Re: nforce 550 sata support hotplug??
I have an MCP55 590 board with a JMicron AHCI controller:
# lspci|grep AHCI
03:00.0 SATA controller: JMicron Technologies, Inc. JMicron 20360/20363 AHCI Controller (rev 02)
03:00.1 IDE interface: JMicron Technologies, Inc. JMicron 20360/20363 AHCI Controller (rev 02)
If you also have something like that, then try checking your BIOS for an option like "Onboard SATA/IDE Control Mode" [IDE/AHCI]. If it's there, set it to AHCI and you should be able to use the ahci driver. Oddly, sata_nv is still required on my board as well, so I have both compiled in (but the ahci driver is being used).