rt2x00: Disable link tuning while scanning

While scanning the link tuner must be disabled. Otherwise
it will interfere with receiving all beacons for each channel
due to changing sensitivity levels.
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/rt2x00/rt2400pci.c

@@ -1567,6 +1567,8 @@ static const struct ieee80211_ops rt2400pci_mac80211_ops = {
 	.config			= rt2x00mac_config,
 	.configure_filter	= rt2x00mac_configure_filter,
 	.set_tim		= rt2x00mac_set_tim,
+	.sw_scan_start		= rt2x00mac_sw_scan_start,
+	.sw_scan_complete	= rt2x00mac_sw_scan_complete,
 	.get_stats		= rt2x00mac_get_stats,
 	.bss_info_changed	= rt2x00mac_bss_info_changed,
 	.conf_tx		= rt2400pci_conf_tx,

drivers/net/wireless/rt2x00/rt2500pci.c

@@ -1864,6 +1864,8 @@ static const struct ieee80211_ops rt2500pci_mac80211_ops = {
 	.config			= rt2x00mac_config,
 	.configure_filter	= rt2x00mac_configure_filter,
 	.set_tim		= rt2x00mac_set_tim,
+	.sw_scan_start		= rt2x00mac_sw_scan_start,
+	.sw_scan_complete	= rt2x00mac_sw_scan_complete,
 	.get_stats		= rt2x00mac_get_stats,
 	.bss_info_changed	= rt2x00mac_bss_info_changed,
 	.conf_tx		= rt2x00mac_conf_tx,

drivers/net/wireless/rt2x00/rt2500usb.c

@@ -1755,6 +1755,8 @@ static const struct ieee80211_ops rt2500usb_mac80211_ops = {
 	.configure_filter	= rt2x00mac_configure_filter,
 	.set_tim		= rt2x00mac_set_tim,
 	.set_key		= rt2x00mac_set_key,
+	.sw_scan_start		= rt2x00mac_sw_scan_start,
+	.sw_scan_complete	= rt2x00mac_sw_scan_complete,
 	.get_stats		= rt2x00mac_get_stats,
 	.bss_info_changed	= rt2x00mac_bss_info_changed,
 	.conf_tx		= rt2x00mac_conf_tx,

drivers/net/wireless/rt2x00/rt2800lib.c

@@ -2896,6 +2896,8 @@ const struct ieee80211_ops rt2800_mac80211_ops = {
 	.configure_filter	= rt2x00mac_configure_filter,
 	.set_tim		= rt2x00mac_set_tim,
 	.set_key		= rt2x00mac_set_key,
+	.sw_scan_start		= rt2x00mac_sw_scan_start,
+	.sw_scan_complete	= rt2x00mac_sw_scan_complete,
 	.get_stats		= rt2x00mac_get_stats,
 	.get_tkip_seq		= rt2800_get_tkip_seq,
 	.set_rts_threshold	= rt2800_set_rts_threshold,

drivers/net/wireless/rt2x00/rt2x00.h

@@ -628,6 +628,7 @@ enum rt2x00_flags {
 	DEVICE_STATE_INITIALIZED,
 	DEVICE_STATE_STARTED,
 	DEVICE_STATE_ENABLED_RADIO,
+	DEVICE_STATE_SCANNING,
 
 	/*
 	 * Driver requirements
@@ -1081,6 +1082,8 @@ int rt2x00mac_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 #else
 #define rt2x00mac_set_key	NULL
 #endif /* CONFIG_RT2X00_LIB_CRYPTO */
+void rt2x00mac_sw_scan_start(struct ieee80211_hw *hw);
+void rt2x00mac_sw_scan_complete(struct ieee80211_hw *hw);
 int rt2x00mac_get_stats(struct ieee80211_hw *hw,
 			struct ieee80211_low_level_stats *stats);
 void rt2x00mac_bss_info_changed(struct ieee80211_hw *hw,

drivers/net/wireless/rt2x00/rt2x00link.c

@@ -278,6 +278,15 @@ void rt2x00link_start_tuner(struct rt2x00_dev *rt2x00dev)
 	if (!rt2x00dev->intf_sta_count)
 		return;
 
+	/**
+	 * While scanning, link tuning is disabled. By default
+	 * the most sensitive settings will be used to make sure
+	 * that all beacons and probe responses will be recieved
+	 * during the scan.
+	 */
+	if (test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
+		return;
+
 	rt2x00link_reset_tuner(rt2x00dev, false);
 
 	if (test_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags))
@@ -338,7 +347,8 @@ static void rt2x00link_tuner(struct work_struct *work)
 	 * When the radio is shutting down we should
 	 * immediately cease all link tuning.
 	 */
-	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
+	if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
+	    test_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags))
 		return;
 
 	/*

drivers/net/wireless/rt2x00/rt2x00mac.c

@@ -347,9 +347,11 @@ int rt2x00mac_config(struct ieee80211_hw *hw, u32 changed)
 	/*
 	 * Some configuration parameters (e.g. channel and antenna values) can
 	 * only be set when the radio is enabled, but do require the RX to
-	 * be off.
+	 * be off. During this period we should keep link tuning enabled,
+	 * if for any reason the link tuner must be reset, this will be
+	 * handled by rt2x00lib_config().
 	 */
-	rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF);
+	rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_OFF_LINK);
 
 	/*
 	 * When we've just turned on the radio, we want to reprogram
@@ -367,7 +369,7 @@ int rt2x00mac_config(struct ieee80211_hw *hw, u32 changed)
 	rt2x00lib_config_antenna(rt2x00dev, rt2x00dev->default_ant);
 
 	/* Turn RX back on */
-	rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON);
+	rt2x00lib_toggle_rx(rt2x00dev, STATE_RADIO_RX_ON_LINK);
 
 	return 0;
 }
@@ -540,6 +542,22 @@ int rt2x00mac_set_key(struct ieee80211_hw *hw, enum set_key_cmd cmd,
 EXPORT_SYMBOL_GPL(rt2x00mac_set_key);
 #endif /* CONFIG_RT2X00_LIB_CRYPTO */
 
+void rt2x00mac_sw_scan_start(struct ieee80211_hw *hw)
+{
+	struct rt2x00_dev *rt2x00dev = hw->priv;
+	__set_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags);
+	rt2x00link_stop_tuner(rt2x00dev);
+}
+EXPORT_SYMBOL_GPL(rt2x00mac_sw_scan_start);
+
+void rt2x00mac_sw_scan_complete(struct ieee80211_hw *hw)
+{
+	struct rt2x00_dev *rt2x00dev = hw->priv;
+	__clear_bit(DEVICE_STATE_SCANNING, &rt2x00dev->flags);
+	rt2x00link_start_tuner(rt2x00dev);
+}
+EXPORT_SYMBOL_GPL(rt2x00mac_sw_scan_complete);
+
 int rt2x00mac_get_stats(struct ieee80211_hw *hw,
 			struct ieee80211_low_level_stats *stats)
 {

drivers/net/wireless/rt2x00/rt61pci.c

@@ -2784,6 +2784,8 @@ static const struct ieee80211_ops rt61pci_mac80211_ops = {
 	.configure_filter	= rt2x00mac_configure_filter,
 	.set_tim		= rt2x00mac_set_tim,
 	.set_key		= rt2x00mac_set_key,
+	.sw_scan_start		= rt2x00mac_sw_scan_start,
+	.sw_scan_complete	= rt2x00mac_sw_scan_complete,
 	.get_stats		= rt2x00mac_get_stats,
 	.bss_info_changed	= rt2x00mac_bss_info_changed,
 	.conf_tx		= rt61pci_conf_tx,

drivers/net/wireless/rt2x00/rt73usb.c

@@ -2229,6 +2229,8 @@ static const struct ieee80211_ops rt73usb_mac80211_ops = {
 	.configure_filter	= rt2x00mac_configure_filter,
 	.set_tim		= rt2x00mac_set_tim,
 	.set_key		= rt2x00mac_set_key,
+	.sw_scan_start		= rt2x00mac_sw_scan_start,
+	.sw_scan_complete	= rt2x00mac_sw_scan_complete,
 	.get_stats		= rt2x00mac_get_stats,
 	.bss_info_changed	= rt2x00mac_bss_info_changed,
 	.conf_tx		= rt73usb_conf_tx,