This updates ath5k to calibrate the noise floor similar to the
way it is done in the madwifi hal and ath9k. Of note:
- we start NF measurement at the same time as AGC calibration,
but do not actually read the value until the periodic (long)
calibration
- we keep a history of the last few values read and write the
median back to the hardware for CCA
- we do not complain if NF calibration isn't complete, instead
we keep the last read value.
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Acked-by: Nick Kossifidis <mickflemm@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
e5e2647fd6