[ 078/101] mac80211: connect with HT20 if HT40 is not permitted
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2012-10-29 22:01:46
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3.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Johannes Berg <redacted> commit 3a40414f826a8f1096d9b94c4a53ef91b25ba28d upstream. Some changes to fix issues with HT40 APs in Korea and follow-up changes to allow using HT40 even if the local regulatory database disallows it caused issues with iwlwifi (and could cause issues with other devices); iwlwifi firmware would assert if you tried to connect to an AP that has an invalid configuration (e.g. using HT40- on channel 140.) Fix this, while avoiding the "Korean AP" issue by disabling HT40 and advertising HT20 to the AP when connecting. Reported-by: Florian Reitmeir <redacted> Tested-by: Florian Reitmeir <redacted> Signed-off-by: Johannes Berg <redacted> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- net/mac80211/mlme.c | 30 ++++++++++++++++++++---------- 1 file changed, 20 insertions(+), 10 deletions(-)
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c@@ -3065,22 +3065,32 @@ static int ieee80211_prep_connection(str ht_cfreq, ht_oper->primary_chan, cbss->channel->band); ht_oper = NULL; + } else { + channel_type = NL80211_CHAN_HT20; } } - if (ht_oper) { - channel_type = NL80211_CHAN_HT20; + if (ht_oper && sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) { + /* + * cfg80211 already verified that the channel itself can + * be used, but it didn't check that we can do the right + * HT type, so do that here as well. If HT40 isn't allowed + * on this channel, disable 40 MHz operation. + */ - if (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) { - switch (ht_oper->ht_param & - IEEE80211_HT_PARAM_CHA_SEC_OFFSET) { - case IEEE80211_HT_PARAM_CHA_SEC_ABOVE: + switch (ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) { + case IEEE80211_HT_PARAM_CHA_SEC_ABOVE: + if (cbss->channel->flags & IEEE80211_CHAN_NO_HT40PLUS) + ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ; + else channel_type = NL80211_CHAN_HT40PLUS; - break; - case IEEE80211_HT_PARAM_CHA_SEC_BELOW: + break; + case IEEE80211_HT_PARAM_CHA_SEC_BELOW: + if (cbss->channel->flags & IEEE80211_CHAN_NO_HT40MINUS) + ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ; + else channel_type = NL80211_CHAN_HT40MINUS; - break; - } + break; } }