mac80211: fix short slot handling
This patch makes mac80211 handle short slot requests from the AP
properly. Also warn about uses of IEEE80211_CONF_SHORT_SLOT_TIME
and optimise out the code since it cannot ever be hit anyway.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
index 6ad2619..829995e 100644
--- a/net/mac80211/mlme.c
+++ b/net/mac80211/mlme.c
@@ -568,15 +568,27 @@
}
}
-static u32 ieee80211_handle_protect_preamb(struct ieee80211_sub_if_data *sdata,
- bool use_protection,
- bool use_short_preamble)
+static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
+ u16 capab, bool erp_valid, u8 erp)
{
struct ieee80211_bss_conf *bss_conf = &sdata->bss_conf;
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
struct ieee80211_if_sta *ifsta = &sdata->u.sta;
#endif
u32 changed = 0;
+ bool use_protection;
+ bool use_short_preamble;
+ bool use_short_slot;
+
+ if (erp_valid) {
+ use_protection = (erp & WLAN_ERP_USE_PROTECTION) != 0;
+ use_short_preamble = (erp & WLAN_ERP_BARKER_PREAMBLE) == 0;
+ } else {
+ use_protection = false;
+ use_short_preamble = !!(capab & WLAN_CAPABILITY_SHORT_PREAMBLE);
+ }
+
+ use_short_slot = !!(capab & WLAN_CAPABILITY_SHORT_SLOT_TIME);
if (use_protection != bss_conf->use_cts_prot) {
#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
@@ -605,30 +617,18 @@
changed |= BSS_CHANGED_ERP_PREAMBLE;
}
- return changed;
-}
-
-static u32 ieee80211_handle_erp_ie(struct ieee80211_sub_if_data *sdata,
- u8 erp_value)
-{
- bool use_protection = (erp_value & WLAN_ERP_USE_PROTECTION) != 0;
- bool use_short_preamble = (erp_value & WLAN_ERP_BARKER_PREAMBLE) == 0;
-
- return ieee80211_handle_protect_preamb(sdata,
- use_protection, use_short_preamble);
-}
-
-static u32 ieee80211_handle_bss_capability(struct ieee80211_sub_if_data *sdata,
- struct ieee80211_bss *bss)
-{
- u32 changed = 0;
-
- if (bss->has_erp_value)
- changed |= ieee80211_handle_erp_ie(sdata, bss->erp_value);
- else {
- u16 capab = bss->capability;
- changed |= ieee80211_handle_protect_preamb(sdata, false,
- (capab & WLAN_CAPABILITY_SHORT_PREAMBLE) != 0);
+ if (use_short_slot != bss_conf->use_short_slot) {
+#ifdef CONFIG_MAC80211_VERBOSE_DEBUG
+ if (net_ratelimit()) {
+ printk(KERN_DEBUG "%s: switched to %s slot"
+ " (BSSID=%s)\n",
+ sdata->dev->name,
+ use_short_slot ? "short" : "long",
+ ifsta->bssid);
+ }
+#endif
+ bss_conf->use_short_slot = use_short_slot;
+ changed |= BSS_CHANGED_ERP_SLOT;
}
return changed;
@@ -721,7 +721,8 @@
sdata->bss_conf.timestamp = bss->timestamp;
sdata->bss_conf.dtim_period = bss->dtim_period;
- changed |= ieee80211_handle_bss_capability(sdata, bss);
+ changed |= ieee80211_handle_bss_capability(sdata,
+ bss->capability, bss->has_erp_value, bss->erp_value);
ieee80211_rx_bss_put(local, bss);
}
@@ -1657,6 +1658,8 @@
struct ieee80211_local *local = sdata->local;
struct ieee80211_conf *conf = &local->hw.conf;
u32 changed = 0;
+ bool erp_valid;
+ u8 erp_value = 0;
/* Process beacon from the current BSS */
baselen = (u8 *) mgmt->u.beacon.variable - (u8 *) mgmt;
@@ -1678,13 +1681,16 @@
ieee80211_sta_wmm_params(local, ifsta, elems.wmm_param,
elems.wmm_param_len);
- if (elems.erp_info && elems.erp_info_len >= 1)
- changed |= ieee80211_handle_erp_ie(sdata, elems.erp_info[0]);
- else {
- u16 capab = le16_to_cpu(mgmt->u.beacon.capab_info);
- changed |= ieee80211_handle_protect_preamb(sdata, false,
- (capab & WLAN_CAPABILITY_SHORT_PREAMBLE) != 0);
+
+ if (elems.erp_info && elems.erp_info_len >= 1) {
+ erp_valid = true;
+ erp_value = elems.erp_info[0];
+ } else {
+ erp_valid = false;
}
+ changed |= ieee80211_handle_bss_capability(sdata,
+ le16_to_cpu(mgmt->u.beacon.capab_info),
+ erp_valid, erp_value);
if (elems.ht_cap_elem && elems.ht_info_elem &&
elems.wmm_param && conf->flags & IEEE80211_CONF_SUPPORT_HT_MODE) {