Strange messages from 3w-xxxx

[<gstammw@gmx.net>]

Hello colleagues,

I assume that 3ware-raidcontrollers are being used in a professional or isp
enviorment and not at home so I'm posting this message here and not on the
hardware list.
We're using a lot of 3ware-IDE-Raidcontrollers in several systems and on
most of them I can see strange messages in the system log.
For example
3w-xxxx: scsi0: AEN: WARNING: ATA UDMA upgrade: Port #0.
3w-xxxx: scsi0: AEN: WARNING: ATA UDMA upgrade: Port #0.
3w-xxxx: scsi0: AEN: WARNING: ATA UDMA upgrade: Port #0.
3w-xxxx: scsi0: AEN: WARNING: ATA UDMA upgrade: Port #0.
3w-xxxx: scsi0: AEN: WARNING: ATA UDMA upgrade: Port #1.
3w-xxxx: scsi0: AEN: WARNING: ATA UDMA upgrade: Port #0.
3w-xxxx: scsi0: AEN: WARNING: ATA UDMA upgrade: Port #1.
3w-xxxx: scsi0: AEN: WARNING: ATA UDMA upgrade: Port #0.
But I've also seen some where there was an "ATA UDMA downgrade".

Any ideas what is meant by this message?
It came to my mind that the controller is maybe increasing the udma-speed
from mode 1 to 2 and so on but this shouldn't happen while the system is
actually running but during bootup, right?

Thanks,
Gunther