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>
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 7776d9f..2eb5196 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -141,6 +141,16 @@
rt2x00dev);
}
+static void rt2x00lib_autowakeup(struct work_struct *work)
+{
+ struct rt2x00_dev *rt2x00dev =
+ container_of(work, struct rt2x00_dev, autowakeup_work.work);
+
+ if (rt2x00dev->ops->lib->set_device_state(rt2x00dev, STATE_AWAKE))
+ ERROR(rt2x00dev, "Device failed to wakeup.\n");
+ clear_bit(CONFIG_POWERSAVING, &rt2x00dev->flags);
+}
+
/*
* Interrupt context handlers.
*/
@@ -416,6 +426,77 @@
}
EXPORT_SYMBOL_GPL(rt2x00lib_txdone_noinfo);
+static u8 *rt2x00lib_find_ie(u8 *data, unsigned int len, u8 ie)
+{
+ struct ieee80211_mgmt *mgmt = (void *)data;
+ u8 *pos, *end;
+
+ pos = (u8 *)mgmt->u.beacon.variable;
+ end = data + len;
+ while (pos < end) {
+ if (pos + 2 + pos[1] > end)
+ return NULL;
+
+ if (pos[0] == ie)
+ return pos;
+
+ pos += 2 + pos[1];
+ }
+
+ return NULL;
+}
+
+static void rt2x00lib_rxdone_check_ps(struct rt2x00_dev *rt2x00dev,
+ struct sk_buff *skb,
+ struct rxdone_entry_desc *rxdesc)
+{
+ struct ieee80211_hdr *hdr = (void *) skb->data;
+ struct ieee80211_tim_ie *tim_ie;
+ u8 *tim;
+ u8 tim_len;
+ bool cam;
+
+ /* If this is not a beacon, or if mac80211 has no powersaving
+ * configured, or if the device is already in powersaving mode
+ * we can exit now. */
+ if (likely(!ieee80211_is_beacon(hdr->frame_control) ||
+ !(rt2x00dev->hw->conf.flags & IEEE80211_CONF_PS)))
+ return;
+
+ /* min. beacon length + FCS_LEN */
+ if (skb->len <= 40 + FCS_LEN)
+ return;
+
+ /* and only beacons from the associated BSSID, please */
+ if (!(rxdesc->dev_flags & RXDONE_MY_BSS) ||
+ !rt2x00dev->aid)
+ return;
+
+ rt2x00dev->last_beacon = jiffies;
+
+ tim = rt2x00lib_find_ie(skb->data, skb->len - FCS_LEN, WLAN_EID_TIM);
+ if (!tim)
+ return;
+
+ if (tim[1] < sizeof(*tim_ie))
+ return;
+
+ tim_len = tim[1];
+ tim_ie = (struct ieee80211_tim_ie *) &tim[2];
+
+ /* Check whenever the PHY can be turned off again. */
+
+ /* 1. What about buffered unicast traffic for our AID? */
+ cam = ieee80211_check_tim(tim_ie, tim_len, rt2x00dev->aid);
+
+ /* 2. Maybe the AP wants to send multicast/broadcast data? */
+ cam |= (tim_ie->bitmap_ctrl & 0x01);
+
+ if (!cam && !test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags))
+ rt2x00lib_config(rt2x00dev, &rt2x00dev->hw->conf,
+ IEEE80211_CONF_CHANGE_PS);
+}
+
static int rt2x00lib_rxdone_read_signal(struct rt2x00_dev *rt2x00dev,
struct rxdone_entry_desc *rxdesc)
{
@@ -531,6 +612,12 @@
rxdesc.flags |= RX_FLAG_HT;
/*
+ * Check if this is a beacon, and more frames have been
+ * buffered while we were in powersaving mode.
+ */
+ rt2x00lib_rxdone_check_ps(rt2x00dev, entry->skb, &rxdesc);
+
+ /*
* Update extra components
*/
rt2x00link_update_stats(rt2x00dev, entry->skb, &rxdesc);
@@ -1017,6 +1104,7 @@
}
INIT_WORK(&rt2x00dev->intf_work, rt2x00lib_intf_scheduled);
+ INIT_DELAYED_WORK(&rt2x00dev->autowakeup_work, rt2x00lib_autowakeup);
/*
* Let the driver probe the device to detect the capabilities.