From: Johannes Berg <johannes.berg@xxxxxxxxx>
Changing the channel type during operation is
confusing to some drivers and will be hard to
handle in multi-channel scenarios. Instead of
changing the channel, set it to the right HT
channel before authenticating/associating and
don't change it -- just update the 20/40 MHz
restrictions in rate control as needed when
changed by the AP.
This also fixes a problem that Paul missed in
his fix for the "regulatory makes us deaf"
issue -- when we couldn't use 40 MHz we still
associated saying we were using 40 MHz, which
could in similarly broken APs make us never
even connect successfully.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
Documentation/networking/mac80211-auth-assoc-deauth.txt | 10
net/mac80211/ht.c | 9
net/mac80211/ieee80211_i.h | 10
net/mac80211/mlme.c | 225 +++++++---------
4 files changed, 117 insertions(+), 137 deletions(-)
--- a/net/mac80211/ieee80211_i.h 2012-03-15 15:50:35.000000000 +0100
+++ b/net/mac80211/ieee80211_i.h 2012-03-15 16:27:56.000000000 +0100
@@ -378,6 +378,7 @@ enum ieee80211_sta_flags {
IEEE80211_STA_UAPSD_ENABLED = BIT(7),
IEEE80211_STA_NULLFUNC_ACKED = BIT(8),
IEEE80211_STA_RESET_SIGNAL_AVE = BIT(9),
+ IEEE80211_STA_DISABLE_40MHZ = BIT(10),
};
struct ieee80211_mgd_auth_data {
@@ -497,6 +498,8 @@ struct ieee80211_if_managed {
int rssi_min_thold, rssi_max_thold;
int last_ave_beacon_signal;
+ enum nl80211_channel_type tx_chantype;
+
struct ieee80211_ht_cap ht_capa; /* configured ht-cap over-rides */
struct ieee80211_ht_cap ht_capa_mask; /* Valid parts of ht_capa */
};
@@ -653,12 +656,6 @@ struct ieee80211_sub_if_data {
char name[IFNAMSIZ];
- /*
- * keep track of whether the HT opmode (stored in
- * vif.bss_info.ht_operation_mode) is valid.
- */
- bool ht_opmode_valid;
-
/* to detect idle changes */
bool old_idle;
@@ -1300,7 +1297,6 @@ netdev_tx_t ieee80211_subif_start_xmit(s
struct net_device *dev);
/* HT */
-bool ieee80111_cfg_override_disables_ht40(struct ieee80211_sub_if_data *sdata);
void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
struct ieee80211_sta_ht_cap *ht_cap);
void ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
--- a/net/mac80211/mlme.c 2012-03-15 15:50:35.000000000 +0100
+++ b/net/mac80211/mlme.c 2012-03-15 16:27:56.000000000 +0100
@@ -171,109 +171,57 @@ static int ecw2cw(int ecw)
return (1 << ecw) - 1;
}
-/*
- * ieee80211_enable_ht should be called only after the operating band
- * has been determined as ht configuration depends on the hw's
- * HT abilities for a specific band.
- */
-static u32 ieee80211_enable_ht(struct ieee80211_sub_if_data *sdata,
- struct ieee80211_ht_operation *ht_oper,
- const u8 *bssid, u16 ap_ht_cap_flags,
- bool beacon_htcap_ie)
+static u32 ieee80211_config_ht_tx(struct ieee80211_sub_if_data *sdata,
+ struct ieee80211_ht_operation *ht_oper,
+ const u8 *bssid, bool reconfig)
{
struct ieee80211_local *local = sdata->local;
struct ieee80211_supported_band *sband;
struct sta_info *sta;
u32 changed = 0;
- int ht_cfreq;
u16 ht_opmode;
- bool enable_ht = true;
- enum nl80211_channel_type prev_chantype;
- enum nl80211_channel_type rx_channel_type = NL80211_CHAN_NO_HT;
- enum nl80211_channel_type tx_channel_type;
+ enum nl80211_channel_type channel_type;
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
- prev_chantype = sdata->vif.bss_conf.channel_type;
-
-
- ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,
- sband->band);
- /* check that channel matches the right operating channel */
- if (local->hw.conf.channel->center_freq != ht_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"
- " ht-cfreq: %d ht->control_chan: %d"
- " band: %d. Disabling HT.\n",
- sdata->name,
- local->hw.conf.channel->center_freq,
- ht_cfreq, ht_oper->primary_chan,
- sband->band);
- enable_ht = false;
- }
-
- if (enable_ht) {
- rx_channel_type = NL80211_CHAN_HT20;
-
- if (!(ap_ht_cap_flags & IEEE80211_HT_CAP_40MHZ_INTOLERANT) &&
- !ieee80111_cfg_override_disables_ht40(sdata) &&
- (sband->ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) &&
- (ht_oper->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY)) {
- switch(ht_oper->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) {
- case IEEE80211_HT_PARAM_CHA_SEC_ABOVE:
- rx_channel_type = NL80211_CHAN_HT40PLUS;
- break;
- case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
- rx_channel_type = NL80211_CHAN_HT40MINUS;
- break;
- }
- }
- }
+ channel_type = local->hw.conf.channel_type;
- tx_channel_type = ieee80211_get_tx_channel_type(local, rx_channel_type);
+ if (WARN_ON_ONCE(channel_type == NL80211_CHAN_NO_HT))
+ return 0;
- if (local->tmp_channel)
- local->tmp_channel_type = rx_channel_type;
+ channel_type = ieee80211_get_tx_channel_type(local, channel_type);
- if (!ieee80211_set_channel_type(local, sdata, rx_channel_type)) {
- /* can only fail due to HT40+/- mismatch */
- rx_channel_type = NL80211_CHAN_HT20;
- WARN_ON(!ieee80211_set_channel_type(local, sdata,
- rx_channel_type));
- }
+ /* This can change during the lifetime of the BSS */
+ if (!(ht_oper->ht_param & IEEE80211_HT_PARAM_CHAN_WIDTH_ANY))
+ channel_type = NL80211_CHAN_HT20;
- if (beacon_htcap_ie && (prev_chantype != rx_channel_type)) {
- /*
- * Whenever the AP announces the HT mode change that can be
- * 40MHz intolerant or etc., it would be safer to stop tx
- * queues before doing hw config to avoid buffer overflow.
- */
- ieee80211_stop_queues_by_reason(&sdata->local->hw,
+ if (!reconfig || (sdata->u.mgd.tx_chantype != channel_type)) {
+ if (reconfig) {
+ /*
+ * Whenever the AP announces the HT mode changed
+ * (e.g. 40 MHz intolerant) stop queues to avoid
+ * sending out frames while the rate control is
+ * reconfiguring.
+ */
+ ieee80211_stop_queues_by_reason(&sdata->local->hw,
IEEE80211_QUEUE_STOP_REASON_CHTYPE_CHANGE);
- /* flush out all packets */
- synchronize_net();
+ /* flush out all packets */
+ synchronize_net();
- drv_flush(local, false);
- }
-
- /* channel_type change automatically detected */
- ieee80211_hw_config(local, 0);
+ drv_flush(local, false);
+ }
- if (prev_chantype != tx_channel_type) {
rcu_read_lock();
sta = sta_info_get(sdata, bssid);
if (sta)
rate_control_rate_update(local, sband, sta,
IEEE80211_RC_HT_CHANGED,
- tx_channel_type);
+ channel_type);
rcu_read_unlock();
- if (beacon_htcap_ie)
+ sdata->u.mgd.tx_chantype = channel_type;
+
+ if (reconfig)
ieee80211_wake_queues_by_reason(&sdata->local->hw,
IEEE80211_QUEUE_STOP_REASON_CHTYPE_CHANGE);
}
@@ -281,12 +229,9 @@ static u32 ieee80211_enable_ht(struct ie
ht_opmode = le16_to_cpu(ht_oper->operation_mode);
/* if bss configuration changed store the new one */
- if (sdata->ht_opmode_valid != enable_ht ||
- sdata->vif.bss_conf.ht_operation_mode != ht_opmode ||
- prev_chantype != rx_channel_type) {
+ if (!reconfig || (sdata->vif.bss_conf.ht_operation_mode != ht_opmode)) {
changed |= BSS_CHANGED_HT;
sdata->vif.bss_conf.ht_operation_mode = ht_opmode;
- sdata->ht_opmode_valid = enable_ht;
}
return changed;
@@ -349,6 +294,16 @@ static void ieee80211_add_ht_ie(struct i
break;
}
+ /*
+ * If 40 MHz was disabled associate as though we weren't
+ * capable of 40 MHz -- some broken APs will never fall
+ * back to trying to transmit in 20 MHz.
+ */
+ if (sdata->u.mgd.flags & IEEE80211_STA_DISABLE_40MHZ) {
+ cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
+ cap &= ~IEEE80211_HT_CAP_SGI_40;
+ }
+
/* set SM PS mode properly */
cap &= ~IEEE80211_HT_CAP_SM_PS;
switch (smps) {
@@ -1426,7 +1381,6 @@ static void ieee80211_set_disassoc(struc
sdata->vif.bss_conf.assoc = false;
/* on the next assoc, re-program HT parameters */
- sdata->ht_opmode_valid = false;
memset(&ifmgd->ht_capa, 0, sizeof(ifmgd->ht_capa));
memset(&ifmgd->ht_capa_mask, 0, sizeof(ifmgd->ht_capa_mask));
@@ -1991,7 +1945,6 @@ static bool ieee80211_assoc_success(stru
struct ieee80211_bss_conf *bss_conf = &sdata->vif.bss_conf;
u32 changed = 0;
int err;
- u16 ap_ht_cap_flags;
/* AssocResp and ReassocResp have identical structure */
@@ -2042,8 +1995,6 @@ static bool ieee80211_assoc_success(stru
ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
elems.ht_cap_elem, &sta->sta.ht_cap);
- ap_ht_cap_flags = sta->sta.ht_cap.cap;
-
rate_control_rate_init(sta);
if (ifmgd->flags & IEEE80211_STA_MFP_ENABLED)
@@ -2085,9 +2036,8 @@ static bool ieee80211_assoc_success(stru
if (elems.ht_operation && elems.wmm_param &&
!(ifmgd->flags & IEEE80211_STA_DISABLE_11N))
- changed |= ieee80211_enable_ht(sdata, elems.ht_operation,
- cbss->bssid, ap_ht_cap_flags,
- false);
+ changed |= ieee80211_config_ht_tx(sdata, elems.ht_operation,
+ cbss->bssid, false);
/* set AID and assoc capability,
* ieee80211_set_associated() will tell the driver */
@@ -2497,29 +2447,12 @@ static void ieee80211_rx_mgmt_beacon(str
if (elems.ht_cap_elem && elems.ht_operation && elems.wmm_param &&
!(ifmgd->flags & IEEE80211_STA_DISABLE_11N)) {
- struct sta_info *sta;
struct ieee80211_supported_band *sband;
- u16 ap_ht_cap_flags;
-
- rcu_read_lock();
-
- sta = sta_info_get(sdata, bssid);
- if (WARN_ON(!sta)) {
- rcu_read_unlock();
- return;
- }
sband = local->hw.wiphy->bands[local->hw.conf.channel->band];
- ieee80211_ht_cap_ie_to_sta_ht_cap(sdata, sband,
- elems.ht_cap_elem, &sta->sta.ht_cap);
-
- ap_ht_cap_flags = sta->sta.ht_cap.cap;
-
- rcu_read_unlock();
-
- changed |= ieee80211_enable_ht(sdata, elems.ht_operation,
- bssid, ap_ht_cap_flags, true);
+ changed |= ieee80211_config_ht_tx(sdata, elems.ht_operation,
+ bssid, true);
}
/* Note: country IE parsing is done for us by cfg80211 */
@@ -3049,6 +2982,11 @@ static int ieee80211_prep_connection(str
struct sta_info *sta;
bool have_sta = false;
int err;
+ int ht_cfreq;
+ enum nl80211_channel_type channel_type = NL80211_CHAN_NO_HT;
+ const u8 *ht_oper_ie;
+ const struct ieee80211_ht_operation *ht_oper = NULL;
+ struct ieee80211_supported_band *sband;
if (WARN_ON(!ifmgd->auth_data && !ifmgd->assoc_data))
return -EINVAL;
@@ -3070,17 +3008,76 @@ static int ieee80211_prep_connection(str
mutex_unlock(&local->mtx);
/* switch to the right channel */
+ sband = local->hw.wiphy->bands[cbss->channel->band];
+
+ ifmgd->flags &= ~IEEE80211_STA_DISABLE_40MHZ;
+
+ if (sband->ht_cap.ht_supported) {
+ ht_oper_ie = cfg80211_find_ie(WLAN_EID_HT_OPERATION,
+ cbss->information_elements,
+ cbss->len_information_elements);
+ if (ht_oper_ie && ht_oper_ie[1] >= sizeof(*ht_oper))
+ ht_oper = (void *)(ht_oper_ie + 2);
+ }
+
+ if (ht_oper) {
+ ht_cfreq = ieee80211_channel_to_frequency(ht_oper->primary_chan,
+ cbss->channel->band);
+ /* check that channel matches the right operating channel */
+ if (cbss->channel->center_freq != ht_cfreq) {
+ /*
+ * It's possible that some APs are confused here;
+ * Netgear WNDR3700 sometimes reports 4 higher than
+ * the actual channel in association responses, but
+ * since we look at probe response/beacon data here
+ * it should be OK.
+ */
+ printk(KERN_DEBUG
+ "%s: Wrong control channel: center-freq: %d"
+ " ht-cfreq: %d ht->primary_chan: %d"
+ " band: %d. Disabling HT.\n",
+ sdata->name, cbss->channel->center_freq,
+ ht_cfreq, ht_oper->primary_chan,
+ cbss->channel->band);
+ ht_oper = NULL;
+ }
+ }
+
+ if (ht_oper) {
+ channel_type = NL80211_CHAN_HT20;
+
+ 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:
+ channel_type = NL80211_CHAN_HT40PLUS;
+ break;
+ case IEEE80211_HT_PARAM_CHA_SEC_BELOW:
+ channel_type = NL80211_CHAN_HT40MINUS;
+ break;
+ }
+ }
+ }
+
+ if (!ieee80211_set_channel_type(local, sdata, channel_type)) {
+ /* can only fail due to HT40+/- mismatch */
+ channel_type = NL80211_CHAN_HT20;
+ printk(KERN_DEBUG
+ "%s: disabling 40 MHz due to multi-vif mismatch\n",
+ sdata->name);
+ ifmgd->flags |= IEEE80211_STA_DISABLE_40MHZ;
+ WARN_ON(!ieee80211_set_channel_type(local, sdata,
+ channel_type));
+ }
+
local->oper_channel = cbss->channel;
- ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);
+ ieee80211_hw_config(local, 0);
if (!have_sta) {
- struct ieee80211_supported_band *sband;
u32 rates = 0, basic_rates = 0;
bool have_higher_than_11mbit;
int min_rate = INT_MAX, min_rate_index = -1;
- sband = sdata->local->hw.wiphy->bands[cbss->channel->band];
-
ieee80211_get_rates(sband, bss->supp_rates,
bss->supp_rates_len,
&rates, &basic_rates,
--- a/net/mac80211/ht.c 2012-03-15 15:32:26.000000000 +0100
+++ b/net/mac80211/ht.c 2012-03-15 15:50:36.000000000 +0100
@@ -19,15 +19,6 @@
#include "ieee80211_i.h"
#include "rate.h"
-bool ieee80111_cfg_override_disables_ht40(struct ieee80211_sub_if_data *sdata)
-{
- const __le16 flg = cpu_to_le16(IEEE80211_HT_CAP_SUP_WIDTH_20_40);
- if ((sdata->u.mgd.ht_capa_mask.cap_info & flg) &&
- !(sdata->u.mgd.ht_capa.cap_info & flg))
- return true;
- return false;
-}
-
static void __check_htcap_disable(struct ieee80211_sub_if_data *sdata,
struct ieee80211_sta_ht_cap *ht_cap,
u16 flag)
--- a/Documentation/networking/mac80211-auth-assoc-deauth.txt 2012-03-15 15:33:29.000000000 +0100
+++ b/Documentation/networking/mac80211-auth-assoc-deauth.txt 2012-03-15 16:29:02.000000000 +0100
@@ -23,7 +23,7 @@ BA session stop & deauth/disassoc frames
end note
end
-mac80211->driver: config(channel, non-HT)
+mac80211->driver: config(channel, channel type)
mac80211->driver: bss_info_changed(set BSSID, basic rate bitmap)
mac80211->driver: sta_state(AP, exists)
@@ -51,7 +51,7 @@ note over mac80211,driver: cleanup like
end
alt not previously authenticated (FT)
-mac80211->driver: config(channel, non-HT)
+mac80211->driver: config(channel, channel type)
mac80211->driver: bss_info_changed(set BSSID, basic rate bitmap)
mac80211->driver: sta_state(AP, exists)
mac80211->driver: sta_state(AP, authenticated)
@@ -67,10 +67,6 @@ end
mac80211->driver: set up QoS parameters
-alt is HT channel
-mac80211->driver: config(channel, HT params)
-end
-
mac80211->driver: bss_info_changed(QoS, HT, associated with AID)
mac80211->userspace: associated
@@ -95,5 +91,5 @@ mac80211->driver: sta_state(AP,exists)
mac80211->driver: sta_state(AP,not-exists)
mac80211->driver: turn off powersave
mac80211->driver: bss_info_changed(clear BSSID, not associated, no QoS, ...)
-mac80211->driver: config(non-HT channel type)
+mac80211->driver: config(channel type to non-HT)
mac80211->userspace: disconnected
--
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