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Subject[063/272] ath9k_hw: do PA offset calibration only on longcal interval
2.6.37-stable review patch.  If anyone has any objections, please let us know.


From: Rajkumar Manoharan <>

commit 811ea256b30b37091b5bbf41517404cf98ab56c1 upstream.

The power detector adc offset calibration has to be done
on 4 minutes interval (longcal * pa_skip_count). But the commit
"ath9k_hw: fix a noise floor calibration related race condition"
makes the PA calibration executed more frequently beased on
nfcal_pending value. Running PAOffset calibration lesser than
longcal interval doesn't help anything and the worse part is that
it causes NF load timeouts and RX deaf conditions.

In a very noisy environment, where the distance b/w AP & station
is ~10 meter and running a downlink udp traffic with frequent
background scan causes "Timeout while waiting for nf to load:
AR_PHY_AGC_CONTROL=0x40d1a" and moves the chip into deaf state.
This issue was originaly reported in Android platform where
the network-manager application does bgscan more frequently
on AR9271 chips. (AR9285 family usb device).

Signed-off-by: Vasanthakumar Thiagarajan <>
Signed-off-by: Rajkumar Manoharan <>
Signed-off-by: John W. Linville <>
Signed-off-by: Greg Kroah-Hartman <>

drivers/net/wireless/ath/ath9k/ar9002_calib.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/ar9002_calib.c
+++ b/drivers/net/wireless/ath/ath9k/ar9002_calib.c
@@ -681,10 +681,6 @@ static bool ar9002_hw_calibrate(struct a

/* Do NF cal only at longer intervals */
if (longcal || nfcal_pending) {
- /* Do periodic PAOffset Cal */
- ar9002_hw_pa_cal(ah, false);
- ar9002_hw_olc_temp_compensation(ah);
* Get the value from the previous NF cal and update
* history buffer.
@@ -699,8 +695,12 @@ static bool ar9002_hw_calibrate(struct a
ath9k_hw_loadnf(ah, ah->curchan);

- if (longcal)
+ if (longcal) {
ath9k_hw_start_nfcal(ah, false);
+ /* Do periodic PAOffset Cal */
+ ar9002_hw_pa_cal(ah, false);
+ ar9002_hw_olc_temp_compensation(ah);
+ }

return iscaldone;

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