mac80211: redefine usage of the mac80211 workqueue

The mac80211 workqueue exists to enable mac80211 and drivers
to queue their own work on a single threaded workqueue. mac80211
takes care to flush the workqueue during suspend but we never
really had requirements on drivers for how they should use
the workqueue in consideration for suspend.

We extend mac80211 to document how the mac80211 workqueue should
be used, how it should not be used and finally move raw access to
the workqueue to mac80211 only. Drivers and mac80211 use helpers
to queue work onto the mac80211 workqueue:

  * ieee80211_queue_work()
  * ieee80211_queue_delayed_work()

These helpers will now warn if mac80211 already completed its
suspend cycle and someone is trying to queue work. mac80211
flushes the mac80211 workqueue prior to suspend a few times,
but we haven't taken the care to ensure drivers won't add more
work after suspend. To help with this we add a warning when
someone tries to add work and mac80211 already completed the
suspend cycle.

Drivers should ensure they cancel any work or delayed work
in the mac80211 stop() callback.

Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/at76c50x-usb.c

@@ -1875,8 +1875,8 @@ static void at76_dwork_hw_scan(struct work_struct *work)
 	/* FIXME: add maximum time for scan to complete */
 
 	if (ret != CMD_STATUS_COMPLETE) {
-		queue_delayed_work(priv->hw->workqueue, &priv->dwork_hw_scan,
-				   SCAN_POLL_INTERVAL);
+		ieee80211_queue_delayed_work(priv->hw, &priv->dwork_hw_scan,
+					     SCAN_POLL_INTERVAL);
 		mutex_unlock(&priv->mtx);
 		return;
 	}
@@ -1937,8 +1937,8 @@ static int at76_hw_scan(struct ieee80211_hw *hw,
 		goto exit;
 	}
 
-	queue_delayed_work(priv->hw->workqueue, &priv->dwork_hw_scan,
-			   SCAN_POLL_INTERVAL);
+	ieee80211_queue_delayed_work(priv->hw, &priv->dwork_hw_scan,
+				     SCAN_POLL_INTERVAL);
 
 exit:
 	mutex_unlock(&priv->mtx);
@@ -2027,7 +2027,7 @@ static void at76_configure_filter(struct ieee80211_hw *hw,
 	} else
 		return;
 
-	queue_work(hw->workqueue, &priv->work_set_promisc);
+	ieee80211_queue_work(hw, &priv->work_set_promisc);
 }
 
 static int at76_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,

drivers/net/wireless/ath/ar9170/led.c

@@ -90,9 +90,12 @@ static void ar9170_update_leds(struct work_struct *work)
 	ar9170_set_leds_state(ar, led_val);
 	mutex_unlock(&ar->mutex);
 
-	if (rerun)
-		queue_delayed_work(ar->hw->workqueue, &ar->led_work,
-				   msecs_to_jiffies(blink_delay));
+	if (!rerun)
+		return;
+
+	ieee80211_queue_delayed_work(ar->hw,
+				     &ar->led_work,
+				     msecs_to_jiffies(blink_delay));
 }
 
 static void ar9170_led_brightness_set(struct led_classdev *led,
@@ -110,7 +113,7 @@ static void ar9170_led_brightness_set(struct led_classdev *led,
 	}
 
 	if (likely(IS_ACCEPTING_CMD(ar) && arl->toggled))
-		queue_delayed_work(ar->hw->workqueue, &ar->led_work, HZ/10);
+		ieee80211_queue_delayed_work(ar->hw, &ar->led_work, HZ/10);
 }
 
 static int ar9170_register_led(struct ar9170 *ar, int i, char *name,

drivers/net/wireless/ath/ar9170/main.c

@@ -595,10 +595,12 @@ static void ar9170_tx_janitor(struct work_struct *work)
 
 	ar9170_tx_fake_ampdu_status(ar);
 
-	if (resched)
-		queue_delayed_work(ar->hw->workqueue,
-				   &ar->tx_janitor,
-				   msecs_to_jiffies(AR9170_JANITOR_DELAY));
+	if (!resched)
+		return;
+
+	ieee80211_queue_delayed_work(ar->hw,
+				     &ar->tx_janitor,
+				     msecs_to_jiffies(AR9170_JANITOR_DELAY));
 }
 
 void ar9170_handle_command_response(struct ar9170 *ar, void *buf, u32 len)
@@ -648,7 +650,7 @@ void ar9170_handle_command_response(struct ar9170 *ar, void *buf, u32 len)
 		 * pre-TBTT event
 		 */
 		if (ar->vif && ar->vif->type == NL80211_IFTYPE_AP)
-			queue_work(ar->hw->workqueue, &ar->beacon_work);
+			ieee80211_queue_work(ar->hw, &ar->beacon_work);
 		break;
 
 	case 0xc2:
@@ -1825,10 +1827,12 @@ static void ar9170_tx(struct ar9170 *ar)
 		}
 	}
 
-	if (schedule_garbagecollector)
-		queue_delayed_work(ar->hw->workqueue,
-				   &ar->tx_janitor,
-				   msecs_to_jiffies(AR9170_JANITOR_DELAY));
+	if (!schedule_garbagecollector)
+		return;
+
+	ieee80211_queue_delayed_work(ar->hw,
+				     &ar->tx_janitor,
+				     msecs_to_jiffies(AR9170_JANITOR_DELAY));
 }
 
 static bool ar9170_tx_ampdu_queue(struct ar9170 *ar, struct sk_buff *skb)
@@ -2157,7 +2161,7 @@ static void ar9170_op_configure_filter(struct ieee80211_hw *hw,
 	}
 
 	if (likely(IS_STARTED(ar)))
-		queue_work(ar->hw->workqueue, &ar->filter_config_work);
+		ieee80211_queue_work(ar->hw, &ar->filter_config_work);
 }
 
 static void ar9170_op_bss_info_changed(struct ieee80211_hw *hw,
@@ -2415,7 +2419,7 @@ static void ar9170_sta_notify(struct ieee80211_hw *hw,
 	}
 
 	if (IS_STARTED(ar) && ar->filter_changed)
-		queue_work(ar->hw->workqueue, &ar->filter_config_work);
+		ieee80211_queue_work(ar->hw, &ar->filter_config_work);
 }
 
 static int ar9170_get_stats(struct ieee80211_hw *hw,

drivers/net/wireless/ath/ath9k/main.c

@@ -973,10 +973,11 @@ static void ath_led_blink_work(struct work_struct *work)
 		ath9k_hw_set_gpio(sc->sc_ah, ATH_LED_PIN,
 				  (sc->sc_flags & SC_OP_LED_ON) ? 1 : 0);
 
-	queue_delayed_work(sc->hw->workqueue, &sc->ath_led_blink_work,
-			   (sc->sc_flags & SC_OP_LED_ON) ?
-			   msecs_to_jiffies(sc->led_off_duration) :
-			   msecs_to_jiffies(sc->led_on_duration));
+	ieee80211_queue_delayed_work(sc->hw,
+				     &sc->ath_led_blink_work,
+				     (sc->sc_flags & SC_OP_LED_ON) ?
+					msecs_to_jiffies(sc->led_off_duration) :
+					msecs_to_jiffies(sc->led_on_duration));
 
 	sc->led_on_duration = sc->led_on_cnt ?
 			max((ATH_LED_ON_DURATION_IDLE - sc->led_on_cnt), 25) :
@@ -1013,8 +1014,8 @@ static void ath_led_brightness(struct led_classdev *led_cdev,
 	case LED_FULL:
 		if (led->led_type == ATH_LED_ASSOC) {
 			sc->sc_flags |= SC_OP_LED_ASSOCIATED;
-			queue_delayed_work(sc->hw->workqueue,
-					   &sc->ath_led_blink_work, 0);
+			ieee80211_queue_delayed_work(sc->hw,
+						     &sc->ath_led_blink_work, 0);
 		} else if (led->led_type == ATH_LED_RADIO) {
 			ath9k_hw_set_gpio(sc->sc_ah, ATH_LED_PIN, 0);
 			sc->sc_flags |= SC_OP_LED_ON;
@@ -1972,7 +1973,7 @@ static int ath9k_start(struct ieee80211_hw *hw)
 
 	ieee80211_wake_queues(hw);
 
-	queue_delayed_work(sc->hw->workqueue, &sc->tx_complete_work, 0);
+	ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work, 0);
 
 mutex_unlock:
 	mutex_unlock(&sc->mutex);

drivers/net/wireless/ath/ath9k/virtual.c

@@ -351,7 +351,7 @@ void ath9k_tx_status(struct ieee80211_hw *hw, struct sk_buff *skb)
 			 * Drop from tasklet to work to allow mutex for channel
 			 * change.
 			 */
-			queue_work(aphy->sc->hw->workqueue,
+			ieee80211_queue_work(aphy->sc->hw,
 				   &aphy->sc->chan_work);
 		}
 	}
@@ -367,7 +367,7 @@ static void ath9k_mark_paused(struct ath_wiphy *aphy)
 	struct ath_softc *sc = aphy->sc;
 	aphy->state = ATH_WIPHY_PAUSED;
 	if (!__ath9k_wiphy_pausing(sc))
-		queue_work(sc->hw->workqueue, &sc->chan_work);
+		ieee80211_queue_work(sc->hw, &sc->chan_work);
 }
 
 static void ath9k_pause_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
@@ -521,7 +521,7 @@ int ath9k_wiphy_select(struct ath_wiphy *aphy)
 			spin_unlock_bh(&sc->wiphy_lock);
 			ath_radio_disable(sc);
 			ath_radio_enable(sc);
-			queue_work(aphy->sc->hw->workqueue,
+			ieee80211_queue_work(aphy->sc->hw,
 				   &aphy->sc->chan_work);
 			return -EBUSY; /* previous select still in progress */
 		}
@@ -541,7 +541,7 @@ int ath9k_wiphy_select(struct ath_wiphy *aphy)
 
 	if (now) {
 		/* Ready to request channel change immediately */
-		queue_work(aphy->sc->hw->workqueue, &aphy->sc->chan_work);
+		ieee80211_queue_work(aphy->sc->hw, &aphy->sc->chan_work);
 	}
 
 	/*
@@ -648,17 +648,18 @@ void ath9k_wiphy_work(struct work_struct *work)
 		       "change\n");
 	}
 
-	queue_delayed_work(sc->hw->workqueue, &sc->wiphy_work,
-			   sc->wiphy_scheduler_int);
+	ieee80211_queue_delayed_work(sc->hw,
+				     &sc->wiphy_work,
+				     sc->wiphy_scheduler_int);
 }
 
 void ath9k_wiphy_set_scheduler(struct ath_softc *sc, unsigned int msec_int)
 {
 	cancel_delayed_work_sync(&sc->wiphy_work);
 	sc->wiphy_scheduler_int = msecs_to_jiffies(msec_int);
 	if (sc->wiphy_scheduler_int)
-		queue_delayed_work(sc->hw->workqueue, &sc->wiphy_work,
-				   sc->wiphy_scheduler_int);
+		ieee80211_queue_delayed_work(sc->hw, &sc->wiphy_work,
+					     sc->wiphy_scheduler_int);
 }
 
 /* caller must hold wiphy_lock */

drivers/net/wireless/ath/ath9k/xmit.c

@@ -2063,7 +2063,7 @@ static void ath_tx_complete_poll_work(struct work_struct *work)
 		ath_reset(sc, false);
 	}
 
-	queue_delayed_work(sc->hw->workqueue, &sc->tx_complete_work,
+	ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work,
 			msecs_to_jiffies(ATH_TX_COMPLETE_POLL_INT));
 }
 

drivers/net/wireless/b43/main.c

@@ -1654,7 +1654,7 @@ static void b43_update_templates(struct b43_wl *wl)
 	wl->current_beacon = beacon;
 	wl->beacon0_uploaded = 0;
 	wl->beacon1_uploaded = 0;
-	queue_work(wl->hw->workqueue, &wl->beacon_update_trigger);
+	ieee80211_queue_work(wl->hw, &wl->beacon_update_trigger);
 }
 
 static void b43_set_beacon_int(struct b43_wldev *dev, u16 beacon_int)
@@ -2914,7 +2914,7 @@ static void b43_periodic_work_handler(struct work_struct *work)
 		delay = msecs_to_jiffies(50);
 	else
 		delay = round_jiffies_relative(HZ * 15);
-	queue_delayed_work(wl->hw->workqueue, &dev->periodic_work, delay);
+	ieee80211_queue_delayed_work(wl->hw, &dev->periodic_work, delay);
 out:
 	mutex_unlock(&wl->mutex);
 }
@@ -2925,7 +2925,7 @@ static void b43_periodic_tasks_setup(struct b43_wldev *dev)
 
 	dev->periodic_state = 0;
 	INIT_DELAYED_WORK(work, b43_periodic_work_handler);
-	queue_delayed_work(dev->wl->hw->workqueue, work, 0);
+	ieee80211_queue_delayed_work(dev->wl->hw, work, 0);
 }
 
 /* Check if communication with the device works correctly. */
@@ -4871,7 +4871,7 @@ void b43_controller_restart(struct b43_wldev *dev, const char *reason)
 	if (b43_status(dev) < B43_STAT_INITIALIZED)
 		return;
 	b43info(dev->wl, "Controller RESET (%s) ...\n", reason);
-	queue_work(dev->wl->hw->workqueue, &dev->restart_work);
+	ieee80211_queue_work(dev->wl->hw, &dev->restart_work);
 }
 
 #ifdef CONFIG_PM

drivers/net/wireless/b43/phy_common.c

@@ -352,7 +352,7 @@ void b43_phy_txpower_check(struct b43_wldev *dev, unsigned int flags)
 
 	/* We must adjust the transmission power in hardware.
 	 * Schedule b43_phy_txpower_adjust_work(). */
-	queue_work(dev->wl->hw->workqueue, &dev->wl->txpower_adjust_work);
+	ieee80211_queue_work(dev->wl->hw, &dev->wl->txpower_adjust_work);
 }
 
 int b43_phy_shm_tssi_read(struct b43_wldev *dev, u16 shm_offset)

drivers/net/wireless/b43/pio.c

@@ -783,7 +783,7 @@ void b43_pio_rx(struct b43_pio_rxqueue *q)
 {
 	/* Due to latency issues we must run the RX path in
 	 * a workqueue to be able to schedule between packets. */
-	queue_work(q->dev->wl->hw->workqueue, &q->rx_work);
+	ieee80211_queue_work(q->dev->wl->hw, &q->rx_work);
 }
 
 static void b43_pio_tx_suspend_queue(struct b43_pio_txqueue *q)

drivers/net/wireless/b43legacy/main.c

@@ -1252,7 +1252,7 @@ static void b43legacy_update_templates(struct b43legacy_wl *wl)
 	wl->current_beacon = beacon;
 	wl->beacon0_uploaded = 0;
 	wl->beacon1_uploaded = 0;
-	queue_work(wl->hw->workqueue, &wl->beacon_update_trigger);
+	ieee80211_queue_work(wl->hw, &wl->beacon_update_trigger);
 }
 
 static void b43legacy_set_beacon_int(struct b43legacy_wldev *dev,
@@ -2300,7 +2300,7 @@ static void b43legacy_periodic_work_handler(struct work_struct *work)
 		delay = msecs_to_jiffies(50);
 	else
 		delay = round_jiffies_relative(HZ * 15);
-	queue_delayed_work(wl->hw->workqueue, &dev->periodic_work, delay);
+	ieee80211_queue_delayed_work(wl->hw, &dev->periodic_work, delay);
 out:
 	mutex_unlock(&wl->mutex);
 }
@@ -2311,7 +2311,7 @@ static void b43legacy_periodic_tasks_setup(struct b43legacy_wldev *dev)
 
 	dev->periodic_state = 0;
 	INIT_DELAYED_WORK(work, b43legacy_periodic_work_handler);
-	queue_delayed_work(dev->wl->hw->workqueue, work, 0);
+	ieee80211_queue_delayed_work(dev->wl->hw, work, 0);
 }
 
 /* Validate access to the chip (SHM) */
@@ -3885,7 +3885,7 @@ void b43legacy_controller_restart(struct b43legacy_wldev *dev,
 	if (b43legacy_status(dev) < B43legacy_STAT_INITIALIZED)
 		return;
 	b43legacyinfo(dev->wl, "Controller RESET (%s) ...\n", reason);
-	queue_work(dev->wl->hw->workqueue, &dev->restart_work);
+	ieee80211_queue_work(dev->wl->hw, &dev->restart_work);
 }
 
 #ifdef CONFIG_PM

drivers/net/wireless/p54/led.c

@@ -61,7 +61,7 @@ static void p54_update_leds(struct work_struct *work)
 			wiphy_name(priv->hw->wiphy), err);
 
 	if (rerun)
-		queue_delayed_work(priv->hw->workqueue, &priv->led_work,
+		ieee80211_queue_delayed_work(priv->hw, &priv->led_work,
 			msecs_to_jiffies(blink_delay));
 }
 
@@ -78,8 +78,7 @@ static void p54_led_brightness_set(struct led_classdev *led_dev,
 
 	if ((brightness) && (led->registered)) {
 		led->toggled++;
-		queue_delayed_work(priv->hw->workqueue, &priv->led_work,
-				   HZ/10);
+		ieee80211_queue_delayed_work(priv->hw, &priv->led_work, HZ/10);
 	}
 }
 

drivers/net/wireless/p54/main.c

@@ -180,7 +180,7 @@ static int p54_start(struct ieee80211_hw *dev)
 		goto out;
 	}
 
-	queue_delayed_work(dev->workqueue, &priv->work, 0);
+	ieee80211_queue_delayed_work(dev, &priv->work, 0);
 
 	priv->softled_state = 0;
 	err = p54_set_leds(priv);

drivers/net/wireless/p54/p54spi.c

@@ -391,7 +391,7 @@ static irqreturn_t p54spi_interrupt(int irq, void *config)
 	struct spi_device *spi = config;
 	struct p54s_priv *priv = dev_get_drvdata(&spi->dev);
 
-	queue_work(priv->hw->workqueue, &priv->work);
+	ieee80211_queue_work(priv->hw, &priv->work);
 
 	return IRQ_HANDLED;
 }
@@ -479,7 +479,7 @@ static void p54spi_op_tx(struct ieee80211_hw *dev, struct sk_buff *skb)
 	list_add_tail(&di->tx_list, &priv->tx_pending);
 	spin_unlock_irqrestore(&priv->tx_lock, flags);
 
-	queue_work(priv->hw->workqueue, &priv->work);
+	ieee80211_queue_work(priv->hw, &priv->work);
 }
 
 static void p54spi_work(struct work_struct *work)

drivers/net/wireless/p54/txrx.c

@@ -380,7 +380,7 @@ static int p54_rx_data(struct p54_common *priv, struct sk_buff *skb)
 
 	ieee80211_rx_irqsafe(priv->hw, skb);
 
-	queue_delayed_work(priv->hw->workqueue, &priv->work,
+	ieee80211_queue_delayed_work(priv->hw, &priv->work,
 			   msecs_to_jiffies(P54_STATISTICS_UPDATE));
 
 	return -1;

drivers/net/wireless/rt2x00/rt2x00dev.c

@@ -215,7 +215,7 @@ void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
 						   rt2x00lib_beacondone_iter,
 						   rt2x00dev);
 
-	queue_work(rt2x00dev->hw->workqueue, &rt2x00dev->intf_work);
+	ieee80211_queue_work(rt2x00dev->hw, &rt2x00dev->intf_work);
 }
 EXPORT_SYMBOL_GPL(rt2x00lib_beacondone);
 

drivers/net/wireless/rt2x00/rt2x00link.c

@@ -351,8 +351,8 @@ void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
 
 	rt2x00link_reset_tuner(rt2x00dev, false);
 
-	queue_delayed_work(rt2x00dev->hw->workqueue,
-			   &link->work, LINK_TUNE_INTERVAL);
+	ieee80211_queue_delayed_work(rt2x00dev->hw,
+				     &link->work, LINK_TUNE_INTERVAL);
 }
 
 void rt2x00link_stop_tuner(struct rt2x00_dev *rt2x00dev)
@@ -461,8 +461,8 @@ static void rt2x00link_tuner(struct work_struct *work)
 	 * Increase tuner counter, and reschedule the next link tuner run.
 	 */
 	link->count++;
-	queue_delayed_work(rt2x00dev->hw->workqueue,
-			   &link->work, LINK_TUNE_INTERVAL);
+	ieee80211_queue_delayed_work(rt2x00dev->hw,
+				     &link->work, LINK_TUNE_INTERVAL);
 }
 
 void rt2x00link_register(struct rt2x00_dev *rt2x00dev)