According to my investigation,this problem is NOT caused by the driver but somewhere else(the boot loader and so on).
Reason:
- The iwm driver on GhostBSD via UEFI boot -> works well
- The similar(almost same logic) driver on Haiku via UEFI boot -> won’t work
- The similar(almost same logic) driver on Haiku via BIOS boot -> works well
So,I will check the boot process first.
It maybe hard to fix although,I will try that!