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mac80211: improve HT channel handling

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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: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Johannes Berg
2010-05-05 15:28:27 +02:00
committed by John W. Linville
parent f444de05d2
commit 0aaffa9b96
8 changed files with 132 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files

70
net/mac80211/chan.c
View File

@ -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;
}