[PATCH 2/5] rt2x00: Fix race conditions in flag handling

[PATCH 2/5] rt2x00: Fix race conditions in flag handling

[Ivo van Doorn]

Some of the flags should be accessed atomically to
prevent race conditions. The flags that are most important
are those that can change often and indicate the actual
state of the device, queue or queue entry.

The big flag rename was done to move all state flags to
the same naming type as the other rt2x00dev flags and
made sure all places where the flags were used were changed. ;)

Thanks to Stephen for most of the queue flags updates,
which fixes some of the most obvious consequences of the
race conditions. Among those the notorious:

rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.
rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.
rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.

Signed-off-by: Stephen Blackheath <tramp.enshrine.stephen@blacksapphire.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
John, please queue for 2.6.27 and 2.6.28
---
 drivers/net/wireless/rt2x00/rt2400pci.c    |    2 +-
 drivers/net/wireless/rt2x00/rt2500pci.c    |    2 +-
 drivers/net/wireless/rt2x00/rt2500usb.c    |    2 +-
 drivers/net/wireless/rt2x00/rt2x00.h       |   16 ++++----
 drivers/net/wireless/rt2x00/rt2x00config.c |    4 +-
 drivers/net/wireless/rt2x00/rt2x00dev.c    |   58 ++++++++++++++-------------
 drivers/net/wireless/rt2x00/rt2x00mac.c    |   26 ++++++------
 drivers/net/wireless/rt2x00/rt2x00queue.c  |    6 +-
 drivers/net/wireless/rt2x00/rt2x00rfkill.c |    6 +-
 drivers/net/wireless/rt2x00/rt2x00usb.c    |   10 ++--
 drivers/net/wireless/rt2x00/rt61pci.c      |    2 +-
 11 files changed, 68 insertions(+), 66 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2400pci.c b/drivers/net/wireless/rt2x00/rt2400pci.c
index 0107cec..18b703c 100644
--- a/drivers/net/wireless/rt2x00/rt2400pci.c
+++ b/drivers/net/wireless/rt2x00/rt2400pci.c
@@ -1241,7 +1241,7 @@ static irqreturn_t rt2400pci_interrupt(int irq, void *dev_instance)
 	if (!reg)
 		return IRQ_NONE;
 
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return IRQ_HANDLED;
 
 	/*
diff --git a/drivers/net/wireless/rt2x00/rt2500pci.c b/drivers/net/wireless/rt2x00/rt2500pci.c
index e0ff76f..5cc706a 100644
--- a/drivers/net/wireless/rt2x00/rt2500pci.c
+++ b/drivers/net/wireless/rt2x00/rt2500pci.c
@@ -1377,7 +1377,7 @@ static irqreturn_t rt2500pci_interrupt(int irq, void *dev_instance)
 	if (!reg)
 		return IRQ_NONE;
 
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return IRQ_HANDLED;
 
 	/*
diff --git a/drivers/net/wireless/rt2x00/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index 3b90ed6..c6be4dd 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -1297,7 +1297,7 @@ static void rt2500usb_beacondone(struct urb *urb)
 	struct queue_entry *entry = (struct queue_entry *)urb->context;
 	struct queue_entry_priv_usb_bcn *bcn_priv = entry->priv_data;
 
-	if (!test_bit(DEVICE_ENABLED_RADIO, &entry->queue->rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &entry->queue->rt2x00dev->flags))
 		return;
 
 	/*
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 7476a4e..7842524 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -629,14 +629,14 @@ enum rt2x00_flags {
 	/*
 	 * Device state flags
 	 */
-	DEVICE_PRESENT,
-	DEVICE_REGISTERED_HW,
-	DEVICE_INITIALIZED,
-	DEVICE_STARTED,
-	DEVICE_STARTED_SUSPEND,
-	DEVICE_ENABLED_RADIO,
-	DEVICE_DISABLED_RADIO_HW,
-	DEVICE_DIRTY_CONFIG,
+	DEVICE_STATE_PRESENT,
+	DEVICE_STATE_REGISTERED_HW,
+	DEVICE_STATE_INITIALIZED,
+	DEVICE_STATE_STARTED,
+	DEVICE_STATE_STARTED_SUSPEND,
+	DEVICE_STATE_ENABLED_RADIO,
+	DEVICE_STATE_DISABLED_RADIO_HW,
+	DEVICE_STATE_DIRTY_CONFIG,
 
 	/*
 	 * Driver requirements
diff --git a/drivers/net/wireless/rt2x00/rt2x00config.c b/drivers/net/wireless/rt2x00/rt2x00config.c
index ea37c79..ca051f5 100644
--- a/drivers/net/wireless/rt2x00/rt2x00config.c
+++ b/drivers/net/wireless/rt2x00/rt2x00config.c
@@ -121,7 +121,7 @@ void rt2x00lib_config_antenna(struct rt2x00_dev *rt2x00dev,
 	 * Antenna setup changes require the RX to be disabled,
 	 * else the changes will be ignored by the device.
 	 */
-	if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF_LINK);
 
 	/*
@@ -136,7 +136,7 @@ void rt2x00lib_config_antenna(struct rt2x00_dev *rt2x00dev,
 	rt2x00dev->link.ant.active.rx = libconf.ant.rx;
 	rt2x00dev->link.ant.active.tx = libconf.ant.tx;
 
-	if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON_LINK);
 }
 
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 328ff8b..330ab77 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -34,7 +34,7 @@
  */
 void rt2x00lib_reset_link_tuner(struct rt2x00_dev *rt2x00dev)
 {
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return;
 
 	/*
@@ -94,8 +94,8 @@ int rt2x00lib_enable_radio(struct rt2x00_dev *rt2x00dev)
 	 * Don't enable the radio twice.
 	 * And check if the hardware button has been disabled.
 	 */
-	if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
-	    test_bit(DEVICE_DISABLED_RADIO_HW, &rt2x00dev->flags))
+	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
+	    test_bit(DEVICE_STATE_DISABLED_RADIO_HW, &rt2x00dev->flags))
 		return 0;
 
 	/*
@@ -117,7 +117,7 @@ int rt2x00lib_enable_radio(struct rt2x00_dev *rt2x00dev)
 	rt2x00leds_led_radio(rt2x00dev, true);
 	rt2x00led_led_activity(rt2x00dev, true);
 
-	__set_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags);
+	set_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags);
 
 	/*
 	 * Enable RX.
@@ -134,7 +134,7 @@ int rt2x00lib_enable_radio(struct rt2x00_dev *rt2x00dev)
 
 void rt2x00lib_disable_radio(struct rt2x00_dev *rt2x00dev)
 {
-	if (!__test_and_clear_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_and_clear_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return;
 
 	/*
@@ -354,7 +354,7 @@ static void rt2x00lib_link_tuner(struct work_struct *work)
 	 * When the radio is shutting down we should
 	 * immediately cease all link tuning.
 	 */
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return;
 
 	/*
@@ -431,7 +431,7 @@ static void rt2x00lib_intf_scheduled_iter(void *data, u8 *mac,
 	 * note that in the spinlock protected area above the delayed_flags
 	 * have been cleared correctly.
 	 */
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return;
 
 	if (delayed_flags & DELAYED_UPDATE_BEACON)
@@ -484,7 +484,7 @@ static void rt2x00lib_beacondone_iter(void *data, u8 *mac,
 
 void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
 {
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return;
 
 	ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
@@ -572,7 +572,7 @@ void rt2x00lib_txdone(struct queue_entry *entry,
 
 	rt2x00dev->ops->lib->init_txentry(rt2x00dev, entry);
 
-	__clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
+	clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 	rt2x00queue_index_inc(entry->queue, Q_INDEX_DONE);
 
 	/*
@@ -888,7 +888,7 @@ static int rt2x00lib_probe_hw_modes(struct rt2x00_dev *rt2x00dev,
 
 static void rt2x00lib_remove_hw(struct rt2x00_dev *rt2x00dev)
 {
-	if (test_bit(DEVICE_REGISTERED_HW, &rt2x00dev->flags))
+	if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
 		ieee80211_unregister_hw(rt2x00dev->hw);
 
 	if (likely(rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ])) {
@@ -906,6 +906,9 @@ static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev)
 	struct hw_mode_spec *spec = &rt2x00dev->spec;
 	int status;
 
+	if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
+		return 0;
+
 	/*
 	 * Initialize HW modes.
 	 */
@@ -927,7 +930,7 @@ static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev)
 		return status;
 	}
 
-	__set_bit(DEVICE_REGISTERED_HW, &rt2x00dev->flags);
+	set_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags);
 
 	return 0;
 }
@@ -937,7 +940,7 @@ static int rt2x00lib_probe_hw(struct rt2x00_dev *rt2x00dev)
  */
 static void rt2x00lib_uninitialize(struct rt2x00_dev *rt2x00dev)
 {
-	if (!__test_and_clear_bit(DEVICE_INITIALIZED, &rt2x00dev->flags))
+	if (!test_and_clear_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
 		return;
 
 	/*
@@ -960,7 +963,7 @@ static int rt2x00lib_initialize(struct rt2x00_dev *rt2x00dev)
 {
 	int status;
 
-	if (test_bit(DEVICE_INITIALIZED, &rt2x00dev->flags))
+	if (test_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
 		return 0;
 
 	/*
@@ -979,7 +982,7 @@ static int rt2x00lib_initialize(struct rt2x00_dev *rt2x00dev)
 		return status;
 	}
 
-	__set_bit(DEVICE_INITIALIZED, &rt2x00dev->flags);
+	set_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags);
 
 	/*
 	 * Register the extra components.
@@ -993,7 +996,7 @@ int rt2x00lib_start(struct rt2x00_dev *rt2x00dev)
 {
 	int retval;
 
-	if (test_bit(DEVICE_STARTED, &rt2x00dev->flags))
+	if (test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
 		return 0;
 
 	/*
@@ -1024,15 +1027,15 @@ int rt2x00lib_start(struct rt2x00_dev *rt2x00dev)
 	rt2x00dev->intf_sta_count = 0;
 	rt2x00dev->intf_associated = 0;
 
-	__set_bit(DEVICE_STARTED, &rt2x00dev->flags);
-	__set_bit(DEVICE_DIRTY_CONFIG, &rt2x00dev->flags);
+	set_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags);
+	set_bit(DEVICE_STATE_DIRTY_CONFIG, &rt2x00dev->flags);
 
 	return 0;
 }
 
 void rt2x00lib_stop(struct rt2x00_dev *rt2x00dev)
 {
-	if (!test_bit(DEVICE_STARTED, &rt2x00dev->flags))
+	if (!test_and_clear_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
 		return;
 
 	/*
@@ -1044,8 +1047,6 @@ void rt2x00lib_stop(struct rt2x00_dev *rt2x00dev)
 	rt2x00dev->intf_ap_count = 0;
 	rt2x00dev->intf_sta_count = 0;
 	rt2x00dev->intf_associated = 0;
-
-	__clear_bit(DEVICE_STARTED, &rt2x00dev->flags);
 }
 
 /*
@@ -1100,7 +1101,7 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
 	rt2x00rfkill_allocate(rt2x00dev);
 	rt2x00debug_register(rt2x00dev);
 
-	__set_bit(DEVICE_PRESENT, &rt2x00dev->flags);
+	set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
 
 	return 0;
 
@@ -1113,7 +1114,7 @@ EXPORT_SYMBOL_GPL(rt2x00lib_probe_dev);
 
 void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
 {
-	__clear_bit(DEVICE_PRESENT, &rt2x00dev->flags);
+	clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
 
 	/*
 	 * Disable radio.
@@ -1158,14 +1159,15 @@ int rt2x00lib_suspend(struct rt2x00_dev *rt2x00dev, pm_message_t state)
 	int retval;
 
 	NOTICE(rt2x00dev, "Going to sleep.\n");
-	__clear_bit(DEVICE_PRESENT, &rt2x00dev->flags);
 
 	/*
 	 * Only continue if mac80211 has open interfaces.
 	 */
-	if (!test_bit(DEVICE_STARTED, &rt2x00dev->flags))
+	if (!test_and_clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
+	    !test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
 		goto exit;
-	__set_bit(DEVICE_STARTED_SUSPEND, &rt2x00dev->flags);
+
+	set_bit(DEVICE_STATE_STARTED_SUSPEND, &rt2x00dev->flags);
 
 	/*
 	 * Disable radio.
@@ -1237,7 +1239,7 @@ int rt2x00lib_resume(struct rt2x00_dev *rt2x00dev)
 	/*
 	 * Only continue if mac80211 had open interfaces.
 	 */
-	if (!__test_and_clear_bit(DEVICE_STARTED_SUSPEND, &rt2x00dev->flags))
+	if (!test_and_clear_bit(DEVICE_STATE_STARTED_SUSPEND, &rt2x00dev->flags))
 		return 0;
 
 	/*
@@ -1264,7 +1266,7 @@ int rt2x00lib_resume(struct rt2x00_dev *rt2x00dev)
 	/*
 	 * We are ready again to receive requests from mac80211.
 	 */
-	__set_bit(DEVICE_PRESENT, &rt2x00dev->flags);
+	set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
 
 	/*
 	 * It is possible that during that mac80211 has attempted
@@ -1284,7 +1286,7 @@ int rt2x00lib_resume(struct rt2x00_dev *rt2x00dev)
 	return 0;
 
 exit:
-	rt2x00lib_disable_radio(rt2x00dev);
+	rt2x00lib_stop(rt2x00dev);
 	rt2x00lib_uninitialize(rt2x00dev);
 	rt2x00debug_deregister(rt2x00dev);
 
diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c
index 3af4273..11be895 100644
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
@@ -117,7 +117,7 @@ int rt2x00mac_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
 	 * Note that we can only stop the TX queues inside the TX path
 	 * due to possible race conditions in mac80211.
 	 */
-	if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
 		goto exit_fail;
 
 	/*
@@ -175,7 +175,7 @@ int rt2x00mac_start(struct ieee80211_hw *hw)
 {
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 
-	if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
 		return 0;
 
 	return rt2x00lib_start(rt2x00dev);
@@ -186,7 +186,7 @@ void rt2x00mac_stop(struct ieee80211_hw *hw)
 {
 	struct rt2x00_dev *rt2x00dev = hw->priv;
 
-	if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
 		return;
 
 	rt2x00lib_stop(rt2x00dev);
@@ -206,8 +206,8 @@ int rt2x00mac_add_interface(struct ieee80211_hw *hw,
 	 * Don't allow interfaces to be added
 	 * the device has disappeared.
 	 */
-	if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags) ||
-	    !test_bit(DEVICE_STARTED, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
+	    !test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
 		return -ENODEV;
 
 	switch (conf->type) {
@@ -256,7 +256,7 @@ int rt2x00mac_add_interface(struct ieee80211_hw *hw,
 	 */
 	for (i = 0; i < queue->limit; i++) {
 		entry = &queue->entries[i];
-		if (!__test_and_set_bit(ENTRY_BCN_ASSIGNED, &entry->flags))
+		if (!test_and_set_bit(ENTRY_BCN_ASSIGNED, &entry->flags))
 			break;
 	}
 
@@ -310,7 +310,7 @@ void rt2x00mac_remove_interface(struct ieee80211_hw *hw,
 	 * either the device has disappeared or when
 	 * no interface is present.
 	 */
-	if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags) ||
+	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
 	    (conf->type == IEEE80211_IF_TYPE_AP && !rt2x00dev->intf_ap_count) ||
 	    (conf->type != IEEE80211_IF_TYPE_AP && !rt2x00dev->intf_sta_count))
 		return;
@@ -324,7 +324,7 @@ void rt2x00mac_remove_interface(struct ieee80211_hw *hw,
 	 * Release beacon entry so it is available for
 	 * new interfaces again.
 	 */
-	__clear_bit(ENTRY_BCN_ASSIGNED, &intf->beacon->flags);
+	clear_bit(ENTRY_BCN_ASSIGNED, &intf->beacon->flags);
 
 	/*
 	 * Make sure the bssid and mac address registers
@@ -344,14 +344,14 @@ int rt2x00mac_config(struct ieee80211_hw *hw, struct ieee80211_conf *conf)
 	 * Mac80211 might be calling this function while we are trying
 	 * to remove the device or perhaps suspending it.
 	 */
-	if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
 		return 0;
 
 	/*
 	 * Check if we need to disable the radio,
 	 * if this is not the case, at least the RX must be disabled.
 	 */
-	if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags)) {
+	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) {
 		if (!conf->radio_enabled)
 			rt2x00lib_disable_radio(rt2x00dev);
 		else
@@ -366,14 +366,14 @@ int rt2x00mac_config(struct ieee80211_hw *hw, struct ieee80211_conf *conf)
 	 * initialized.
 	 */
 	force_reconfig =
-	    __test_and_clear_bit(DEVICE_DIRTY_CONFIG, &rt2x00dev->flags);
+	    test_and_clear_bit(DEVICE_STATE_DIRTY_CONFIG, &rt2x00dev->flags);
 
 	rt2x00lib_config(rt2x00dev, conf, force_reconfig);
 
 	/*
 	 * Reenable RX only if the radio should be on.
 	 */
-	if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON);
 	else if (conf->radio_enabled)
 		return rt2x00lib_enable_radio(rt2x00dev);
@@ -395,7 +395,7 @@ int rt2x00mac_config_interface(struct ieee80211_hw *hw,
 	 * Mac80211 might be calling this function while we are trying
 	 * to remove the device or perhaps suspending it.
 	 */
-	if (!test_bit(DEVICE_PRESENT, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
 		return 0;
 
 	spin_lock(&intf->lock);
diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index c0f97c5..d10a801 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -356,7 +356,7 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb)
 	if (unlikely(rt2x00queue_full(queue)))
 		return -EINVAL;
 
-	if (__test_and_set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags)) {
+	if (test_and_set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags)) {
 		ERROR(queue->rt2x00dev,
 		      "Arrived at non-free entry in the non-full queue %d.\n"
 		      "Please file bug report to %s.\n",
@@ -396,7 +396,7 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb)
 	 * the frame to mac80211 because the skb->cb has now been tainted.
 	 */
 	if (unlikely(queue->rt2x00dev->ops->lib->write_tx_data(entry))) {
-		__clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
+		clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 		dev_kfree_skb_any(entry->skb);
 		entry->skb = NULL;
 		return 0;
@@ -405,7 +405,7 @@ int rt2x00queue_write_tx_frame(struct data_queue *queue, struct sk_buff *skb)
 	if (test_bit(DRIVER_REQUIRE_DMA, &queue->rt2x00dev->flags))
 		rt2x00queue_map_txskb(queue->rt2x00dev, skb);
 
-	__set_bit(ENTRY_DATA_PENDING, &entry->flags);
+	set_bit(ENTRY_DATA_PENDING, &entry->flags);
 
 	rt2x00queue_index_inc(queue, Q_INDEX);
 	rt2x00queue_write_tx_descriptor(entry, &txdesc);
diff --git a/drivers/net/wireless/rt2x00/rt2x00rfkill.c b/drivers/net/wireless/rt2x00/rt2x00rfkill.c
index 04b2971..8a2fefb 100644
--- a/drivers/net/wireless/rt2x00/rt2x00rfkill.c
+++ b/drivers/net/wireless/rt2x00/rt2x00rfkill.c
@@ -41,16 +41,16 @@ static int rt2x00rfkill_toggle_radio(void *data, enum rfkill_state state)
 	/*
 	 * Only continue if there are enabled interfaces.
 	 */
-	if (!test_bit(DEVICE_STARTED, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
 		return 0;
 
 	if (state == RFKILL_STATE_UNBLOCKED) {
 		INFO(rt2x00dev, "Hardware button pressed, enabling radio.\n");
-		__clear_bit(DEVICE_DISABLED_RADIO_HW, &rt2x00dev->flags);
+		clear_bit(DEVICE_STATE_DISABLED_RADIO_HW, &rt2x00dev->flags);
 		retval = rt2x00lib_enable_radio(rt2x00dev);
 	} else if (state == RFKILL_STATE_SOFT_BLOCKED) {
 		INFO(rt2x00dev, "Hardware button pressed, disabling radio.\n");
-		__set_bit(DEVICE_DISABLED_RADIO_HW, &rt2x00dev->flags);
+		set_bit(DEVICE_STATE_DISABLED_RADIO_HW, &rt2x00dev->flags);
 		rt2x00lib_disable_radio(rt2x00dev);
 	} else {
 		WARNING(rt2x00dev, "Received unexpected rfkill state %d.\n",
diff --git a/drivers/net/wireless/rt2x00/rt2x00usb.c b/drivers/net/wireless/rt2x00/rt2x00usb.c
index 2050227..2dd7c83 100644
--- a/drivers/net/wireless/rt2x00/rt2x00usb.c
+++ b/drivers/net/wireless/rt2x00/rt2x00usb.c
@@ -163,7 +163,7 @@ static void rt2x00usb_interrupt_txdone(struct urb *urb)
 	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
 	struct txdone_entry_desc txdesc;
 
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
 	    !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 		return;
 
@@ -232,7 +232,7 @@ static inline void rt2x00usb_kick_tx_entry(struct queue_entry *entry)
 {
 	struct queue_entry_priv_usb *entry_priv = entry->priv_data;
 
-	if (__test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
+	if (test_and_clear_bit(ENTRY_DATA_PENDING, &entry->flags))
 		usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
 }
 
@@ -283,7 +283,7 @@ static void rt2x00usb_interrupt_rxdone(struct urb *urb)
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);
 	u8 rxd[32];
 
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
 	    !test_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags))
 		return;
 
@@ -293,7 +293,7 @@ static void rt2x00usb_interrupt_rxdone(struct urb *urb)
 	 * a problem.
 	 */
 	if (urb->actual_length < entry->queue->desc_size || urb->status) {
-		__set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
+		set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 		usb_submit_urb(urb, GFP_ATOMIC);
 		return;
 	}
@@ -361,7 +361,7 @@ void rt2x00usb_init_rxentry(struct rt2x00_dev *rt2x00dev,
 			  entry->skb->data, entry->skb->len,
 			  rt2x00usb_interrupt_rxdone, entry);
 
-	__set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
+	set_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
 	usb_submit_urb(entry_priv->urb, GFP_ATOMIC);
 }
 EXPORT_SYMBOL_GPL(rt2x00usb_init_rxentry);
diff --git a/drivers/net/wireless/rt2x00/rt61pci.c b/drivers/net/wireless/rt2x00/rt61pci.c
index 00decc7..a531704 100644
--- a/drivers/net/wireless/rt2x00/rt61pci.c
+++ b/drivers/net/wireless/rt2x00/rt61pci.c
@@ -2107,7 +2107,7 @@ static irqreturn_t rt61pci_interrupt(int irq, void *dev_instance)
 	if (!reg && !reg_mcu)
 		return IRQ_NONE;
 
-	if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		return IRQ_HANDLED;
 
 	/*
-- 
1.5.6.1

[PATCH 3/5] rt2x00: Map extra_tx_headroom to DMA

[Ivo van Doorn]

If a driver requests additional headroom it should
be mapped to DMA as well because it will be send to
the hardware as well (as form of extra descriptor).

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
John, this one is for 2.6.28
---
 drivers/net/wireless/rt2x00/rt2x00queue.c |   24 +++++++++++++++++++++---
 1 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index d10a801..2822684 100644
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -100,8 +100,21 @@ void rt2x00queue_map_txskb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
 {
 	struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
 
-	skbdesc->skb_dma = dma_map_single(rt2x00dev->dev, skb->data, skb->len,
-					  DMA_TO_DEVICE);
+	/*
+	 * If device has requested headroom, we should make sure that
+	 * is also mapped to the DMA so it can be used for transfering
+	 * additional descriptor information to the hardware.
+	 */
+	skb_push(skb, rt2x00dev->hw->extra_tx_headroom);
+
+	skbdesc->skb_dma =
+	    dma_map_single(rt2x00dev->dev, skb->data, skb->len, DMA_TO_DEVICE);
+
+	/*
+	 * Restore data pointer to original location again.
+	 */
+	skb_pull(skb, rt2x00dev->hw->extra_tx_headroom);
+
 	skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
 }
 EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);
@@ -117,7 +130,12 @@ void rt2x00queue_unmap_skb(struct rt2x00_dev *rt2x00dev, struct sk_buff *skb)
 	}
 
 	if (skbdesc->flags & SKBDESC_DMA_MAPPED_TX) {
-		dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma, skb->len,
+		/*
+		 * Add headroom to the skb length, it has been removed
+		 * by the driver, but it was actually mapped to DMA.
+		 */
+		dma_unmap_single(rt2x00dev->dev, skbdesc->skb_dma,
+				 skb->len + rt2x00dev->hw->extra_tx_headroom,
 				 DMA_TO_DEVICE);
 		skbdesc->flags &= ~SKBDESC_DMA_MAPPED_TX;
 	}
-- 
1.5.6.1

[PATCH 4/5] rt2x00: Only configure hardware when radio is enabled

[Ivo van Doorn]

From: Mattias Nissler <mattias.nissler@gmx.de>

Some hardware configuration registers such as antenna and channel configuration
can only be written when the radio is enabled. Previously, we didn't consider
this, so some configuration items could be set inconsistently after reenabling
the radio. This patch changes the config() handler to only reprogram the
hardware when the radio is enabled. Configuration changes that are made while
the radio is off are postponed until the radio is switched back on. We also
leave the radio turned off during initialization and only enable it when
requested by mac80211. This allows us to get rid of the DIRTY_CONFIG flag,
because the device is now guaranteed to be completely initialized when brought
up by mac80211.

Signed-off-by: Mattias Nissler <mattias.nissler@gmx.de>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
John, please queue for 2.6.27 and 2.6.28
---
 drivers/net/wireless/rt2x00/rt2x00.h    |    1 -
 drivers/net/wireless/rt2x00/rt2x00dev.c |   10 ------
 drivers/net/wireless/rt2x00/rt2x00mac.c |   50 +++++++++++++++---------------
 3 files changed, 25 insertions(+), 36 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 7842524..0a6f35e 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -636,7 +636,6 @@ enum rt2x00_flags {
 	DEVICE_STATE_STARTED_SUSPEND,
 	DEVICE_STATE_ENABLED_RADIO,
 	DEVICE_STATE_DISABLED_RADIO_HW,
-	DEVICE_STATE_DIRTY_CONFIG,
 
 	/*
 	 * Driver requirements
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 330ab77..5278ae2 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -1014,21 +1014,11 @@ int rt2x00lib_start(struct rt2x00_dev *rt2x00dev)
 	if (retval)
 		return retval;
 
-	/*
-	 * Enable radio.
-	 */
-	retval = rt2x00lib_enable_radio(rt2x00dev);
-	if (retval) {
-		rt2x00lib_uninitialize(rt2x00dev);
-		return retval;
-	}
-
 	rt2x00dev->intf_ap_count = 0;
 	rt2x00dev->intf_sta_count = 0;
 	rt2x00dev->intf_associated = 0;
 
 	set_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags);
-	set_bit(DEVICE_STATE_DIRTY_CONFIG, &rt2x00dev->flags);
 
 	return 0;
 }
diff --git a/drivers/net/wireless/rt2x00/rt2x00mac.c b/drivers/net/wireless/rt2x00/rt2x00mac.c
index 11be895..64292c2 100644
--- a/drivers/net/wireless/rt2x00/rt2x00mac.c
+++ b/drivers/net/wireless/rt2x00/rt2x00mac.c
@@ -338,7 +338,8 @@ EXPORT_SYMBOL_GPL(rt2x00mac_remove_interface);
 int rt2x00mac_config(struct ieee80211_hw *hw, struct ieee80211_conf *conf)
 {
 	struct rt2x00_dev *rt2x00dev = hw->priv;
-	int force_reconfig;
+	int radio_on;
+	int status;
 
 	/*
 	 * Mac80211 might be calling this function while we are trying
@@ -348,35 +349,34 @@ int rt2x00mac_config(struct ieee80211_hw *hw, struct ieee80211_conf *conf)
 		return 0;
 
 	/*
-	 * Check if we need to disable the radio,
-	 * if this is not the case, at least the RX must be disabled.
+	 * Only change device state when the radio is enabled. It does not
+	 * matter what parameters we have configured when the radio is disabled
+	 * because we won't be able to send or receive anyway. Also note that
+	 * some configuration parameters (e.g. channel and antenna values) can
+	 * only be set when the radio is enabled.
 	 */
-	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags)) {
-		if (!conf->radio_enabled)
-			rt2x00lib_disable_radio(rt2x00dev);
-		else
-			rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF);
-	}
+	radio_on = test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags);
+	if (conf->radio_enabled) {
+		/* For programming the values, we have to turn RX off */
+		rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF);
 
-	/*
-	 * When the DEVICE_DIRTY_CONFIG flag is set, the device has recently
-	 * been started and the configuration must be forced upon the hardware.
-	 * Otherwise registers will not be intialized correctly and could
-	 * result in non-working hardware because essential registers aren't
-	 * initialized.
-	 */
-	force_reconfig =
-	    test_and_clear_bit(DEVICE_STATE_DIRTY_CONFIG, &rt2x00dev->flags);
+		/* Enable the radio */
+		status = rt2x00lib_enable_radio(rt2x00dev);
+		if (unlikely(status))
+			return status;
 
-	rt2x00lib_config(rt2x00dev, conf, force_reconfig);
+		/*
+		 * When we've just turned on the radio, we want to reprogram
+		 * everything to ensure a consistent state
+		 */
+		rt2x00lib_config(rt2x00dev, conf, !radio_on);
 
-	/*
-	 * Reenable RX only if the radio should be on.
-	 */
-	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
+		/* Turn RX back on */
 		rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON);
-	else if (conf->radio_enabled)
-		return rt2x00lib_enable_radio(rt2x00dev);
+	} else {
+		/* Disable the radio */
+		rt2x00lib_disable_radio(rt2x00dev);
+	}
 
 	return 0;
 }
-- 
1.5.6.1

[PATCH 5/5] rt2x00: Need to set wiphy->interface_modes

[Ivo van Doorn]

From: Stephen Blackheath <tramp.enshrine.stephen@blacksapphire.com>

One day I will understand the patching process. This patch is needed to
meet a requirement of Linux 2.6.27 drivers. Without it, userspace fails
to set the device to AP mode.

Signed-off-by: Stephen Blackheath <tramp.enshrine.stephen@blacksapphire.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
---
John, this one is for 2.6.28
---
 drivers/net/wireless/rt2x00/rt2x00dev.c |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 5278ae2..b363fad 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -1052,6 +1052,11 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
 	 */
 	rt2x00dev->hw->vif_data_size = sizeof(struct rt2x00_intf);
 
+	rt2x00dev->hw->wiphy->interface_modes =
+	    BIT(NL80211_IFTYPE_AP) |
+	    BIT(NL80211_IFTYPE_STATION) |
+	    BIT(NL80211_IFTYPE_ADHOC);
+
 	/*
 	 * Let the driver probe the device to detect the capabilities.
 	 */
-- 
1.5.6.1