From: Johannes Berg <johannes.berg@xxxxxxxxx>
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.
Cc: stable@xxxxxxxxxxxxxxx [3.6]
Reported-by: Florian Reitmeir <florian@xxxxxxxxxxxx>
Tested-by: Florian Reitmeir <florian@xxxxxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
net/mac80211/mlme.c | 40 ++++++++++++++++++++++++++--------------
1 file changed, 26 insertions(+), 14 deletions(-)
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index fe4b744..3b05952 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -3199,27 +3199,39 @@ static int ieee80211_prep_channel(struct ieee80211_sub_if_data *sdata,
ht_cfreq, ht_oper->primary_chan,
cbss->channel->band);
ht_oper = NULL;
+ } else {
+ channel_type = NL80211_CHAN_HT20;
}
}
- if (ht_oper) {
- const u8 *ht_cap_ie;
- const struct ieee80211_ht_cap *ht_cap;
- u8 chains = 1;
-
- 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;
}
+ }
+
+ if (ht_oper) {
+ const u8 *ht_cap_ie;
+ const struct ieee80211_ht_cap *ht_cap;
+ u8 chains = 1;
ht_cap_ie = cfg80211_find_ie(WLAN_EID_HT_CAPABILITY,
cbss->information_elements,
--
1.7.10.4
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