usbconfig power_off/power_on degrade

[Ruslan Yakovlev]

Hi All
I have internal cardreader. It is established instead of the disk drive. 
After startup dmesg have


ugen1.2: <Generic> at usbus1

umass0: <Generic Mass Storage Device, class 0/0, rev 2.00/1.00, addr 2> 
on usbus1

(probe0:umass-sim0:0:0:0): TEST UNIT READY. CDB: 0 0 0 0 0 0

(probe0:umass-sim0:0:0:0): CAM status: SCSI Status Error

(probe0:umass-sim0:0:0:0): SCSI status: Check Condition

(probe0:umass-sim0:0:0:0): SCSI sense: NOT READY asc:3a,0 (Medium not 
present)

da0 at umass-sim0 bus 0 scbus1 target 0 lun 0

da0: <Generic Storage Device 0.00> Removable Direct Access SCSI-2 device

da0: 40.000MB/s transfers

da0: Attempt to query device size failed: NOT READY, Medium not present


If FreeBSD 8 or 8.1 started without inserted cards I must do
usbconfig -d ugen1.2 power_off
usbconfig -d ugen1.2 power_on
Now I see /dev/da0 and /dev/da0s1 and can mount /dev/da0s1

I update FreeBSD to FreeBSD 8.2-PRERELEASE #28: Sat Dec 4
And after power_off/power_on I can't use cards. Only if I attach card 
before I start FreeBSD I can use card.
After usbconfig -d ugen1.2 power_on I haven't /dev/da0*

dmesg

ugen1.2: <Generic> at usbus1 (disconnected)

umass0: at uhub1, port 5, addr 2 (disconnected)

(da0:umass-sim0:0:0:0): lost device

(da0:umass-sim0:0:0:0): removing device entry

ugen1.2: <Generic> at usbus1

umass0: <Generic Mass Storage Device, class 0/0, rev 2.00/1.00, addr 2> 
on usbus1

da0 at umass-sim0 bus 0 scbus1 target 0 lun 0

da0: <Generic Storage Device 0.00> Removable Direct Access SCSI-2 device

da0: 40.000MB/s transfers

da0: 122MB (250880 512 byte sectors: 64H 32S/T 122C)

umass0: at uhub1, port 5, addr 2 (disconnected)

(da0:umass-sim0:0:0:0): lost device

(da0:umass-sim0:0:0:0): removing device entry