[rt2x00-users] [RFC] Add autowake support for USB hardware
Ivo van Doorn
ivdoorn at gmail.com
Tue Apr 12 03:04:14 EST 2011
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
Signed-off-by: Ivo van Doorn <IvDoorn at gmail.com>
---
Please review carefully, during my ping test I got 3% packet loss which is quite reasonable
in my testing environment. However I still got high ping times (64ms, instead of 4ms when
testing with PS disabled, or testing with an atheros card with PS enabled).
---
diff --git a/drivers/net/wireless/rt2x00/rt2500usb.c b/drivers/net/wireless/rt2x00/rt2500usb.c
index 6c9bba2..ffff199 100644
--- a/drivers/net/wireless/rt2x00/rt2500usb.c
+++ b/drivers/net/wireless/rt2x00/rt2500usb.c
@@ -1797,6 +1797,7 @@ static int rt2500usb_probe_hw(struct rt2x00_dev *rt2x00dev)
__set_bit(REQUIRE_COPY_IV, &rt2x00dev->cap_flags);
}
__set_bit(REQUIRE_SW_SEQNO, &rt2x00dev->cap_flags);
+ __set_bit(REQUIRE_PS_AUTOWAKE, &rt2x00dev->cap_flags);
/*
* Set the rssi offset.
diff --git a/drivers/net/wireless/rt2x00/rt2800usb.c b/drivers/net/wireless/rt2x00/rt2800usb.c
index bf07b1d..73dc4fd 100644
--- a/drivers/net/wireless/rt2x00/rt2800usb.c
+++ b/drivers/net/wireless/rt2x00/rt2800usb.c
@@ -633,6 +633,7 @@ static int rt2800usb_probe_hw(struct rt2x00_dev *rt2x00dev)
__set_bit(CAPABILITY_LINK_TUNING, &rt2x00dev->cap_flags);
__set_bit(REQUIRE_HT_TX_DESC, &rt2x00dev->cap_flags);
__set_bit(REQUIRE_TXSTATUS_FIFO, &rt2x00dev->cap_flags);
+ __set_bit(REQUIRE_PS_AUTOWAKE, &rt2x00dev->cap_flags);
setup_timer(&rt2x00dev->txstatus_timer,
rt2800usb_tx_sta_fifo_timeout,
diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 8f37121..df93a45 100644
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -662,6 +662,7 @@ enum rt2x00_state_flags {
* Driver configuration
*/
CONFIG_CHANNEL_HT40,
+ CONFIG_POWERSAVING,
};
/*
@@ -681,6 +682,7 @@ enum rt2x00_capability_flags {
REQUIRE_TASKLET_CONTEXT,
REQUIRE_SW_SEQNO,
REQUIRE_HT_TX_DESC,
+ REQUIRE_PS_AUTOWAKE,
/*
* Capabilities
@@ -874,6 +876,11 @@ struct rt2x00_dev {
u8 calibration[2];
/*
+ * Association id.
+ */
+ u16 aid;
+
+ /*
* Beacon interval.
*/
u16 beacon_int;
@@ -906,6 +913,11 @@ struct rt2x00_dev {
struct work_struct txdone_work;
/*
+ * Powersaving work
+ */
+ struct delayed_work autowakeup_work;
+
+ /*
* Data queue arrays for RX, TX, Beacon and ATIM.
*/
unsigned int data_queues;
diff --git a/drivers/net/wireless/rt2x00/rt2x00config.c b/drivers/net/wireless/rt2x00/rt2x00config.c
index e225a66..376964c 100644
--- a/drivers/net/wireless/rt2x00/rt2x00config.c
+++ b/drivers/net/wireless/rt2x00/rt2x00config.c
@@ -100,6 +100,9 @@ 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;
+
/* Update global beacon interval time, this is needed for PS support */
rt2x00dev->beacon_int = bss_conf->beacon_int;
@@ -192,6 +195,11 @@ void rt2x00lib_config(struct rt2x00_dev *rt2x00dev,
sizeof(libconf.channel));
}
+ if (test_bit(REQUIRE_PS_AUTOWAKE, &rt2x00dev->flags) &&
+ (ieee80211_flags & IEEE80211_CONF_CHANGE_PS) &&
+ !(conf->flags & IEEE80211_CONF_PS))
+ cancel_delayed_work_sync(&rt2x00dev->autowakeup_work);
+
/*
* Start configuration.
*/
@@ -204,6 +212,18 @@ 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->flags) &&
+ (ieee80211_flags & IEEE80211_CONF_CHANGE_PS) &&
+ (conf->flags & IEEE80211_CONF_PS))
+ queue_delayed_work(rt2x00dev->workqueue,
+ &rt2x00dev->autowakeup_work,
+ msecs_to_jiffies(rt2x00dev->beacon_int) - 1);
+
+ if (conf->flags & IEEE80211_CONF_PS)
+ test_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;
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 7776d9f..5242437 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -141,6 +141,16 @@ static void rt2x00lib_intf_scheduled(struct work_struct *work)
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 @@ void rt2x00lib_txdone_noinfo(struct queue_entry *entry, u32 status)
}
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) ||
+ test_bit(CONFIG_POWERSAVING, &rt2x00dev->flags)))
+ 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;
+
+ 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) {
+ 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 @@ void rt2x00lib_rxdone(struct queue_entry *entry)
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 @@ int rt2x00lib_probe_dev(struct rt2x00_dev *rt2x00dev)
}
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.
diff --git a/drivers/net/wireless/rt2x00/rt73usb.c b/drivers/net/wireless/rt2x00/rt73usb.c
index 4f807a6..96fbc4d 100644
--- a/drivers/net/wireless/rt2x00/rt73usb.c
+++ b/drivers/net/wireless/rt2x00/rt73usb.c
@@ -2209,6 +2209,7 @@ static int rt73usb_probe_hw(struct rt2x00_dev *rt2x00dev)
if (!modparam_nohwcrypt)
__set_bit(CAPABILITY_HW_CRYPTO, &rt2x00dev->cap_flags);
__set_bit(CAPABILITY_LINK_TUNING, &rt2x00dev->cap_flags);
+ __set_bit(REQUIRE_PS_AUTOWAKE, &rt2x00dev->cap_flags);
/*
* Set the rssi offset.
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