--- a/net/mac80211/cfg.c
+++ b/net/mac80211/cfg.c
@@ -580,7 +580,8 @@ static int ieee80211_set_monitor_channel
 			ret = ieee80211_vif_use_channel(sdata, chandef,
 					IEEE80211_CHANCTX_EXCLUSIVE);
 		}
-	} else if (local_read(&local->open_count) == local->monitors) {
+       // Patch: Always allow channel change, even if a normal virtual interface is present
+       } else /*if (local_read(&local->open_count) == local->monitors)*/ {
 		local->_oper_chandef = *chandef;
 		ieee80211_hw_config(local, 0);
 	}
--- a/net/mac80211/tx.c
+++ b/net/mac80211/tx.c
@@ -795,11 +795,19 @@ ieee80211_tx_h_sequence(struct ieee80211
 
 	/*
 	 * Packet injection may want to control the sequence
-	 * number, if we have no matching interface then we
-	 * neither assign one ourselves nor ask the driver to.
+	 * number, so if an injected packet is found, skip
+	 * renumbering it. Also make the packet NO_ACK to avoid
+	 * excessive retries (ACKing and retrying should be
+	 * handled by the injecting application).
+	 * FIXME This may break hostapd and some other injectors.
+	 * This should be done using a radiotap flag.
 	 */
-	if (unlikely(info->control.vif->type == NL80211_IFTYPE_MONITOR))
+	if (unlikely((info->flags & IEEE80211_TX_CTL_INJECTED) &&
+	   !(tx->sdata->u.mntr.flags & MONITOR_FLAG_COOK_FRAMES))) {
+		if (!ieee80211_has_morefrags(hdr->frame_control))
+			info->flags |= IEEE80211_TX_CTL_NO_ACK;
 		return TX_CONTINUE;
+	}
 
 	if (unlikely(ieee80211_is_ctl(hdr->frame_control)))
 		return TX_CONTINUE;
@@ -1659,7 +1667,10 @@ void ieee80211_xmit(struct ieee80211_sub
 		}
 	}
 
-	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, sta, skb, false);
 }
 
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -857,8 +857,10 @@ 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);
 }
--- a/drivers/net/wireless/zydas/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zydas/zd1211rw/zd_mac.c
@@ -242,14 +242,19 @@ void zd_mac_clear(struct zd_mac *mac)
 static int set_rx_filter(struct zd_mac *mac)
 {
 	unsigned long flags;
-	u32 filter = STA_RX_FILTER;
+	struct zd_ioreq32 ioreqs[] = {
+		{CR_RX_FILTER, STA_RX_FILTER},
+		{ CR_SNIFFER_ON, 0U },
+	};
 
 	spin_lock_irqsave(&mac->lock, flags);
-	if (mac->pass_ctrl)
-		filter |= RX_FILTER_CTRL;
+	if (mac->pass_ctrl) {
+		ioreqs[0].value |= 0xFFFFFFFF;
+		ioreqs[1].value = 0x1;
+	}
 	spin_unlock_irqrestore(&mac->lock, flags);
 
-	return zd_iowrite32(&mac->chip, CR_RX_FILTER, filter);
+	return zd_iowrite32a(&mac->chip, ioreqs, ARRAY_SIZE(ioreqs));
 }
 
 static int set_mac_and_bssid(struct zd_mac *mac)
@@ -1057,7 +1062,8 @@ int zd_mac_rx(struct ieee80211_hw *hw, c
 	/* Caller has to ensure that length >= sizeof(struct rx_status). */
 	status = (struct rx_status *)
 		(buffer + (length - sizeof(struct rx_status)));
-	if (status->frame_status & ZD_RX_ERROR) {
+	if ((status->frame_status & ZD_RX_ERROR) || 
+		(status->frame_status & ~0x21)) {
 		if (mac->pass_failed_fcs &&
 				(status->frame_status & ZD_RX_CRC32_ERROR)) {
 			stats.flag |= RX_FLAG_FAILED_FCS_CRC;
@@ -1400,7 +1406,7 @@ struct ieee80211_hw *zd_mac_alloc_hw(str
 	ieee80211_hw_set(hw, MFP_CAPABLE);
 	ieee80211_hw_set(hw, HOST_BROADCAST_PS_BUFFERING);
 	ieee80211_hw_set(hw, RX_INCLUDES_FCS);
-	ieee80211_hw_set(hw, SIGNAL_UNSPEC);
+	ieee80211_hw_set(hw, SIGNAL_DBM);
 
 	hw->wiphy->interface_modes =
 		BIT(NL80211_IFTYPE_MESH_POINT) |
--- a/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
+++ b/drivers/net/wireless/realtek/rtl818x/rtl8187/dev.c
@@ -251,8 +251,17 @@ 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;
+		}
+	}
 
 	/* HW will perform RTS-CTS when only RTS flags is set.
 	 * HW will perform CTS-to-self when both RTS and CTS flags are set.
