Merging upstream version 6.7.7.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 79 insertions, 55 deletions

diff --git a/include/net/mac80211.h b/include/net/mac80211.h
index 7c707358d..580781ff9 100644
--- a/include/net/mac80211.h
+++ b/include/net/mac80211.h
@@ -79,7 +79,7 @@
  * helpers for sanity checking. Drivers must ensure all work added onto the
  * mac80211 workqueue should be cancelled on the driver stop() callback.
  *
- * mac80211 will flushed the workqueue upon interface removal and during
+ * mac80211 will flush the workqueue upon interface removal and during
  * suspend.
  *
  * All work performed on the mac80211 workqueue must not acquire the RTNL lock.
@@ -138,7 +138,7 @@
  * field to the frame RX timestamp and report the ack TX timestamp in the
  * ieee80211_rx_status struct.
  *
- * Similarly, To report hardware timestamps for Timing Measurement or Fine
+ * Similarly, to report hardware timestamps for Timing Measurement or Fine
  * Timing Measurement frame TX, the driver should set the SKB's hwtstamp field
  * to the frame TX timestamp and report the ack RX timestamp in the
  * ieee80211_tx_status struct.
@@ -341,6 +341,7 @@ struct ieee80211_vif_chanctx_switch {
  * @BSS_CHANGED_UNSOL_BCAST_PROBE_RESP: Unsolicited broadcast probe response
  *	status changed.
  * @BSS_CHANGED_EHT_PUNCTURING: The channel puncturing bitmap changed.
+ * @BSS_CHANGED_MLD_VALID_LINKS: MLD valid links status changed.
  */
 enum ieee80211_bss_change {
 	BSS_CHANGED_ASSOC		= 1<<0,
@@ -376,6 +377,7 @@ enum ieee80211_bss_change {
 	BSS_CHANGED_FILS_DISCOVERY      = 1<<30,
 	BSS_CHANGED_UNSOL_BCAST_PROBE_RESP = 1<<31,
 	BSS_CHANGED_EHT_PUNCTURING	= BIT_ULL(32),
+	BSS_CHANGED_MLD_VALID_LINKS	= BIT_ULL(33),
 
 	/* when adding here, make sure to change ieee80211_reconfig */
 };
@@ -643,9 +645,7 @@ struct ieee80211_fils_discovery {
  * @pwr_reduction: power constraint of BSS.
  * @eht_support: does this BSS support EHT
  * @eht_puncturing: bitmap to indicate which channels are punctured in this BSS
- * @csa_active: marks whether a channel switch is going on. Internally it is
- *	write-protected by sdata_lock and local->mtx so holding either is fine
- *	for read access.
+ * @csa_active: marks whether a channel switch is going on.
  * @csa_punct_bitmap: new puncturing bitmap for channel switch
  * @mu_mimo_owner: indicates interface owns MU-MIMO capability
  * @chanctx_conf: The channel context this interface is assigned to, or %NULL
@@ -653,9 +653,7 @@ struct ieee80211_fils_discovery {
  *	path needing to access it; even though the netdev carrier will always
  *	be off when it is %NULL there can still be races and packets could be
  *	processed after it switches back to %NULL.
- * @color_change_active: marks whether a color change is ongoing. Internally it is
- *	write-protected by sdata_lock and local->mtx so holding either is fine
- *	for read access.
+ * @color_change_active: marks whether a color change is ongoing.
  * @color_change_color: the bss color that will be used after the change.
  * @ht_ldpc: in AP mode, indicates interface has HT LDPC capability.
  * @vht_ldpc: in AP mode, indicates interface has VHT LDPC capability.
@@ -1082,6 +1080,11 @@ struct ieee80211_tx_rate {
 
 #define IEEE80211_MAX_TX_RETRY		31
 
+static inline bool ieee80211_rate_valid(struct ieee80211_tx_rate *rate)
+{
+	return rate->idx >= 0 && rate->count > 0;
+}
+
 static inline void ieee80211_rate_set_vht(struct ieee80211_tx_rate *rate,
 					  u8 mcs, u8 nss)
 {
@@ -1115,7 +1118,9 @@ ieee80211_rate_get_vht_nss(const struct ieee80211_tx_rate *rate)
  *	not valid if the interface is an MLD since we won't know which
  *	link the frame will be transmitted on
  * @hw_queue: HW queue to put the frame on, skb_get_queue_mapping() gives the AC
- * @ack_frame_id: internal frame ID for TX status, used internally
+ * @status_data: internal data for TX status handling, assigned privately,
+ *	see also &enum ieee80211_status_data for the internal documentation
+ * @status_data_idr: indicates status data is IDR allocated ID for ack frame
  * @tx_time_est: TX time estimate in units of 4us, used internally
  * @control: union part for control data
  * @control.rates: TX rates array to try
@@ -1155,10 +1160,11 @@ struct ieee80211_tx_info {
 	/* common information */
 	u32 flags;
 	u32 band:3,
-	    ack_frame_id:13,
+	    status_data_idr:1,
+	    status_data:13,
 	    hw_queue:4,
 	    tx_time_est:10;
-	/* 2 free bits */
+	/* 1 free bit */
 
 	union {
 		struct {
@@ -1172,7 +1178,11 @@ struct ieee80211_tx_info {
 					u8 use_cts_prot:1;
 					u8 short_preamble:1;
 					u8 skip_table:1;
-					/* 2 bytes free */
+
+					/* for injection only (bitmap) */
+					u8 antennas:2;
+
+					/* 14 bits free */
 				};
 				/* only needed before rate control */
 				unsigned long jiffies;
@@ -1757,15 +1767,15 @@ struct ieee80211_channel_switch {
  * @IEEE80211_VIF_GET_NOA_UPDATE: request to handle NOA attributes
  *	and send P2P_PS notification to the driver if NOA changed, even
  *	this is not pure P2P vif.
- * @IEEE80211_VIF_DISABLE_SMPS_OVERRIDE: disable user configuration of
- *	SMPS mode via debugfs.
+ * @IEEE80211_VIF_EML_ACTIVE: The driver indicates that EML operation is
+ *      enabled for the interface.
  */
 enum ieee80211_vif_flags {
 	IEEE80211_VIF_BEACON_FILTER		= BIT(0),
 	IEEE80211_VIF_SUPPORTS_CQM_RSSI		= BIT(1),
 	IEEE80211_VIF_SUPPORTS_UAPSD		= BIT(2),
 	IEEE80211_VIF_GET_NOA_UPDATE		= BIT(3),
-	IEEE80211_VIF_DISABLE_SMPS_OVERRIDE	= BIT(4),
+	IEEE80211_VIF_EML_ACTIVE	        = BIT(4),
 };
 
 
@@ -1938,7 +1948,7 @@ static inline bool ieee80211_vif_is_mld(const struct ieee80211_vif *vif)
 	for (link_id = 0; link_id < ARRAY_SIZE((vif)->link_conf); link_id++)	\
 		if ((!(vif)->active_links ||					\
 		     (vif)->active_links & BIT(link_id)) &&			\
-		    (link = rcu_dereference((vif)->link_conf[link_id])))
+		    (link = link_conf_dereference_check(vif, link_id)))
 
 static inline bool ieee80211_vif_is_mesh(struct ieee80211_vif *vif)
 {
@@ -1971,22 +1981,18 @@ struct ieee80211_vif *wdev_to_ieee80211_vif(struct wireless_dev *wdev);
  */
 struct wireless_dev *ieee80211_vif_to_wdev(struct ieee80211_vif *vif);
 
-/**
- * lockdep_vif_mutex_held - for lockdep checks on link poiners
- * @vif: the interface to check
- */
-static inline bool lockdep_vif_mutex_held(struct ieee80211_vif *vif)
+static inline bool lockdep_vif_wiphy_mutex_held(struct ieee80211_vif *vif)
 {
-	return lockdep_is_held(&ieee80211_vif_to_wdev(vif)->mtx);
+	return lockdep_is_held(&ieee80211_vif_to_wdev(vif)->wiphy->mtx);
 }
 
 #define link_conf_dereference_protected(vif, link_id)		\
 	rcu_dereference_protected((vif)->link_conf[link_id],	\
-				  lockdep_vif_mutex_held(vif))
+				  lockdep_vif_wiphy_mutex_held(vif))
 
 #define link_conf_dereference_check(vif, link_id)		\
 	rcu_dereference_check((vif)->link_conf[link_id],	\
-			      lockdep_vif_mutex_held(vif))
+			      lockdep_vif_wiphy_mutex_held(vif))
 
 /**
  * enum ieee80211_key_flags - key flags
@@ -2393,7 +2399,7 @@ static inline bool lockdep_sta_mutex_held(struct ieee80211_sta *pubsta)
 	for (link_id = 0; link_id < ARRAY_SIZE((sta)->link); link_id++)		\
 		if ((!(vif)->active_links ||					\
 		     (vif)->active_links & BIT(link_id)) &&			\
-		    ((link_sta) = link_sta_dereference_protected(sta, link_id)))
+		    ((link_sta) = link_sta_dereference_check(sta, link_id)))
 
 /**
  * enum sta_notify_cmd - sta notify command
@@ -3056,7 +3062,7 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * The set_key() call for the %SET_KEY command should return 0 if
  * the key is now in use, -%EOPNOTSUPP or -%ENOSPC if it couldn't be
  * added; if you return 0 then hw_key_idx must be assigned to the
- * hardware key index, you are free to use the full u8 range.
+ * hardware key index. You are free to use the full u8 range.
  *
  * Note that in the case that the @IEEE80211_HW_SW_CRYPTO_CONTROL flag is
  * set, mac80211 will not automatically fall back to software crypto if
@@ -3066,7 +3072,7 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * When the cmd is %DISABLE_KEY then it must succeed.
  *
  * Note that it is permissible to not decrypt a frame even if a key
- * for it has been uploaded to hardware, the stack will not make any
+ * for it has been uploaded to hardware. The stack will not make any
  * decision based on whether a key has been uploaded or not but rather
  * based on the receive flags.
  *
@@ -3081,7 +3087,7 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * The update_tkip_key() call updates the driver with the new phase 1 key.
  * This happens every time the iv16 wraps around (every 65536 packets). The
  * set_key() call will happen only once for each key (unless the AP did
- * rekeying), it will not include a valid phase 1 key. The valid phase 1 key is
+ * rekeying); it will not include a valid phase 1 key. The valid phase 1 key is
  * provided by update_tkip_key only. The trigger that makes mac80211 call this
  * handler is software decryption with wrap around of iv16.
  *
@@ -3108,7 +3114,7 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  *
  * mac80211 has support for various powersave implementations.
  *
- * First, it can support hardware that handles all powersaving by itself,
+ * First, it can support hardware that handles all powersaving by itself;
  * such hardware should simply set the %IEEE80211_HW_SUPPORTS_PS hardware
  * flag. In that case, it will be told about the desired powersave mode
  * with the %IEEE80211_CONF_PS flag depending on the association status.
@@ -3133,12 +3139,12 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * %IEEE80211_HW_PS_NULLFUNC_STACK flags. The hardware is of course still
  * required to pass up beacons. The hardware is still required to handle
  * waking up for multicast traffic; if it cannot the driver must handle that
- * as best as it can, mac80211 is too slow to do that.
+ * as best as it can; mac80211 is too slow to do that.
  *
  * Dynamic powersave is an extension to normal powersave in which the
  * hardware stays awake for a user-specified period of time after sending a
  * frame so that reply frames need not be buffered and therefore delayed to
- * the next wakeup. It's compromise of getting good enough latency when
+ * the next wakeup. It's a compromise of getting good enough latency when
  * there's data traffic and still saving significantly power in idle
  * periods.
  *
@@ -3203,7 +3209,7 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * Note that change, for the sake of simplification, also includes information
  * elements appearing or disappearing from the beacon.
  *
- * Some hardware supports an "ignore list" instead, just make sure nothing
+ * Some hardware supports an "ignore list" instead. Just make sure nothing
  * that was requested is on the ignore list, and include commonly changing
  * information element IDs in the ignore list, for example 11 (BSS load) and
  * the various vendor-assigned IEs with unknown contents (128, 129, 133-136,
@@ -3214,7 +3220,7 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * In addition to these capabilities, hardware should support notifying the
  * host of changes in the beacon RSSI. This is relevant to implement roaming
  * when no traffic is flowing (when traffic is flowing we see the RSSI of
- * the received data packets). This can consist in notifying the host when
+ * the received data packets). This can consist of notifying the host when
  * the RSSI changes significantly or when it drops below or rises above
  * configurable thresholds. In the future these thresholds will also be
  * configured by mac80211 (which gets them from userspace) to implement
@@ -3361,8 +3367,8 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * period starts for any reason, @release_buffered_frames is called
  * with the number of frames to be released and which TIDs they are
  * to come from. In this case, the driver is responsible for setting
- * the EOSP (for uAPSD) and MORE_DATA bits in the released frames,
- * to help the @more_data parameter is passed to tell the driver if
+ * the EOSP (for uAPSD) and MORE_DATA bits in the released frames.
+ * To help the @more_data parameter is passed to tell the driver if
  * there is more data on other TIDs -- the TIDs to release frames
  * from are ignored since mac80211 doesn't know how many frames the
  * buffers for those TIDs contain.
@@ -3411,7 +3417,7 @@ void ieee80211_free_txskb(struct ieee80211_hw *hw, struct sk_buff *skb);
  * Additionally, the driver has to then use these HW queue IDs for the queue
  * management functions (ieee80211_stop_queue() et al.)
  *
- * The driver is free to set up the queue mappings as needed, multiple virtual
+ * The driver is free to set up the queue mappings as needed; multiple virtual
  * interfaces may map to the same hardware queues if needed. The setup has to
  * happen during add_interface or change_interface callbacks. For example, a
  * driver supporting station+station and station+AP modes might decide to have
@@ -3635,11 +3641,14 @@ enum ieee80211_reconfig_type {
  * @success: whether the frame exchange was successful, only
  *	used with the mgd_complete_tx() method, and then only
  *	valid for auth and (re)assoc.
+ * @link_id: the link id on which the frame will be TX'ed.
+ *	Only used with the mgd_prepare_tx() method.
  */
 struct ieee80211_prep_tx_info {
 	u16 duration;
 	u16 subtype;
 	u8 success:1;
+	int link_id;
 };
 
 /**
@@ -3863,6 +3872,10 @@ struct ieee80211_prep_tx_info {
  *	the station. See @sta_pre_rcu_remove if needed.
  *	This callback can sleep.
  *
+ * @vif_add_debugfs: Drivers can use this callback to add a debugfs vif
+ *	directory with its files. This callback should be within a
+ *	CONFIG_MAC80211_DEBUGFS conditional. This callback can sleep.
+ *
  * @link_add_debugfs: Drivers can use this callback to add debugfs files
  *	when a link is added to a mac80211 vif. This callback should be within
  *	a CONFIG_MAC80211_DEBUGFS conditional. This callback can sleep.
@@ -4067,11 +4080,15 @@ struct ieee80211_prep_tx_info {
  *	This callback must be atomic.
  *
  * @get_et_sset_count:  Ethtool API to get string-set count.
+ *	Note that the wiphy mutex is not held for this callback since it's
+ *	expected to return a static value.
  *
  * @get_et_stats:  Ethtool API to get a set of u64 stats.
  *
  * @get_et_strings:  Ethtool API to get a set of strings to describe stats
  *	and perhaps other supported types of ethtool data-sets.
+ *	Note that the wiphy mutex is not held for this callback since it's
+ *	expected to return a static value.
  *
  * @mgd_prepare_tx: Prepare for transmitting a management frame for association
  *	before associated. In multi-channel scenarios, a virtual interface is
@@ -4358,6 +4375,8 @@ struct ieee80211_ops {
 	int (*sta_remove)(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 			  struct ieee80211_sta *sta);
 #ifdef CONFIG_MAC80211_DEBUGFS
+	void (*vif_add_debugfs)(struct ieee80211_hw *hw,
+				struct ieee80211_vif *vif);
 	void (*link_add_debugfs)(struct ieee80211_hw *hw,
 				 struct ieee80211_vif *vif,
 				 struct ieee80211_bss_conf *link_conf,
@@ -4506,7 +4525,8 @@ struct ieee80211_ops {
 				   struct ieee80211_prep_tx_info *info);
 
 	void	(*mgd_protect_tdls_discover)(struct ieee80211_hw *hw,
-					     struct ieee80211_vif *vif);
+					     struct ieee80211_vif *vif,
+					     unsigned int link_id);
 
 	int (*add_chanctx)(struct ieee80211_hw *hw,
 			   struct ieee80211_chanctx_conf *ctx);
@@ -4544,7 +4564,8 @@ struct ieee80211_ops {
 				  struct ieee80211_channel_switch *ch_switch);
 
 	int (*post_channel_switch)(struct ieee80211_hw *hw,
-				   struct ieee80211_vif *vif);
+				   struct ieee80211_vif *vif,
+				   struct ieee80211_bss_conf *link_conf);
 	void (*abort_channel_switch)(struct ieee80211_hw *hw,
 				     struct ieee80211_vif *vif);
 	void (*channel_switch_rx_beacon)(struct ieee80211_hw *hw,
@@ -4890,7 +4911,7 @@ void ieee80211_restart_hw(struct ieee80211_hw *hw);
  * for a single hardware must be synchronized against each other. Calls to
  * this function, ieee80211_rx_ni() and ieee80211_rx_irqsafe() may not be
  * mixed for a single hardware. Must not run concurrently with
- * ieee80211_tx_status() or ieee80211_tx_status_ni().
+ * ieee80211_tx_status_skb() or ieee80211_tx_status_ni().
  *
  * This function must be called with BHs disabled and RCU read lock
  *
@@ -4915,7 +4936,7 @@ void ieee80211_rx_list(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
  * for a single hardware must be synchronized against each other. Calls to
  * this function, ieee80211_rx_ni() and ieee80211_rx_irqsafe() may not be
  * mixed for a single hardware. Must not run concurrently with
- * ieee80211_tx_status() or ieee80211_tx_status_ni().
+ * ieee80211_tx_status_skb() or ieee80211_tx_status_ni().
  *
  * This function must be called with BHs disabled.
  *
@@ -4940,7 +4961,7 @@ void ieee80211_rx_napi(struct ieee80211_hw *hw, struct ieee80211_sta *sta,
  * for a single hardware must be synchronized against each other. Calls to
  * this function, ieee80211_rx_ni() and ieee80211_rx_irqsafe() may not be
  * mixed for a single hardware. Must not run concurrently with
- * ieee80211_tx_status() or ieee80211_tx_status_ni().
+ * ieee80211_tx_status_skb() or ieee80211_tx_status_ni().
  *
  * In process context use instead ieee80211_rx_ni().
  *
@@ -4960,7 +4981,7 @@ static inline void ieee80211_rx(struct ieee80211_hw *hw, struct sk_buff *skb)
  *
  * Calls to this function, ieee80211_rx() or ieee80211_rx_ni() may not
  * be mixed for a single hardware.Must not run concurrently with
- * ieee80211_tx_status() or ieee80211_tx_status_ni().
+ * ieee80211_tx_status_skb() or ieee80211_tx_status_ni().
  *
  * @hw: the hardware this frame came in on
  * @skb: the buffer to receive, owned by mac80211 after this call
@@ -4975,7 +4996,7 @@ void ieee80211_rx_irqsafe(struct ieee80211_hw *hw, struct sk_buff *skb);
  *
  * Calls to this function, ieee80211_rx() and ieee80211_rx_irqsafe() may
  * not be mixed for a single hardware. Must not run concurrently with
- * ieee80211_tx_status() or ieee80211_tx_status_ni().
+ * ieee80211_tx_status_skb() or ieee80211_tx_status_ni().
  *
  * @hw: the hardware this frame came in on
  * @skb: the buffer to receive, owned by mac80211 after this call
@@ -5151,7 +5172,7 @@ void ieee80211_tx_rate_update(struct ieee80211_hw *hw,
 			      struct ieee80211_tx_info *info);
 
 /**
- * ieee80211_tx_status - transmit status callback
+ * ieee80211_tx_status_skb - transmit status callback
  *
  * Call this function for all transmitted frames after they have been
  * transmitted. It is permissible to not call this function for
@@ -5166,13 +5187,13 @@ void ieee80211_tx_rate_update(struct ieee80211_hw *hw,
  * @hw: the hardware the frame was transmitted by
  * @skb: the frame that was transmitted, owned by mac80211 after this call
  */
-void ieee80211_tx_status(struct ieee80211_hw *hw,
-			 struct sk_buff *skb);
+void ieee80211_tx_status_skb(struct ieee80211_hw *hw,
+			     struct sk_buff *skb);
 
 /**
  * ieee80211_tx_status_ext - extended transmit status callback
  *
- * This function can be used as a replacement for ieee80211_tx_status
+ * This function can be used as a replacement for ieee80211_tx_status_skb()
  * in drivers that may want to provide extra information that does not
  * fit into &struct ieee80211_tx_info.
  *
@@ -5189,7 +5210,7 @@ void ieee80211_tx_status_ext(struct ieee80211_hw *hw,
 /**
  * ieee80211_tx_status_noskb - transmit status callback without skb
  *
- * This function can be used as a replacement for ieee80211_tx_status
+ * This function can be used as a replacement for ieee80211_tx_status_skb()
  * in drivers that cannot reliably map tx status information back to
  * specific skbs.
  *
@@ -5217,9 +5238,9 @@ static inline void ieee80211_tx_status_noskb(struct ieee80211_hw *hw,
 /**
  * ieee80211_tx_status_ni - transmit status callback (in process context)
  *
- * Like ieee80211_tx_status() but can be called in process context.
+ * Like ieee80211_tx_status_skb() but can be called in process context.
  *
- * Calls to this function, ieee80211_tx_status() and
+ * Calls to this function, ieee80211_tx_status_skb() and
  * ieee80211_tx_status_irqsafe() may not be mixed
  * for a single hardware.
  *
@@ -5230,17 +5251,17 @@ static inline void ieee80211_tx_status_ni(struct ieee80211_hw *hw,
 					  struct sk_buff *skb)
 {
 	local_bh_disable();
-	ieee80211_tx_status(hw, skb);
+	ieee80211_tx_status_skb(hw, skb);
 	local_bh_enable();
 }
 
 /**
  * ieee80211_tx_status_irqsafe - IRQ-safe transmit status callback
  *
- * Like ieee80211_tx_status() but can be called in IRQ context
+ * Like ieee80211_tx_status_skb() but can be called in IRQ context
  * (internally defers to a tasklet.)
  *
- * Calls to this function, ieee80211_tx_status() and
+ * Calls to this function, ieee80211_tx_status_skb() and
  * ieee80211_tx_status_ni() may not be mixed for a single hardware.
  *
  * @hw: the hardware the frame was transmitted by
@@ -6542,11 +6563,14 @@ void ieee80211_radar_detected(struct ieee80211_hw *hw);
  * ieee80211_chswitch_done - Complete channel switch process
  * @vif: &struct ieee80211_vif pointer from the add_interface callback.
  * @success: make the channel switch successful or not
+ * @link_id: the link_id on which the switch was done. Ignored if success is
+ *	false.
  *
  * Complete the channel switch post-process: set the new operational channel
  * and wake up the suspended queues.
  */
-void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success);
+void ieee80211_chswitch_done(struct ieee80211_vif *vif, bool success,
+			     unsigned int link_id);
 
 /**
  * ieee80211_channel_switch_disconnect - disconnect due to channel switch error
@@ -7242,7 +7266,7 @@ ieee80211_return_txq(struct ieee80211_hw *hw, struct ieee80211_txq *txq,
  *
  * This function is used to check whether given txq is allowed to transmit by
  * the airtime scheduler, and can be used by drivers to access the airtime
- * fairness accounting without going using the scheduling order enfored by
+ * fairness accounting without using the scheduling order enforced by
  * next_txq().
  *
  * Returns %true if the airtime scheduler thinks the TXQ should be allowed to