Commit 172710bf authored by Ben Greear's avatar Ben Greear Committed by John W. Linville
Browse files

mac80211: Warn users if HT fails because of freq mismatch. 



I have a netgear WNDR3700 that appears to have an off-by-four
bug in how it fills out the hti->control_chan (I configure the
AP to channel 11, it reports 15 as control_chan).

Poke a message into the kernel logs to give users a
clue as to why they are not getting the expected
channel-type or rate.

Signed-off-by: default avatarBen Greear <greearb@candelatech.com>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent 0fa025f0

net/mac80211/mlme.c

+22 −4
Original line number Diff line number Diff line
@@ -161,6 +161,7 @@ static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata, 
	struct ieee80211_supported_band *sband;

	struct sta_info *sta;

	u32 changed = 0;

	int hti_cfreq;

	u16 ht_opmode;

	bool enable_ht = true;

	enum nl80211_channel_type prev_chantype;
@@ -174,10 +175,27 @@ static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata, 
	if (!sband->ht_cap.ht_supported)

		enable_ht = false;



	if (enable_ht) {

		hti_cfreq = ieee80211_channel_to_frequency(hti->control_chan,

							   sband->band);

		/* check that channel matches the right operating channel */

	if (local->hw.conf.channel->center_freq !=

	    ieee80211_channel_to_frequency(hti->control_chan, sband->band))

		if (local->hw.conf.channel->center_freq != hti_cfreq) {

			/* Some APs mess this up, evidently.

			 * Netgear WNDR3700 sometimes reports 4 higher than

			 * the actual channel, for instance.

			 */

			printk(KERN_DEBUG

			       "%s: Wrong control channel in association"

			       " response: configured center-freq: %d"

			       " hti-cfreq: %d  hti->control_chan: %d"

			       " band: %d.  Disabling HT.\n",

			       sdata->name,

			       local->hw.conf.channel->center_freq,

			       hti_cfreq, hti->control_chan,

			       sband->band);

			enable_ht = false;

		}

	}



	if (enable_ht) {

		channel_type = NL80211_CHAN_HT20;