ath9k: properly preserve TSF across reset

The beacon code previously reset TSF on every configuration call, as
some of the code was not prepared to properly calculate nexttbtt based
on current TSF.

This patch adds a common function for calculating nexttbtt and moves the
TSF reset to driver start.

This should improve AP mode compatibility with various stations that
expect the TSF to not randomly jump due to hardware resets.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 4798f6ae061e..6a231201c7dc 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -760,6 +760,8 @@ static int ath9k_start(struct ieee80211_hw *hw)
          */
         ath9k_cmn_init_crypto(sc->sc_ah);
 
+        ath9k_hw_reset_tsf(ah);
+
         spin_unlock_bh(&sc->sc_pcu_lock);
 
         mutex_unlock(&sc->mutex);