[CentOS] SCSI not settling???

I'm getting a lot of this at boottime:

udev still not settled. Waiting.
udevadm settle - timeout of 0 seconds reached, the event queue contains:
  /sys/module/scsi_wait_scan (11707)

udev still not settled. Waiting.
udevadm settle - timeout of 0 seconds reached, the event queue contains:
  /sys/module/scsi_wait_scan (11709)

udev still not settled. Waiting.
udevadm settle - timeout of 0 seconds reached, the event queue contains:
  /sys/module/scsi_wait_scan (11711)

udev still not settled. Waiting.
udevadm settle - timeout of 0 seconds reached, the event queue contains:
  /sys/module/scsi_wait_scan

It takes a few minutes to boot.

The machine is a Dell PRECISION T5600 with a PERC H310 RAID controller.

-- 
Gé