cfg80211: module_param to disable HT40 in 2.4GHz band
Currently mac80211 uses ieee80211_disable_40mhz_24ghz module
parameter to allow disabling 40MHz operation in the 2.4GHz band.
Move this handling from mac80211 to cfg80211 so that the feature
will be more generic.
Signed-off-by: Amitkumar Karwar <akarwar@marvell.com>
Signed-off-by: Bing Zhao <bzhao@marvell.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/wireless/core.c b/net/wireless/core.c
index fe01de2..bbf1fa1 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -46,6 +46,11 @@
/* 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)
{
@@ -451,6 +456,18 @@
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
* have more than 32 legacy rates.