JMicron JMB363 PCIe controler doesn't work

[Wojciech Puchar]

I have motherboard with total 8 SATA ports but seems it's broken as i'm 
having regular server hangs after heavy disk I/O, usually with messages 
about disconnected AHCI device. cables ARE OK.

i bought extra controllers - 2 2-port PCIe based on said chipset.

to make things more strange - 2 of 8 motherboard SATA ports ARE JMB363 
based too!

on motherboard ports are all detected by AHCI driver.

THE same chips on cards are NOT detected as AHCI.
pciconv shows they are in ATA/RAID mode.

But builtin controller BIOS does not allow setting it in AHCI mode.
tried ata/atadisk driver - it doesn't attach disk at all, but just waits 
15 seconds on each port where disk is connected at boot.

Disks ARE properly attached, as cards BIOS shows them up properly.


How can FreeBSD be set up to simply force switching to AHCI mode on that 
chips?