blob: a46ac6c9b3655dbc056b8a20846a972b2bba9fdb [file] [log] [blame]
* This file contains helper code to handle channel
* settings and keeping track of what is possible at
* any point in time.
* Copyright 2009 Johannes Berg <>
#include <net/cfg80211.h>
#include "core.h"
struct ieee80211_channel *
rdev_fixed_channel(struct cfg80211_registered_device *rdev,
struct wireless_dev *for_wdev)
struct wireless_dev *wdev;
struct ieee80211_channel *result = NULL;
list_for_each_entry(wdev, &rdev->netdev_list, list) {
if (wdev == for_wdev)
* Lock manually to tell lockdep about allowed
* nesting here if for_wdev->mtx is held already.
* This is ok as it's all under the rdev devlist
* mutex and as such can only be done once at any
* given time.
mutex_lock_nested(&wdev->mtx, SINGLE_DEPTH_NESTING);
if (wdev->current_bss)
result = wdev->current_bss->;
if (result)
return result;
int rdev_set_freq(struct cfg80211_registered_device *rdev,
struct wireless_dev *for_wdev,
int freq, enum nl80211_channel_type channel_type)
struct ieee80211_channel *chan;
struct ieee80211_sta_ht_cap *ht_cap;
int result;
if (rdev_fixed_channel(rdev, for_wdev))
return -EBUSY;
if (!rdev->ops->set_channel)
chan = ieee80211_get_channel(&rdev->wiphy, freq);
/* Primary channel not allowed */
if (!chan || chan->flags & IEEE80211_CHAN_DISABLED)
return -EINVAL;
if (channel_type == NL80211_CHAN_HT40MINUS &&
chan->flags & IEEE80211_CHAN_NO_HT40MINUS)
return -EINVAL;
else if (channel_type == NL80211_CHAN_HT40PLUS &&
chan->flags & IEEE80211_CHAN_NO_HT40PLUS)
return -EINVAL;
ht_cap = &rdev->wiphy.bands[chan->band]->ht_cap;
if (channel_type != NL80211_CHAN_NO_HT) {
if (!ht_cap->ht_supported)
return -EINVAL;
if (!(ht_cap->cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40) ||
ht_cap->cap & IEEE80211_HT_CAP_40MHZ_INTOLERANT)
return -EINVAL;
result = rdev->ops->set_channel(&rdev->wiphy, chan, channel_type);
if (result)
return result;
rdev->channel = chan;
return 0;