i386/87934: atacontrol attach ata0 causes momentary system freeze on 6.0-RC1; did not do so on 5.4

[Simson L. Garfinkel]

>Number:         87934
>Category:       i386
>Synopsis:       atacontrol attach ata0  causes momentary system freeze on 6.0-RC1; did not do so on 5.4
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Oct 24 17:20:12 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Simson L. Garfinkel
>Release:        6.0-RC1
>Organization:
Harvard University
>Environment:
FreeBSD left.ex.com 6.0-RC1 FreeBSD 6.0-RC1 #0: Sun Oct  9 20:32:57 UTC 2005     root at x64.samsco.home:/usr/obj/usr/src/sys/GENERIC  i386

>Description:
Because of my work, I frequently detach and re-attach ATA drives. Under FreeBSD 5.4 this works like a charm. But on the system on which I am running 6.0-RC1, the system freezes whenever one of the ATA drives that I am trying to attach has a hardware problem. This is roughly 1 out of 5 drives and creates a real hassle.


>How-To-Repeat:
"attacontrol attach ata0" when the drive that is there doesn't work well. The system will freeze for 5 seconds or so, during which time console toggling doesn't work.  This leads me to suspect that interrupts are being disabled for an inappropriately long time.
>Fix:
              
>Release-Note:
>Audit-Trail:
>Unformatted: