From f38fd12fa7b7b98e158a9b31d388da34eef25c22 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 1 Dec 2009 18:29:42 +0100 Subject: [PATCH] mac80211: allow disabling 40MHz on 2.4GHz In some situations it is required that a system be configured with no support for 40 MHz channels in the 2.4 GHz band. Rather than imposing any such restrictions on everybody, allow configuration a system like that with a module parameter. It is writable at runtime but only takes effect at the time of the next association. Signed-off-by: Johannes Berg Signed-off-by: John W. Linville --- net/mac80211/ieee80211_i.h | 2 ++ net/mac80211/main.c | 6 ++++++ net/mac80211/mlme.c | 6 ++++++ net/mac80211/util.c | 14 +++++++++++--- 4 files changed, 25 insertions(+), 3 deletions(-) diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h index e63aecbddfb..6fb3f718153 100644 --- a/net/mac80211/ieee80211_i.h +++ b/net/mac80211/ieee80211_i.h @@ -881,6 +881,8 @@ void ieee80211_bss_info_change_notify(struct ieee80211_sub_if_data *sdata, void ieee80211_configure_filter(struct ieee80211_local *local); u32 ieee80211_reset_erp_info(struct ieee80211_sub_if_data *sdata); +extern bool ieee80211_disable_40mhz_24ghz; + /* STA code */ void ieee80211_sta_setup_sdata(struct ieee80211_sub_if_data *sdata); int ieee80211_mgd_auth(struct ieee80211_sub_if_data *sdata, diff --git a/net/mac80211/main.c b/net/mac80211/main.c index e1293e8ed83..25f52098b63 100644 --- a/net/mac80211/main.c +++ b/net/mac80211/main.c @@ -33,6 +33,12 @@ #include "cfg.h" #include "debugfs.h" + +bool ieee80211_disable_40mhz_24ghz; +module_param(ieee80211_disable_40mhz_24ghz, bool, 0644); +MODULE_PARM_DESC(ieee80211_disable_40mhz_24ghz, + "Disable 40MHz support in the 2.4GHz band"); + void ieee80211_configure_filter(struct ieee80211_local *local) { u64 mc; diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c index 0a762a9ba4d..a7472c979c6 100644 --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -400,6 +400,12 @@ static void ieee80211_send_assoc(struct ieee80211_sub_if_data *sdata, /* determine capability flags */ + if (ieee80211_disable_40mhz_24ghz && + sband->band == IEEE80211_BAND_2GHZ) { + cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; + cap &= ~IEEE80211_HT_CAP_SGI_40; + } + switch (ht_info->ht_param & IEEE80211_HT_PARAM_CHA_SEC_OFFSET) { case IEEE80211_HT_PARAM_CHA_SEC_ABOVE: if (flags & IEEE80211_CHAN_NO_HT40PLUS) { diff --git a/net/mac80211/util.c b/net/mac80211/util.c index 086ef6257b4..acb6626ad0a 100644 --- a/net/mac80211/util.c +++ b/net/mac80211/util.c @@ -908,16 +908,24 @@ int ieee80211_build_preq_ies(struct ieee80211_local *local, u8 *buffer, } if (sband->ht_cap.ht_supported) { - __le16 tmp = cpu_to_le16(sband->ht_cap.cap); + u16 cap = sband->ht_cap.cap; + __le16 tmp; + + if (ieee80211_disable_40mhz_24ghz && + sband->band == IEEE80211_BAND_2GHZ) { + cap &= ~IEEE80211_HT_CAP_SUP_WIDTH_20_40; + cap &= ~IEEE80211_HT_CAP_SGI_40; + } *pos++ = WLAN_EID_HT_CAPABILITY; *pos++ = sizeof(struct ieee80211_ht_cap); memset(pos, 0, sizeof(struct ieee80211_ht_cap)); + tmp = cpu_to_le16(cap); memcpy(pos, &tmp, sizeof(u16)); pos += sizeof(u16); - /* TODO: needs a define here for << 2 */ *pos++ = sband->ht_cap.ampdu_factor | - (sband->ht_cap.ampdu_density << 2); + (sband->ht_cap.ampdu_density << + IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT); memcpy(pos, &sband->ht_cap.mcs, sizeof(sband->ht_cap.mcs)); pos += sizeof(sband->ht_cap.mcs); pos += 2 + 4 + 1; /* ext info, BF cap, antsel */ -- 2.11.4.GIT