ath9k: Fix noisefloor calibration

commit 696df78509d1f81b651dd98ecdc1aecab616db6b upstream.

The commits,

"ath9k: Fix regression in channelwidth switch at the same channel"
"ath9k: Fix invalid noisefloor reading due to channel update"

attempted to fix noisefloor calibration when a channel switch
happens due to HT20/HT40 bandwidth change. This is causing invalid
readings resulting in messages like:

"ath: phy16: NF[0] (-45) > MAX (-95), correcting to MAX".

This results in an incorrect noise being used initially for reporting
the signal level of received packets, until NF calibration is done
and the history buffer is updated via the ANI timer, which happens
much later.

When a bandwidth change happens, it is appropriate to reset
the internal history data for the channel. Do this correctly in the
reset() routine by checking the "chanmode" variable.

Cc: Rajkumar Manoharan <rmanohar@qca.qualcomm.com>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
[bwh: Backported to 3.2: adjust context, indentation]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Jianguo Wu <wujianguo@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/wireless/ath/ath9k/hw.c b/drivers/net/wireless/ath/ath9k/hw.c
index 20baf70624daab7a9b943e89b948bf15b038a37c..60ed50dd0a393b9445e73dbd0be9993ac73302a0 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/hw.c
+++ b/drivers/net/wireless/ath/ath9k/hw.c
@@ -1628,7 +1628,8 @@ int ath9k_hw_reset(struct ath_hw *ah, struct ath9k_channel *chan,
        if (caldata &&
            (chan->channel != caldata->channel ||
             (chan->channelFlags & ~CHANNEL_CW_INT) !=
-            (caldata->channelFlags & ~CHANNEL_CW_INT))) {
+            (caldata->channelFlags & ~CHANNEL_CW_INT) ||
+            chan->chanmode != caldata->chanmode)) {
                /* Operating channel changed, reset channel calibration data */
                memset(caldata, 0, sizeof(*caldata));
                ath9k_init_nfcal_hist_buffer(ah, chan);

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index b6d1ac9fb326c57346d24070819ffca47ab39f99..ef2605683de7ed84387e5479e66599cc9a568c9b 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -1614,13 +1614,6 @@ static int ath9k_config(struct ieee80211_hw *hw, u32 changed)
                ath_update_survey_stats(sc);
                spin_unlock_irqrestore(&common->cc_lock, flags);
 
-               /*
-                * Preserve the current channel values, before updating
-                * the same channel
-                */
-               if (ah->curchan && (old_pos == pos))
-                       ath9k_hw_getnf(ah, ah->curchan);
-
                ath9k_cmn_update_ichannel(&sc->sc_ah->channels[pos],
                                          curchan, conf->channel_type);