[MAC80211]: improved short preamble handling
Similarly to CTS protection, whether short preambles are used for 802.11b
transmissions should be a per-subif setting, not device global.
For STAs, this patch makes short preamble handling automatic based on the ERP
IE. For APs, hostapd still uses the prism ioctls, but the write ioctl has been
restricted to AP-only subifs.
ieee80211_txrx_data.short_preamble (an unused field) was removed.
Unfortunately, some API changes were required for the following functions:
- ieee80211_generic_frame_duration
- ieee80211_rts_duration
- ieee80211_ctstoself_duration
- ieee80211_rts_get
- ieee80211_ctstoself_get
Affected drivers were updated accordingly.
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/ieee80211_sta.c b/net/mac80211/ieee80211_sta.c
index 8e65489..0f5f813 100644
--- a/net/mac80211/ieee80211_sta.c
+++ b/net/mac80211/ieee80211_sta.c
@@ -318,6 +318,7 @@
struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
struct ieee80211_if_sta *ifsta = &sdata->u.sta;
int use_protection = (erp_value & WLAN_ERP_USE_PROTECTION) != 0;
+ int preamble_mode = (erp_value & WLAN_ERP_BARKER_PREAMBLE) != 0;
if (use_protection != sdata->use_protection) {
if (net_ratelimit()) {
@@ -329,6 +330,18 @@
}
sdata->use_protection = use_protection;
}
+
+ if (!preamble_mode != sdata->short_preamble) {
+ if (net_ratelimit()) {
+ printk(KERN_DEBUG "%s: switched to %s barker preamble"
+ " (BSSID=" MAC_FMT ")\n",
+ dev->name,
+ (preamble_mode == WLAN_ERP_PREAMBLE_SHORT) ?
+ "short" : "long",
+ MAC_ARG(ifsta->bssid));
+ }
+ sdata->short_preamble = !preamble_mode;
+ }
}
@@ -415,6 +428,7 @@
ieee80211_sta_send_associnfo(dev, ifsta);
} else {
netif_carrier_off(dev);
+ sdata->short_preamble = 0;
sdata->use_protection = 0;
memset(wrqu.ap_addr.sa_data, 0, ETH_ALEN);
}
@@ -2281,7 +2295,7 @@
"for IBSS beacon\n", dev->name);
break;
}
- control.tx_rate = (local->short_preamble &&
+ control.tx_rate = (sdata->short_preamble &&
(rate->flags & IEEE80211_RATE_PREAMBLE2)) ?
rate->val2 : rate->val;
control.antenna_sel_tx = local->hw.conf.antenna_sel_tx;
