phantom device disconnects

[Andriy Gapon]

Since yesterday I am getting message like the following at random intervals:
ugen1.3: <Unknown> at usbus1 (disconnected)
ugen1.3: <Unknown> at usbus1 (disconnected)
ugen1.3: <Unknown> at usbus1 (disconnected)

There are not matching messages about any connected device and usbconfig,
obviously, knows nothing about ugen1.3:
ugen6.1: <OHCI root HUB ATI> at usbus6, cfg=0 md=HOST spd=FULL (12Mbps) pwr=SAVE
(0mA)
ugen5.1: <EHCI root HUB ATI> at usbus5, cfg=0 md=HOST spd=HIGH (480Mbps)
pwr=SAVE (0mA)
ugen4.1: <OHCI root HUB ATI> at usbus4, cfg=0 md=HOST spd=FULL (12Mbps) pwr=SAVE
(0mA)
ugen3.1: <OHCI root HUB ATI> at usbus3, cfg=0 md=HOST spd=FULL (12Mbps) pwr=SAVE
(0mA)
ugen2.1: <EHCI root HUB ATI> at usbus2, cfg=0 md=HOST spd=HIGH (480Mbps)
pwr=SAVE (0mA)
ugen1.1: <OHCI root HUB ATI> at usbus1, cfg=0 md=HOST spd=FULL (12Mbps) pwr=SAVE
(0mA)
ugen0.1: <OHCI root HUB ATI> at usbus0, cfg=0 md=HOST spd=FULL (12Mbps) pwr=SAVE
(0mA)
ugen1.2: <USB Receiver Logitech> at usbus1, cfg=0 md=HOST spd=FULL (12Mbps)
pwr=ON (98mA)
ugen2.2: <product 0x2514 vendor 0x0424> at usbus2, cfg=0 md=HOST spd=HIGH
(480Mbps) pwr=SAVE (2mA)

Seems like this is caused by flaky hardware?  Or something else?

Is there a way to stop the spam?
Should we be reporting diconnects for unattached ports at all?

Thanks!
-- 
Andriy Gapon