usb/88966: kldunload ucom.ko returns "Device busy" error.

[Dr. Gary E. RAFE]

>Number:         88966
>Category:       usb
>Synopsis:       kldunload ucom.ko returns "Device busy" error.
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-usb
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Nov 14 02:40:14 GMT 2005
>Closed-Date:
>Last-Modified:
>Originator:     Dr. Gary E. RAFE
>Release:        5.4-RELEASE
>Organization:
Rafe & Rouillard Group LLC
>Environment:
FreeBSD tsp6100a.nonet 5.4-RELEASE FreeBSD 5.4-RELEASE #1: Mon May 23 14:26:14 EDT 2005     root at tsp6100a:/usr/src/sys/i386/compile/TSP6100B  i386
>Description:
Attempting to communicate with a Palm m515 device
via the attached USB connection.

As root, "kldload ucom.ko", "kldload uvisior.ko"
allows access to /dev/ucom0 when the Palm device
is in "hot sync" mode.

After hot-sync is complete,
"kldunload uvisor.ko" releases the named kernel module.
"kldunload ucom.ko", however, returns the message
"Device busy", and the module is not removed.

Attempts to remove the kernel module "usb.ko"
prior to APM suspend fails with "Device busy" error.

USB sub-system is unusable following APM resume,
requiring warm re-boot.

Hardware is Toshiba Satellite Pro 6100, USB 1.1 devices.
>How-To-Repeat:
# Following system startup:

kldload usb.ko
kldload ucom.ko
kldload uvisor.ko
# ...
kldunload uvisor.ko
kldunload ucom.ko
kldunload usb.ko

# Modules usb.ko & ucom.ko still loaded here...
>Fix:
No known fix.
>Release-Note:
>Audit-Trail:
>Unformatted: