Commit 0aaffa9b authored by Johannes Berg's avatar Johannes Berg Committed by John W. Linville
Browse files

mac80211: improve HT channel handling 



Currently, when one interface switches HT mode,
all others will follow along. This is clearly
undesirable, since the new one might switch to
no-HT while another one is operating in HT.

Address this issue by keeping track of the HT
mode per interface, and allowing only changes
that are compatible, i.e. switching into HT40+
is not possible when another interface is in
HT40-, in that case the second one needs to
fall back to HT20.

Also, to allow drivers to know what's going on,
store the per-interface HT mode (channel type)
in the virtual interface's bss_conf.

Signed-off-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Signed-off-by: default avatarJohn W. Linville <linville@tuxdriver.com>
parent f444de05

drivers/net/wireless/mac80211_hwsim.c

+10 −9
Original line number Diff line number Diff line
@@ -651,17 +651,17 @@ static void mac80211_hwsim_beacon(unsigned long arg) 
	add_timer(&data->beacon_timer);

}





static int mac80211_hwsim_config(struct ieee80211_hw *hw, u32 changed)

{

	struct mac80211_hwsim_data *data = hw->priv;

	struct ieee80211_conf *conf = &hw->conf;

	static const char *chantypes[4] = {

static const char *hwsim_chantypes[] = {

	[NL80211_CHAN_NO_HT] = "noht",

	[NL80211_CHAN_HT20] = "ht20",

	[NL80211_CHAN_HT40MINUS] = "ht40-",

	[NL80211_CHAN_HT40PLUS] = "ht40+",

};



static int mac80211_hwsim_config(struct ieee80211_hw *hw, u32 changed)

{

	struct mac80211_hwsim_data *data = hw->priv;

	struct ieee80211_conf *conf = &hw->conf;

	static const char *smps_modes[IEEE80211_SMPS_NUM_MODES] = {

		[IEEE80211_SMPS_AUTOMATIC] = "auto",

		[IEEE80211_SMPS_OFF] = "off",
@@ -672,7 +672,7 @@ static int mac80211_hwsim_config(struct ieee80211_hw *hw, u32 changed) 
	printk(KERN_DEBUG "%s:%s (freq=%d/%s idle=%d ps=%d smps=%s)\n",

	       wiphy_name(hw->wiphy), __func__,

	       conf->channel->center_freq,

	       chantypes[conf->channel_type],

	       hwsim_chantypes[conf->channel_type],

	       !!(conf->flags & IEEE80211_CONF_IDLE),

	       !!(conf->flags & IEEE80211_CONF_PS),

	       smps_modes[conf->smps_mode]);
@@ -760,9 +760,10 @@ static void mac80211_hwsim_bss_info_changed(struct ieee80211_hw *hw, 
	}



	if (changed & BSS_CHANGED_HT) {

		printk(KERN_DEBUG "  %s: HT: op_mode=0x%x\n",

		printk(KERN_DEBUG "  %s: HT: op_mode=0x%x, chantype=%s\n",

		       wiphy_name(hw->wiphy),

		       info->ht_operation_mode);

		       info->ht_operation_mode,

		       hwsim_chantypes[info->channel_type]);

	}



	if (changed & BSS_CHANGED_BASIC_RATES) {

include/net/mac80211.h

+4 −0
Original line number Diff line number Diff line
@@ -191,6 +191,9 @@ enum ieee80211_bss_change { 
 *	the current band.

 * @bssid: The BSSID for this BSS

 * @enable_beacon: whether beaconing should be enabled or not

 * @channel_type: Channel type for this BSS -- the hardware might be

 *	configured for HT40+ while this BSS only uses no-HT, for

 *	example.

 * @ht_operation_mode: HT operation mode (like in &struct ieee80211_ht_info).

 *	This field is only valid when the channel type is one of the HT types.

 * @cqm_rssi_thold: Connection quality monitor RSSI threshold, a zero value
@@ -215,6 +218,7 @@ struct ieee80211_bss_conf { 
	u16 ht_operation_mode;

	s32 cqm_rssi_thold;

	u32 cqm_rssi_hyst;

	enum nl80211_channel_type channel_type;

};



/**

net/mac80211/cfg.c

+17 −6
Original line number Diff line number Diff line
@@ -1166,23 +1166,34 @@ static int ieee80211_set_channel(struct wiphy *wiphy, 
				 enum nl80211_channel_type channel_type)

{

	struct ieee80211_local *local = wiphy_priv(wiphy);

	struct ieee80211_sub_if_data *sdata = NULL;



	if (netdev)

		sdata = IEEE80211_DEV_TO_SUB_IF(netdev);



	switch (ieee80211_get_channel_mode(local, NULL)) {

	case CHAN_MODE_HOPPING:

		return -EBUSY;

	case CHAN_MODE_FIXED:

		if (local->oper_channel == chan &&

		    local->oper_channel_type == channel_type)

			return 0;

		if (local->oper_channel != chan)

			return -EBUSY;

		if (!sdata && local->_oper_channel_type == channel_type)

			return 0;

		break;

	case CHAN_MODE_UNDEFINED:

		break;

	}



	local->oper_channel = chan;

	local->oper_channel_type = channel_type;



	return ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

	if (!ieee80211_set_channel_type(local, sdata, channel_type))

		return -EBUSY;



	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);

	if (sdata && sdata->vif.type != NL80211_IFTYPE_MONITOR)

		ieee80211_bss_info_change_notify(sdata, BSS_CHANGED_HT);



	return 0;

}



#ifdef CONFIG_PM
@@ -1406,7 +1417,7 @@ int __ieee80211_request_smps(struct ieee80211_sub_if_data *sdata, 
	 * association, there's no need to send an action frame.

	 */

	if (!sdata->u.mgd.associated ||

	    sdata->local->oper_channel_type == NL80211_CHAN_NO_HT) {

	    sdata->vif.bss_conf.channel_type == NL80211_CHAN_NO_HT) {

		mutex_lock(&sdata->local->iflist_mtx);

		ieee80211_recalc_smps(sdata->local, sdata);

		mutex_unlock(&sdata->local->iflist_mtx);

net/mac80211/chan.c

+70 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
 * mac80211 - channel management

 */



#include <linux/nl80211.h>

#include "ieee80211_i.h"



enum ieee80211_chan_mode
@@ -55,3 +56,72 @@ ieee80211_get_channel_mode(struct ieee80211_local *local, 


	return mode;

}



bool ieee80211_set_channel_type(struct ieee80211_local *local,

				struct ieee80211_sub_if_data *sdata,

				enum nl80211_channel_type chantype)

{

	struct ieee80211_sub_if_data *tmp;

	enum nl80211_channel_type superchan = NL80211_CHAN_NO_HT;

	bool result;



	mutex_lock(&local->iflist_mtx);



	list_for_each_entry(tmp, &local->interfaces, list) {

		if (tmp == sdata)

			continue;



		if (!ieee80211_sdata_running(tmp))

			continue;



		switch (tmp->vif.bss_conf.channel_type) {

		case NL80211_CHAN_NO_HT:

		case NL80211_CHAN_HT20:

			superchan = tmp->vif.bss_conf.channel_type;

			break;

		case NL80211_CHAN_HT40PLUS:

			WARN_ON(superchan == NL80211_CHAN_HT40MINUS);

			superchan = NL80211_CHAN_HT40PLUS;

			break;

		case NL80211_CHAN_HT40MINUS:

			WARN_ON(superchan == NL80211_CHAN_HT40PLUS);

			superchan = NL80211_CHAN_HT40MINUS;

			break;

		}

	}



	switch (superchan) {

	case NL80211_CHAN_NO_HT:

	case NL80211_CHAN_HT20:

		/*

		 * allow any change that doesn't go to no-HT

		 * (if it already is no-HT no change is needed)

		 */

		if (chantype == NL80211_CHAN_NO_HT)

			break;

		superchan = chantype;

		break;

	case NL80211_CHAN_HT40PLUS:

	case NL80211_CHAN_HT40MINUS:

		/* allow smaller bandwidth and same */

		if (chantype == NL80211_CHAN_NO_HT)

			break;

		if (chantype == NL80211_CHAN_HT20)

			break;

		if (superchan == chantype)

			break;

		result = false;

		goto out;

	}



	local->_oper_channel_type = superchan;



	if (sdata)

		sdata->vif.bss_conf.channel_type = chantype;



	result = true;

 out:

	mutex_unlock(&local->iflist_mtx);



	return result;

}

net/mac80211/ibss.c

+3 −2
Original line number Diff line number Diff line
@@ -102,7 +102,7 @@ static void __ieee80211_sta_join_ibss(struct ieee80211_sub_if_data *sdata, 
	sdata->drop_unencrypted = capability & WLAN_CAPABILITY_PRIVACY ? 1 : 0;



	local->oper_channel = chan;

	local->oper_channel_type = NL80211_CHAN_NO_HT;

	WARN_ON(!ieee80211_set_channel_type(local, sdata, NL80211_CHAN_NO_HT));

	ieee80211_hw_config(local, IEEE80211_CONF_CHANGE_CHANNEL);



	sband = local->hw.wiphy->bands[chan->band];
@@ -910,7 +910,8 @@ int ieee80211_ibss_join(struct ieee80211_sub_if_data *sdata, 
	/* fix ourselves to that channel now already */

	if (params->channel_fixed) {

		sdata->local->oper_channel = params->channel;

		sdata->local->oper_channel_type = NL80211_CHAN_NO_HT;

		WARN_ON(!ieee80211_set_channel_type(sdata->local, sdata,

						    NL80211_CHAN_NO_HT));

	}



	if (params->ie) {

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