A while back I had a problem with 2 scsi disks not working with my 
tekram controller after a reboot,  Manuel Bouyer provided a patch, 
which solved the main problem, but afterwards I noticed console 
messages regarding the drive, weren't always the same
(on 2nd boot, I'd get a line like
sd1: sync (50.00ns offset 15 ) 8 bit 20.000 MB transfers
but nothing corresponding to it on first boot,  Manuel Bouyer provide a 
program to
test the drives speed, I found I'm getting ~ 2 MB speeds, and 7.5 MB on 
second boot.
Well, I went through my adapters setting, found I could get a 
consistent 2 MB/s speed
if I disabled sync negotiation, then I sat on it a while , upgraded to 
2.0.2 and looked
at again.  Let me say, I thinking this easily be a hardware problem, as 
the drives are used, and the power supply could be close to max'ed  -- 
Anyway, recently, I've noticed I can detach, then scan , and get 7.5 
speeds and get the "sync (50.00ns)" among the console messages w/o 
rebooting.  Any thoughts as to what this could be?

Also, is it possible to configure to kernel not to scan the bus?