USB ethernet adapter modeswitch issue

Hi,

i have got a cheap USB ethernet adapter for my ARM SBC running OpenBSD snapshot. If i connect it, it shows up as cdce, but then it automatically detaches and comes up as a usb storage device (it holds the the windows driver ). It does this repeatedly. Can I force somehow OpenBSD to ignore the mass storage device? DMESG below:

uhub2 at uhub1 port 1 configuration 1 interface 0 "Terminus Technology USB2.0 HUB" rev 2.00/1.00 addr 2
cdce0 at uhub2 port 1 configuration 2 interface 0 "wch.cn USB 10/100 LAN" rev 2.00/7.34 addr 3
cdce0: address MA:CA:DD:RE:SS
cdce0 detached
umass0 at uhub2 port 1 configuration 1 interface 0 "wch.cn WCH UDISK_V1.1" rev 2.00/0.31 addr 3
umass0: using SCSI over Bulk-Only
scsibus4 at umass0: 2 targets, initiator 0
cd0 at scsibus4 targ 1 lun 0: <Flash, USB Special Disk, \\205`\\023> removable

it repeats this in ~ every 30 sec.

I have tested it on my x86 laptop running latest stable, it does the same, so it is not a power supply issue.

Thanks for all the hints.

-ext