ath5k: use noise calibration from madwifi hal

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>

1 files changed, 1 insertions, 16 deletions

diff --git a/drivers/net/wireless/ath/ath5k/reset.c b/drivers/net/wireless/ath/ath5k/reset.c
index 3dab3d856d7b..62954fc77869 100644
--- a/drivers/net/wireless/ath/ath5k/reset.c
+++ b/drivers/net/wireless/ath/ath5k/reset.c
@@ -1293,7 +1293,7 @@ int ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode,
          * out and/or noise floor calibration might timeout.
          */
         AR5K_REG_ENABLE_BITS(ah, AR5K_PHY_AGCCTL,
-                                AR5K_PHY_AGCCTL_CAL);
+                                AR5K_PHY_AGCCTL_CAL | AR5K_PHY_AGCCTL_NF);
 
         /* At the same time start I/Q calibration for QAM constellation
          * -no need for CCK- */
@@ -1314,21 +1314,6 @@ int ath5k_hw_reset(struct ath5k_hw *ah, enum nl80211_iftype op_mode,
                         channel->center_freq);
         }
 
-        /*
-         * If we run NF calibration before AGC, it always times out.
-         * Binary HAL starts NF and AGC calibration at the same time
-         * and only waits for AGC to finish. Also if AGC or NF cal.
-         * times out, reset doesn't fail on binary HAL. I believe
-         * that's wrong because since rx path is routed to a detector,
-         * if cal. doesn't finish we won't have RX. Sam's HAL for AR5210/5211
-         * enables noise floor calibration after offset calibration and if noise
-         * floor calibration fails, reset fails. I believe that's
-         * a better approach, we just need to find a polling interval
-         * that suits best, even if reset continues we need to make
-         * sure that rx path is ready.
-         */
-        ath5k_hw_noise_floor_calibration(ah, channel->center_freq);
-
         /* Restore antenna mode */
         ath5k_hw_set_antenna_mode(ah, ah->ah_ant_mode);