ad0: WARNING - WRITE_DMA recovered from missing interrupt

[C. Kukulies]

ad0: WARNING - WRITE_DMA recovered from missing interrupt
Got this on my Dell Inspiron 8000 while dhclient was running
interactively and wi0: busy bit won't clear was happening.

At the moment with a recently cvsuped -current wi0 on my
gateway (PCI-PCMCIA adapter card) seems to be broken as well as this
everlasting wi0: busy bit won't clear thing which breaks 
WLAN on my Dell Inspiron for weeks now.