is considered to be None and script is trying to bind the interface to required driver (yellow highlighted text).

Full log file is attached.