compatdrivers_chan_qos_frag

 *original patch by Mathy Vanhoef
 *http://www.mathyvanhoef.com/2012/09/compat-wireless-injection-patch-for.html
 *fixed in offset by Devil_D
 *fixed new driver backports-3.12-1 @feelingfree
diff -r 6b71629b673d drivers/net/wireless/rtl818x/rtl8187/dev.c
--- a/drivers/net/wireless/rtl818x/rtl8187/dev.c	Tue May 28 16:57:23 2013 -0400
+++ b/drivers/net/wireless/rtl818x/rtl8187/dev.c	Tue May 28 17:16:15 2013 -0400
@@ -252,8 +252,18 @@ static void rtl8187_tx(struct ieee80211_
 	flags |= RTL818X_TX_DESC_FLAG_NO_ENC;

 	flags |= ieee80211_get_tx_rate(dev, info)->hw_value << 24;
+
+	// When this flag is set the firmware waits untill ALL fragments have
+	// reached the USB device. Then it sends the first fragment and waits
+	// for ACKS's. Of course in monitor mode it won't detect these ACK's.
 	if (ieee80211_has_morefrags(tx_hdr->frame_control))
-		flags |= RTL818X_TX_DESC_FLAG_MOREFRAG;
+	{
+		// If info->control.vif is NULL it's most likely in monitor mode
+		if (likely(info->control.vif != NULL && info->control.vif->type != NL80211_IFTYPE_MONITOR)) {
+			flags |= RTL818X_TX_DESC_FLAG_MOREFRAG;
+		}
+	}
+
 	if (info->control.rates[0].flags & IEEE80211_TX_RC_USE_RTS_CTS) {
 		flags |= RTL818X_TX_DESC_FLAG_RTS;
 		flags |= ieee80211_get_rts_cts_rate(dev, info)->hw_value << 19;
diff -r 6b71629b673d net/mac80211/cfg.c
--- a/net/mac80211/cfg.c	2014-06-09 08:55:25.073219859 +0700
+++ b/net/mac80211/cfg.c	2014-06-09 08:53:15.929594845 +0700
@@ -826,7 +826,8 @@
 			ret = ieee80211_vif_use_channel(sdata, chandef,
 					IEEE80211_CHANCTX_EXCLUSIVE);
 		}
-	} else if (local->open_count == local->monitors) {
+	// Patch: Always allow channel change, even if a normal virtual interface is present
+	} else /*if (local->open_count == local->monitors)*/ {
 		local->_oper_chandef = *chandef;
 		ieee80211_hw_config(local, 0);
 	}
diff -r 6b71629b673d net/mac80211/tx.c
--- a/net/mac80211/tx.c	Tue May 28 16:57:23 2013 -0400
+++ b/net/mac80211/tx.c	Tue May 28 17:16:15 2013 -0400
@@ -1482,7 +1582,10 @@ void ieee80211_xmit(struct ieee80211_sub
 	/* Older kernels do not have the select_queue callback */
 	skb_set_queue_mapping(skb, ieee80211_select_queue(sdata, skb));
 #endif
-	ieee80211_set_qos_hdr(sdata, skb);
+	// Don't overwrite QoS header in monitor mode
+	if (likely(info->control.vif->type != NL80211_IFTYPE_MONITOR)) {
+		ieee80211_set_qos_hdr(sdata, skb);
+	}
 	ieee80211_tx(sdata, skb, false, band);
 }

diff -r 6b71629b673d net/wireless/chan.c
--- a/net/wireless/chan.c	Tue May 28 16:57:23 2013 -0400
+++ b/net/wireless/chan.c	Tue May 28 17:16:15 2013 -0400
@@ -480,8 +480,10 @@ int cfg80211_set_monitor_channel(struct
 {
 	if (!rdev->ops->set_monitor_channel)
 		return -EOPNOTSUPP;
-	if (!cfg80211_has_monitors_only(rdev))
-		return -EBUSY;
+	// Always allow user to change channel, even if there is another normal
+	// virtual interface using the device.
+	//if (!cfg80211_has_monitors_only(rdev))
+	//	return -EBUSY;

 	return rdev_set_monitor_channel(rdev, chandef);
 }