The periodic noise floor calibration is broken on this chip family, because
it keeps triggering a software-filtered noise floor calibration, but never
reads the result before uploading the history buffer value to the hardware.
Fix this with a call to ath9k_hw_getnf(), just like on AR9002.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Acked-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
 
        /* Do NF cal only at longer intervals */
        if (longcal) {
+               /*
+                * Get the value from the previous NF cal and update
+                * history buffer.
+                */
+               ath9k_hw_getnf(ah, chan);
+
                /*
                 * Load the NF from history buffer of the current channel.
                 * NF is slow time-variant, so it is OK to use a historical