i386/79269: USB ohci da0 plug/unplug causes crashes and lockups.

[Murray Baker]

>Number:         79269
>Category:       i386
>Synopsis:       USB ohci da0 plug/unplug causes crashes and lockups.
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-i386
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Sun Mar 27 04:00:11 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Murray Baker
>Release:        5.3 (also 4.9)
>Organization:
>Environment:
FreeBSD daigomi.baker.lan 5.3-RELEASE FreeBSD 5.3-RELEASE #0: Mon Feb 21 23:45:21 EST 2005     root at daigomi.baker.lan:/usr/src/sys/i386/compile/DAIGOMI  i386

This is a custom kernel. The problem also occurs with standard 5.3 kernel (and also 4.9).
>Description:
      USB mass storage, 1/ 2.5" HDD box with USB2, 2/ USB flash key,
ohci, machine will lock up, reset, or kernel panic when the device is
plugged in or unplugged. This doesn't happen every time, and seems to
happen more on slower machines (socket 7, less often on P///-800). If
no crash or lockup, the USB mass storage (da0) works fine. Problem has
happened on several machines with different chipsets and processors,
and also happens with 4.9.

I suggest that when a USB device is [un]plugged, several cycles of
connect/disconnect/connect occur in rapid succession and the driver
can't handle this. PaidForOs works fine on the same hw.

It is unreasonable to assume that connectors will make/break cleanly.
>How-To-Repeat:
      Repeatedly plug/unplug USB mass storage on ohci USB hw, 4.9 or 5.3.
Try 'wiggling' the connector during [un]plug to provoke the problem.
>Fix:
      
>Release-Note:
>Audit-Trail:
>Unformatted: