cfg80211: module_param to disable HT40 in 2.4GHz band

[pandora-kernel.git] / net / wireless / core.c

diff --git a/net/wireless/core.c b/net/wireless/core.c
index fe01de2..bbf1fa1 100644 (file)
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -46,6 +46,11 @@ static struct dentry *ieee80211_debugfs_dir;
 /* for the cleanup, scan and event works */
 struct workqueue_struct *cfg80211_wq;
 
+static bool cfg80211_disable_40mhz_24ghz;
+module_param(cfg80211_disable_40mhz_24ghz, bool, 0644);
+MODULE_PARM_DESC(cfg80211_disable_40mhz_24ghz,
+                "Disable 40MHz support in the 2.4GHz band");
+
 /* requires cfg80211_mutex to be held! */
 struct cfg80211_registered_device *cfg80211_rdev_by_wiphy_idx(int wiphy_idx)
 {
@@ -450,6 +455,18 @@ int wiphy_register(struct wiphy *wiphy)
                if (WARN_ON(!sband->n_channels || !sband->n_bitrates))
                        return -EINVAL;
 
+               /*
+                * Since cfg80211_disable_40mhz_24ghz is global, we can
+                * modify the sband's ht data even if the driver uses a
+                * global structure for that.
+                */
+               if (cfg80211_disable_40mhz_24ghz &&
+                   band == IEEE80211_BAND_2GHZ &&
+                   sband->ht_cap.ht_supported) {
+                       sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40;
+                       sband->ht_cap.cap &= ~IEEE80211_HT_CAP_SGI_40;
+               }
+
                /*
                 * Since we use a u32 for rate bitmaps in
                 * ieee80211_get_response_rate, we cannot