The rawhide kernel scans the SCSI bus asynchronously. The initrd doesn't wait
for the scan to complete, after loading a host adapter module. It should,
because otherwise the SCSI drives aren't guaranteed to be present by the time
the final 'mkblkdevs' run happens. And my PS3 doesn't boot...

One way of doing this is to load the 'scan_wait_scan.ko' module. Although that
seems a bit weird to me; I would have thought we could just provide a file in
sysfs where reading or writing would have the same effect.