---

yaml
---
r: 291425
b: refs/heads/master
c: 290d608
h: refs/heads/master
i:
  291423: 19cd34d
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e9219779f943dfa1010ccbb63de14d49a47c43ee
+refs/heads/master: 290d60891eb659e52204ec209e08cc0cabc5b99f

trunk/drivers/net/wireless/rt2x00/rt2800.h

@@ -2474,6 +2474,12 @@ struct mac_iveiv_entry {
  */
 #define EIRP_MAX_TX_POWER_LIMIT	0x50
 
+/*
+ * Number of TBTT intervals after which we have to adjust
+ * the hw beacon timer.
+ */
+#define BCN_TBTT_OFFSET 64
+
 /*
  * RT2800 driver data structure
  */
@@ -2484,6 +2490,7 @@ struct rt2800_drv_data {
 	u8 bbp26;
 	u8 txmixer_gain_24g;
 	u8 txmixer_gain_5g;
+	unsigned int tbtt_tick;
 };
 
 #endif /* RT2800_H */

trunk/drivers/net/wireless/rt2x00/rt2800pci.c

@@ -809,7 +809,33 @@ static void rt2800pci_pretbtt_tasklet(unsigned long data)
 static void rt2800pci_tbtt_tasklet(unsigned long data)
 {
 	struct rt2x00_dev *rt2x00dev = (struct rt2x00_dev *)data;
+	struct rt2800_drv_data *drv_data = rt2x00dev->drv_data;
+	u32 reg;
+
 	rt2x00lib_beacondone(rt2x00dev);
+
+	if (rt2x00dev->intf_ap_count) {
+		/*
+		 * The rt2800pci hardware tbtt timer is off by 1us per tbtt
+		 * causing beacon skew and as a result causing problems with
+		 * some powersaving clients over time. Shorten the beacon
+		 * interval every 64 beacons by 64us to mitigate this effect.
+		 */
+		if (drv_data->tbtt_tick == (BCN_TBTT_OFFSET - 2)) {
+			rt2x00pci_register_read(rt2x00dev, BCN_TIME_CFG, &reg);
+			rt2x00_set_field32(&reg, BCN_TIME_CFG_BEACON_INTERVAL,
+					   (rt2x00dev->beacon_int * 16) - 1);
+			rt2x00pci_register_write(rt2x00dev, BCN_TIME_CFG, reg);
+		} else if (drv_data->tbtt_tick == (BCN_TBTT_OFFSET - 1)) {
+			rt2x00pci_register_read(rt2x00dev, BCN_TIME_CFG, &reg);
+			rt2x00_set_field32(&reg, BCN_TIME_CFG_BEACON_INTERVAL,
+					   (rt2x00dev->beacon_int * 16));
+			rt2x00pci_register_write(rt2x00dev, BCN_TIME_CFG, reg);
+		}
+		drv_data->tbtt_tick++;
+		drv_data->tbtt_tick %= BCN_TBTT_OFFSET;
+	}
+
 	if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
 		rt2800pci_enable_interrupt(rt2x00dev, INT_MASK_CSR_TBTT);
 }