I'm trying out a rtw wireless nic and suddenly, it started giving a
lot of TX FIFO underflows:

rtw0 at cardbus0 function 0: Realtek RTL8180 802.11 MAC/BBP
cardbus_mapreg_map called: cardbus0 0
cardbus_mapreg_map: physaddr 40000000
rtw0: interrupting at 11
rtw0: hardware version F
rtw0: SROM version 1.2
rtw0: RF: Philips SA2400A, PA: Philips SA2411
rtw0: analog PHY
rtw0: CS threshold 11
rtw0: Geographic Location USA
rtw0: 802.11 address xx:xx:xx:xx:xx:xx
rtw0: 11b rates: 1Mbps 2Mbps 5.5Mbps 11Mbps
rtw0: link state changed to UP
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 46, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 2, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 50, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 12, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 15, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 17, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 1, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 13, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 19, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 63, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 24, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 36, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 15, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 18, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 46, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 36, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 16, read 0
rtw0: tx fifo underflow
rtw_rxring_fixup: rx-ring expected next 36, read 0
....

Could this be a driver bug ?

-- 
  Rui Paulo			<rpaulo@{NetBSD{,-PT}.org,fnop.net}>