rt2x00: Implement tx_frames_pending mac80211 callback function.

Implementing this callback function will cause mac80211 refrain from
going to powersave state when there are still untransmitted TX frames
in the queues.
This would exactly mimic the behaviour of the legacy vendor driver which
also doesn't go in powersave mode if there are still TX frames that are not
transmitted.
This should make powersaving and rt2x00 a better couple.

Signed-off-by: Gertjan van Wingerde <[e-mail]>
Acked-by: Helmut Schaa <[e-mail]>
Signed-off-by: Ivo van Doorn <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

drivers/net/wireless/rt2x00/rt2400pci.c

···
 	.set_antenna		= rt2x00mac_set_antenna,
 	.get_antenna		= rt2x00mac_get_antenna,
 	.get_ringparam		= rt2x00mac_get_ringparam,
+	.tx_frames_pending	= rt2x00mac_tx_frames_pending,
 };
 
 static const struct rt2x00lib_ops rt2400pci_rt2x00_ops = {

drivers/net/wireless/rt2x00/rt2500pci.c

···
 	.set_antenna		= rt2x00mac_set_antenna,
 	.get_antenna		= rt2x00mac_get_antenna,
 	.get_ringparam		= rt2x00mac_get_ringparam,
+	.tx_frames_pending	= rt2x00mac_tx_frames_pending,
 };
 
 static const struct rt2x00lib_ops rt2500pci_rt2x00_ops = {

drivers/net/wireless/rt2x00/rt2500usb.c

···
 	.set_antenna		= rt2x00mac_set_antenna,
 	.get_antenna		= rt2x00mac_get_antenna,
 	.get_ringparam		= rt2x00mac_get_ringparam,
+	.tx_frames_pending	= rt2x00mac_tx_frames_pending,
 };
 
 static const struct rt2x00lib_ops rt2500usb_rt2x00_ops = {

drivers/net/wireless/rt2x00/rt2800pci.c

···
 	.flush			= rt2x00mac_flush,
 	.get_survey		= rt2800_get_survey,
 	.get_ringparam		= rt2x00mac_get_ringparam,
+	.tx_frames_pending	= rt2x00mac_tx_frames_pending,
 };
 
 static const struct rt2800_ops rt2800pci_rt2800_ops = {

drivers/net/wireless/rt2x00/rt2800usb.c

···
 	.flush			= rt2x00mac_flush,
 	.get_survey		= rt2800_get_survey,
 	.get_ringparam		= rt2x00mac_get_ringparam,
+	.tx_frames_pending	= rt2x00mac_tx_frames_pending,
 };
 
 static const struct rt2800_ops rt2800usb_rt2800_ops = {

drivers/net/wireless/rt2x00/rt2x00.h

···
 int rt2x00mac_get_antenna(struct ieee80211_hw *hw, u32 *tx_ant, u32 *rx_ant);
 void rt2x00mac_get_ringparam(struct ieee80211_hw *hw,
 			     u32 *tx, u32 *tx_max, u32 *rx, u32 *rx_max);
+bool rt2x00mac_tx_frames_pending(struct ieee80211_hw *hw);
 
 /*
  * Driver allocation handlers.

drivers/net/wireless/rt2x00/rt2x00mac.c

···
 	*rx_max = rt2x00dev->rx->limit;
 }
 EXPORT_SYMBOL_GPL(rt2x00mac_get_ringparam);
+
+bool rt2x00mac_tx_frames_pending(struct ieee80211_hw *hw)
+{
+	struct rt2x00_dev *rt2x00dev = hw->priv;
+	struct data_queue *queue;
+
+	tx_queue_for_each(rt2x00dev, queue) {
+		if (!rt2x00queue_empty(queue))
+			return true;
+	}
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(rt2x00mac_tx_frames_pending);

drivers/net/wireless/rt2x00/rt61pci.c

···
 	.set_antenna		= rt2x00mac_set_antenna,
 	.get_antenna		= rt2x00mac_get_antenna,
 	.get_ringparam		= rt2x00mac_get_ringparam,
+	.tx_frames_pending	= rt2x00mac_tx_frames_pending,
 };
 
 static const struct rt2x00lib_ops rt61pci_rt2x00_ops = {

drivers/net/wireless/rt2x00/rt73usb.c

···
 	.set_antenna		= rt2x00mac_set_antenna,
 	.get_antenna		= rt2x00mac_get_antenna,
 	.get_ringparam		= rt2x00mac_get_ringparam,
+	.tx_frames_pending	= rt2x00mac_tx_frames_pending,
 };
 
 static const struct rt2x00lib_ops rt73usb_rt2x00_ops = {