Subject: Question about the bha driver and devices attached after boot time.
To: None <>
From: Brian Buhrow <>
List: tech-kern
Date: 10/30/1998 12:08:37
	Hello.  I have a Buslogic card on a 486 system running the bha driver.
When I first boot the machine I get messages like the following:

bha1 at pci0 dev 20 function 0: BusLogic 9xxC SCSI
bha1: interrupting at irq 11
bha1: model BT-946C, firmware 4.25J
bha1: sync, parity
bha1 targ 0: sync, offset 15, period 100nsec
bha1 targ 1: sync, offset 15, period 200nsec
scsibus0 at bha1: 8 targets

However, if I boot a machine and run for a while and decide to attach some
extra SCSI devices without rebooting, I only get the following when I do a

sd3: 2050MB, 3907 cyl, 10 head, 107 sec, 512 bytes/sect x 4199760 sectors
uk0 at scsibus0 targ 6 lun 0: <SONY, CD-R   CDU920S, 2.0c> SCSI2 4/worm removable
uk0: unknown device

My question is:
When I do a scsireprobe, is the sync speed being negotiated at the same
time?  There's no indication that this is true, and, indeed, my cdrom
burner doesn't work very well when I attach it and reprobe, but works fine
when I attach it and reboot.  My suspicion is that additional devices,
which are attached after the machine is booted and running, are not getting
any signal to negotiate synchronous operations when the sCSI bus is
reprobed.  So, they're running in async mode until a reboot is done.  Is
this correct?  If it is correct, can one force a renegotiation of the
communication speed of the devices without rebooting?