CXL device cannot be changed from system-ram mode to devdax mode

[sulochb]

Using ndctl-78 on Ubuntu 22.04 with Kernel drivers 6.5rc7, the CXL device always comes up in system-ram.
I would expect it to come up in 'dax' mode until it is reconfigured as 'system-ram' mode.

daxctl list

[
{
"chardev":"dax0.0",
"size":68719476736,
"target_node":1,
"align":2097152,
"mode":"system-ram",
"online_memblocks":504,
"total_memblocks":512
}
]

The 'device-reconfigure' to 'dax' mode fails to change the mode.
#daxctl reconfigure-device dax0.0 --mode=devdax --force
dax0.0: 8 memory sections already offline
libdaxctl: offline_one_memblock: dax0.0: Failed to offline /sys/devices/system/node/node1/memory272/state: Device or resource busy
dax0.0: failed to offline memory: Device or resource busy
error reconfiguring devices: Device or resource busy
reconfigured 0 devices

3. Tried to stop the application using the device, but it does not work:**

fuser -cu /dev/dax0.0

/dev/dax0.0: 206rc(root) 1042m(gdm)

kill -9 206

#fuser -cu /dev/dax0.0
/dev/dax0.0: 206rc(root) 1042m(gdm)