kern/43686: EHCI problem: system reboots after attach/extract/attach a pendrive

[jjjesss%gmail.com@localhost]

>Number:         43686
>Category:       kern
>Synopsis:       EHCI problem: system reboots after attach/extract/attach a 
>pendrive
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          support
>Submitter-Id:   net
>Arrival-Date:   Thu Jul 29 21:15:00 +0000 2010
>Originator:     Jes
>Release:        current
>Organization:
none
>Environment:
NetBSD zurich 5.99.37 NetBSD 5.99.37 (MYCONF) #5: Wed Jul 28 10:48:11 CEST 2010 
 root@zurich:/usr/src/sys/arch/amd64/compile/MYCONF amd64

>Description:
My kernel is 5.99.37 amd64. 

When I attach the pendrive:

umass0 at uhub6 port 2 configuration 1 interface 0
umass0: SanDisk MobileMate Micro, rev 2.00/94.07, addr 2
umass0: using SCSI over Bulk-Only
scsibus0 at umass0: 2 targets, 1 lun per target
sd1 at scsibus0 target 0 lun 0: <Generic, STORAGE DEVICE, 9407> disk
removable sd1: fabricating a geometry
sd1: 968 MB, 968 cyl, 64 head, 32 sec, 512 bytes/sect x 1984000 sectors
sd1: fabricating a geometry

and 'usbdevs' shows:

Controller /dev/usb6:
addr 1: high speed, self powered, config 1, EHCI root hub(0x0000),
vendor 0x8086(0x8086), rev 1.00 port 1 powered
 port 2 addr 2: high speed, power 500 mA, config 1, MobileMate
Micro(0xb7b1), SanDisk(0x0781), rev 94.07, serial 000000036215 

All ok until here. I'm able to mount and umount the pendrive the first
time. But if I unmount, extract and attach the pendrive again my system
reboots. In previous versions of current the system simply launched and
error when the pendrive was attached, regarding something about 'ehci'
and the pendrive was not recognized until next system restart. But now
the system reboots in a while after reattach the pendrive. 

After the reboot /var/log/messages shows:

/netbsd: umass0 at uhub6 port 2 configuration 1 interface 0
/netbsd: umass0: SanDisk MobileMate Micro, rev 2.00/94.07, addr 2
/netbsd: umass0: using SCSI over Bulk-Only
/netbsd: scsibus0 at umass0: 2 targets, 1 lun per target
/netbsd: sd2 at scsibus0 target 0 lun 0: <Generic, STORAGE DEVICE,
9407> disk removable  
/netbsd: sd2: fabricating a geometry
/netbsd: sd2: 968 MB, 968 cyl, 64 head, 32 sec, 512 bytes/sect x
1984000 sectors /netbsd: sd2: fabricating a geometry
syslogd[204]: restart
/netbsd: fatal protection fault in supervisor mode
/netbsd: trap type 4 code 0 rip ffffffff8062825b cs 8 rflags 10297 cr2
7f7ffd472c3 0 cpl 6 rsp ffff80005c16e7d0
/netbsd: panic: trap
/netbsd: cpu0: Begin traceback...
/netbsd: uvm_fault(0xffff80005c25a5f0, 0x0, 1) -> e
/netbsd: fatal page fault in supervisor mode
/netbsd: trap type 6 code 0 rip ffffffff802428ef cs 8 rflags 10246 cr2
0 cpl 6 rsp ffff80005c16e390
/netbsd: Skipping crash dump on recursive panic
/netbsd: panic: trap
netbsd: Faulted in mid-traceback; aborting...rebooting...


>How-To-Repeat:
The pendrive I use is really an adapter/reader for a SanDisk micro-sd. So, I 
guess an adapter and a micro-sd is need in order to reproduce the problem.
>Fix: