rt2x00: Add autowake support for USB hardware

The USB drivers don't support automatically waking up when in powersaving mode,
add a work object which will wakeup the device in time to receive the next beacon.
Based on that beacon, we either go back into powersaving mode, or we remain awake
to receive the buffered frames for our station.

Some part of the code, especially rt2x00lib_find_ie and rt2x00lib_rxdone_check_ps
are inspired on the code from carl9170.

Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 31 insertions, 0 deletions

diff --git a/drivers/net/wireless/rt2x00/rt2x00config.c b/drivers/net/wireless/rt2x00/rt2x00config.c
index 2a313b6d378d..edebbf04bc57 100644
--- a/drivers/net/wireless/rt2x00/rt2x00config.c
+++ b/drivers/net/wireless/rt2x00/rt2x00config.c
@@ -100,6 +100,10 @@ void rt2x00lib_config_erp(struct rt2x00_dev *rt2x00dev,
 	erp.basic_rates = bss_conf->basic_rates;
 	erp.beacon_int = bss_conf->beacon_int;
 
+	/* Update the AID, this is needed for dynamic PS support */
+	rt2x00dev->aid = bss_conf->assoc ? bss_conf->aid : 0;
+	rt2x00dev->last_beacon = bss_conf->timestamp;
+
 	/* Update global beacon interval time, this is needed for PS support */
 	rt2x00dev->beacon_int = bss_conf->beacon_int;
 
@@ -204,6 +208,9 @@ void rt2x00lib_config(struct rt2x00_dev *rt2x00dev,
 {
 	struct rt2x00lib_conf libconf;
 	u16 hw_value;
+	u16 autowake_timeout;
+	u16 beacon_int;
+	u16 beacon_diff;
 
 	memset(&libconf, 0, sizeof(libconf));
 
@@ -227,6 +234,10 @@ void rt2x00lib_config(struct rt2x00_dev *rt2x00dev,
 		       sizeof(libconf.channel));
 	}
 
+	if (test_bit(REQUIRE_PS_AUTOWAKE, &rt2x00dev->cap_flags) &&
+	    (ieee80211_flags & IEEE80211_CONF_CHANGE_PS))
+		cancel_delayed_work_sync(&rt2x00dev->autowakeup_work);
+
 	/*
 	 * Start configuration.
 	 */
@@ -239,6 +250,26 @@ void rt2x00lib_config(struct rt2x00_dev *rt2x00dev,
 	if (ieee80211_flags & IEEE80211_CONF_CHANGE_CHANNEL)
 		rt2x00link_reset_tuner(rt2x00dev, false);
 
+	if (test_bit(REQUIRE_PS_AUTOWAKE, &rt2x00dev->cap_flags) &&
+	    (ieee80211_flags & IEEE80211_CONF_CHANGE_PS) &&
+	    (conf->flags & IEEE80211_CONF_PS)) {
+		beacon_diff = (long)jiffies - (long)rt2x00dev->last_beacon;
+		beacon_int = msecs_to_jiffies(rt2x00dev->beacon_int);
+
+		if (beacon_diff > beacon_int)
+			beacon_diff = 0;
+
+		autowake_timeout = (conf->max_sleep_period * beacon_int) - beacon_diff;
+		queue_delayed_work(rt2x00dev->workqueue,
+				   &rt2x00dev->autowakeup_work,
+				   autowake_timeout - 15);
+	}
+
+	if (conf->flags & IEEE80211_CONF_PS)
+		set_bit(CONFIG_POWERSAVING, &rt2x00dev->flags);
+	else
+		clear_bit(CONFIG_POWERSAVING, &rt2x00dev->flags);
+
 	rt2x00dev->curr_band = conf->channel->band;
 	rt2x00dev->curr_freq = conf->channel->center_freq;
 	rt2x00dev->tx_power = conf->power_level;