[PATCH 0/4] ath9k: Power save mode fixes

[PATCH 0/4] ath9k: Power save mode fixes

[Jouni Malinen]

This series addresses couple of issues in power save mode operations in
ath9k. The driver will now try to receive all buffered broadcast and
multicast frames after DTIM beacons. In addition, the transitions
between power save states are optimized in a way which should reduce
both CPU use and the amount of time spent in awake state. This change
seems to also improve the stability of the connection when using power
save mode.

There are still some remaining issues in the timeout=0 power save case
("iwconfig wlan0 power on"), but the patches here seem to make the
default mode (timeout=500, "iwconfig wlan0 power timeout 500ms") behave
much more nicely.

-- 
Jouni Malinen                                            PGP id EFC895FA

[PATCH 1/4] ath9k: Fix a check for multicast address for virtual wiphy

[Jouni Malinen]

The broadcast bit is in the first, not the last octet..

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>

---
 drivers/net/wireless/ath/ath9k/recv.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- wireless-testing.orig/drivers/net/wireless/ath/ath9k/recv.c	2009-05-14 21:04:12.000000000 +0300
+++ wireless-testing/drivers/net/wireless/ath/ath9k/recv.c	2009-05-14 21:12:18.000000000 +0300
@@ -637,7 +637,7 @@ int ath_rx_tasklet(struct ath_softc *sc,
 		}
 
 		/* Send the frame to mac80211 */
-		if (hdr->addr1[5] & 0x01) {
+		if (is_multicast_ether_addr(hdr->addr1)) {
 			int i;
 			/*
 			 * Deliver broadcast/multicast frames to all suitable

-- 

-- 
Jouni Malinen                                            PGP id EFC895FA

[PATCH 2/4] ath9k: Clean up RX processing a bit

[Jouni Malinen]

This makes use of the local fc variable in bit more places and uses a
common helper macro. The part of RX process that delivers skb's to
mac80211 is moved to a separate function in preparation for future
changes that will need to do this from two places. The modifications
here should not result in any functional changes.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>

---
 drivers/net/wireless/ath/ath9k/recv.c |   60 +++++++++++++++++++---------------
 1 file changed, 34 insertions(+), 26 deletions(-)

--- wireless-testing.orig/drivers/net/wireless/ath/ath9k/recv.c	2009-05-14 21:12:18.000000000 +0300
+++ wireless-testing/drivers/net/wireless/ath/ath9k/recv.c	2009-05-14 21:12:22.000000000 +0300
@@ -473,6 +473,37 @@ void ath_flushrecv(struct ath_softc *sc)
 	spin_unlock_bh(&sc->rx.rxflushlock);
 }
 
+static void ath_rx_send_to_mac80211(struct ath_softc *sc, struct sk_buff *skb,
+				    struct ieee80211_rx_status *rx_status)
+{
+	struct ieee80211_hdr *hdr;
+
+	hdr = (struct ieee80211_hdr *)skb->data;
+
+	/* Send the frame to mac80211 */
+	if (is_multicast_ether_addr(hdr->addr1)) {
+		int i;
+		/*
+		 * Deliver broadcast/multicast frames to all suitable
+		 * virtual wiphys.
+		 */
+		/* TODO: filter based on channel configuration */
+		for (i = 0; i < sc->num_sec_wiphy; i++) {
+			struct ath_wiphy *aphy = sc->sec_wiphy[i];
+			struct sk_buff *nskb;
+			if (aphy == NULL)
+				continue;
+			nskb = skb_copy(skb, GFP_ATOMIC);
+			if (nskb)
+				__ieee80211_rx(aphy->hw, nskb, rx_status);
+		}
+		__ieee80211_rx(sc->hw, skb, rx_status);
+	} else {
+		/* Deliver unicast frames based on receiver address */
+		__ieee80211_rx(ath_get_virt_hw(sc, hdr), skb, rx_status);
+	}
+}
+
 int ath_rx_tasklet(struct ath_softc *sc, int flush)
 {
 #define PA2DESC(_sc, _pa)                                               \
@@ -622,7 +653,7 @@ int ath_rx_tasklet(struct ath_softc *sc,
 
 		if (!(keyix == ATH9K_RXKEYIX_INVALID) && !decrypt_error) {
 			rx_status.flag |= RX_FLAG_DECRYPTED;
-		} else if ((le16_to_cpu(hdr->frame_control) & IEEE80211_FCTL_PROTECTED)
+		} else if (ieee80211_has_protected(fc)
 			   && !decrypt_error && skb->len >= hdrlen + 4) {
 			keyix = skb->data[hdrlen + 3] >> 6;
 
@@ -631,35 +662,12 @@ int ath_rx_tasklet(struct ath_softc *sc,
 		}
 		if (ah->sw_mgmt_crypto &&
 		    (rx_status.flag & RX_FLAG_DECRYPTED) &&
-		    ieee80211_is_mgmt(hdr->frame_control)) {
+		    ieee80211_is_mgmt(fc)) {
 			/* Use software decrypt for management frames. */
 			rx_status.flag &= ~RX_FLAG_DECRYPTED;
 		}
 
-		/* Send the frame to mac80211 */
-		if (is_multicast_ether_addr(hdr->addr1)) {
-			int i;
-			/*
-			 * Deliver broadcast/multicast frames to all suitable
-			 * virtual wiphys.
-			 */
-			/* TODO: filter based on channel configuration */
-			for (i = 0; i < sc->num_sec_wiphy; i++) {
-				struct ath_wiphy *aphy = sc->sec_wiphy[i];
-				struct sk_buff *nskb;
-				if (aphy == NULL)
-					continue;
-				nskb = skb_copy(skb, GFP_ATOMIC);
-				if (nskb)
-					__ieee80211_rx(aphy->hw, nskb,
-						       &rx_status);
-			}
-			__ieee80211_rx(sc->hw, skb, &rx_status);
-		} else {
-			/* Deliver unicast frames based on receiver address */
-			__ieee80211_rx(ath_get_virt_hw(sc, hdr), skb,
-				       &rx_status);
-		}
+		ath_rx_send_to_mac80211(sc, skb, &rx_status);
 
 		/* We will now give hardware our shiny new allocated skb */
 		bf->bf_mpdu = requeue_skb;

-- 

-- 
Jouni Malinen                                            PGP id EFC895FA

[PATCH 3/4] ath9k: Fix PS mode operation to receive buffered broadcast/multicast frames

[Jouni Malinen]

The previous implementation was moving back to NETWORK SLEEP state
immediately after receiving a Beacon frame. This means that we are
unlikely to receive all the buffered broadcast/multicast frames that
would be sent after DTIM Beacon frames. Fix this by parsing the Beacon
frame and remaining awake, if needed, to receive the buffered
broadcast/multicast frames. The last buffered frame will trigger the
move back into NETWORK SLEEP state.

If the last broadcast/multicast frame is not received properly (or if
the AP fails to send it), the next Beacon frame will work as a backup
trigger for returning into NETWORK SLEEP.

A new debug type, PS (debug=0x800 module parameter), is added to make
it easier to debug potential power save issues in the
future. Currently, this is only used for the Beacon frame and buffered
broadcast/multicast receiving.

Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>

---
 drivers/net/wireless/ath/ath9k/ath9k.h |    1 
 drivers/net/wireless/ath/ath9k/debug.h |    1 
 drivers/net/wireless/ath/ath9k/recv.c  |  119 +++++++++++++++++++++++++++++++--
 3 files changed, 114 insertions(+), 7 deletions(-)

--- wireless-testing.orig/drivers/net/wireless/ath/ath9k/ath9k.h	2009-05-14 21:04:12.000000000 +0300
+++ wireless-testing/drivers/net/wireless/ath/ath9k/ath9k.h	2009-05-14 21:12:24.000000000 +0300
@@ -519,6 +519,7 @@ struct ath_rfkill {
 #define SC_OP_LED_ON            BIT(13)
 #define SC_OP_SCANNING          BIT(14)
 #define SC_OP_TSF_RESET         BIT(15)
+#define SC_OP_WAIT_FOR_CAB      BIT(16)
 
 struct ath_bus_ops {
 	void		(*read_cachesize)(struct ath_softc *sc, int *csz);
--- wireless-testing.orig/drivers/net/wireless/ath/ath9k/recv.c	2009-05-14 21:12:22.000000000 +0300
+++ wireless-testing/drivers/net/wireless/ath/ath9k/recv.c	2009-05-14 21:12:24.000000000 +0300
@@ -473,6 +473,112 @@ void ath_flushrecv(struct ath_softc *sc)
 	spin_unlock_bh(&sc->rx.rxflushlock);
 }
 
+static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
+{
+	/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */
+	struct ieee80211_mgmt *mgmt;
+	u8 *pos, *end, id, elen;
+	struct ieee80211_tim_ie *tim;
+
+	mgmt = (struct ieee80211_mgmt *)skb->data;
+	pos = mgmt->u.beacon.variable;
+	end = skb->data + skb->len;
+
+	while (pos + 2 < end) {
+		id = *pos++;
+		elen = *pos++;
+		if (pos + elen > end)
+			break;
+
+		if (id == WLAN_EID_TIM) {
+			if (elen < sizeof(*tim))
+				break;
+			tim = (struct ieee80211_tim_ie *) pos;
+			if (tim->dtim_count != 0)
+				break;
+			return tim->bitmap_ctrl & 0x01;
+		}
+
+		pos += elen;
+	}
+
+	return false;
+}
+
+static void ath_rx_ps_back_to_sleep(struct ath_softc *sc)
+{
+	sc->sc_flags &= ~(SC_OP_WAIT_FOR_BEACON | SC_OP_WAIT_FOR_CAB);
+	if (sc->hw->conf.flags & IEEE80211_CONF_PS)
+		ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_NETWORK_SLEEP);
+}
+
+static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
+{
+	struct ieee80211_mgmt *mgmt;
+
+	if (skb->len < 24 + 8 + 2 + 2)
+		return;
+
+	mgmt = (struct ieee80211_mgmt *)skb->data;
+	if (memcmp(sc->curbssid, mgmt->bssid, ETH_ALEN) != 0)
+		return; /* not from our current AP */
+
+	if (!(sc->hw->conf.flags & IEEE80211_CONF_PS)) {
+		/* We are not in PS mode anymore; remain awake */
+		DPRINTF(sc, ATH_DBG_PS, "Not in PS mode anymore, remain "
+			"awake\n");
+		sc->sc_flags &= ~(SC_OP_WAIT_FOR_BEACON | SC_OP_WAIT_FOR_CAB);
+		return;
+	}
+
+	if (ath_beacon_dtim_pending_cab(skb)) {
+		/*
+		 * Remain awake waiting for buffered broadcast/multicast
+		 * frames.
+		 */
+		DPRINTF(sc, ATH_DBG_PS, "Received DTIM beacon indicating "
+			"buffered broadcast/multicast frame(s)\n");
+		sc->sc_flags |= SC_OP_WAIT_FOR_CAB;
+		return;
+	}
+
+	if (sc->sc_flags & SC_OP_WAIT_FOR_CAB) {
+		/*
+		 * This can happen if a broadcast frame is dropped or the AP
+		 * fails to send a frame indicating that all CAB frames have
+		 * been delivered.
+		 */
+		DPRINTF(sc, ATH_DBG_PS, "PS wait for CAB frames timed out\n");
+	}
+
+	/* No more broadcast/multicast frames to be received at this point. */
+	ath_rx_ps_back_to_sleep(sc);
+}
+
+static void ath_rx_ps(struct ath_softc *sc, struct sk_buff *skb)
+{
+	struct ieee80211_hdr *hdr;
+
+	hdr = (struct ieee80211_hdr *)skb->data;
+
+	/* Process Beacon and CAB receive in PS state */
+	if (ieee80211_is_beacon(hdr->frame_control))
+		ath_rx_ps_beacon(sc, skb);
+	else if ((sc->sc_flags & SC_OP_WAIT_FOR_CAB) &&
+		 (ieee80211_is_data(hdr->frame_control) ||
+		  ieee80211_is_action(hdr->frame_control)) &&
+		 is_multicast_ether_addr(hdr->addr1) &&
+		 !ieee80211_has_moredata(hdr->frame_control)) {
+		DPRINTF(sc, ATH_DBG_PS, "All PS CAB frames received, back to "
+			"sleep\n");
+		/*
+		 * No more broadcast/multicast frames to be received at this
+		 * point.
+		 */
+		ath_rx_ps_back_to_sleep(sc);
+	}
+}
+
 static void ath_rx_send_to_mac80211(struct ath_softc *sc, struct sk_buff *skb,
 				    struct ieee80211_rx_status *rx_status)
 {
@@ -667,8 +773,6 @@ int ath_rx_tasklet(struct ath_softc *sc,
 			rx_status.flag &= ~RX_FLAG_DECRYPTED;
 		}
 
-		ath_rx_send_to_mac80211(sc, skb, &rx_status);
-
 		/* We will now give hardware our shiny new allocated skb */
 		bf->bf_mpdu = requeue_skb;
 		bf->bf_buf_addr = dma_map_single(sc->dev, requeue_skb->data,
@@ -680,6 +784,7 @@ int ath_rx_tasklet(struct ath_softc *sc,
 			bf->bf_mpdu = NULL;
 			DPRINTF(sc, ATH_DBG_FATAL,
 				"dma_mapping_error() on RX\n");
+			ath_rx_send_to_mac80211(sc, skb, &rx_status);
 			break;
 		}
 		bf->bf_dmacontext = bf->bf_buf_addr;
@@ -695,11 +800,11 @@ int ath_rx_tasklet(struct ath_softc *sc,
 			sc->rx.rxotherant = 0;
 		}
 
-		if (ieee80211_is_beacon(fc) &&
-				(sc->sc_flags & SC_OP_WAIT_FOR_BEACON)) {
-			sc->sc_flags &= ~SC_OP_WAIT_FOR_BEACON;
-			ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_NETWORK_SLEEP);
-		}
+		if (unlikely(sc->sc_flags & SC_OP_WAIT_FOR_BEACON))
+			ath_rx_ps(sc, skb);
+
+		ath_rx_send_to_mac80211(sc, skb, &rx_status);
+
 requeue:
 		list_move_tail(&bf->list, &sc->rx.rxbuf);
 		ath_rx_buf_link(sc, bf);
--- wireless-testing.orig/drivers/net/wireless/ath/ath9k/debug.h	2009-05-14 21:04:11.000000000 +0300
+++ wireless-testing/drivers/net/wireless/ath/ath9k/debug.h	2009-05-14 21:12:24.000000000 +0300
@@ -29,6 +29,7 @@ enum ATH_DEBUG {
 	ATH_DBG_BEACON		= 0x00000100,
 	ATH_DBG_CONFIG		= 0x00000200,
 	ATH_DBG_FATAL		= 0x00000400,
+	ATH_DBG_PS		= 0x00000800,
 	ATH_DBG_ANY		= 0xffffffff
 };
 

-- 

-- 
Jouni Malinen                                            PGP id EFC895FA

[PATCH 4/4] ath9k: Move PS wakeup/restore calls from isr to tasklet

[Jouni Malinen]

From: Vasanthakumar Thiagarajan <vasanth@atheros.com>

We do not need to do this in ath_isr() and it looks like the modified
version ends up being more stable as far as being able receive beacon
frames is concerned. Furthermore, this reduces need to move between
AWAKE and NETWORK SLEEP states when processing some unrelated
interrupts.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>

---
 drivers/net/wireless/ath/ath9k/main.c |   23 +++++++++--------------
 drivers/net/wireless/ath/ath9k/recv.c |    2 --
 2 files changed, 9 insertions(+), 16 deletions(-)

--- wireless-testing.orig/drivers/net/wireless/ath/ath9k/main.c	2009-05-14 21:04:10.000000000 +0300
+++ wireless-testing/drivers/net/wireless/ath/ath9k/main.c	2009-05-14 21:13:14.000000000 +0300
@@ -455,8 +455,11 @@ static void ath9k_tasklet(unsigned long 
 	struct ath_softc *sc = (struct ath_softc *)data;
 	u32 status = sc->intrstatus;
 
+	ath9k_ps_wakeup(sc);
+
 	if (status & ATH9K_INT_FATAL) {
 		ath_reset(sc, false);
+		ath9k_ps_restore(sc);
 		return;
 	}
 
@@ -471,6 +474,7 @@ static void ath9k_tasklet(unsigned long 
 
 	/* re-enable hardware interrupt */
 	ath9k_hw_set_interrupts(sc->sc_ah, sc->imask);
+	ath9k_ps_restore(sc);
 }
 
 irqreturn_t ath_isr(int irq, void *dev)
@@ -498,14 +502,11 @@ irqreturn_t ath_isr(int irq, void *dev)
 	if (sc->sc_flags & SC_OP_INVALID)
 		return IRQ_NONE;
 
-	ath9k_ps_wakeup(sc);
 
 	/* shared irq, not for us */
 
-	if (!ath9k_hw_intrpend(ah)) {
-		ath9k_ps_restore(sc);
+	if (!ath9k_hw_intrpend(ah))
 		return IRQ_NONE;
-	}
 
 	/*
 	 * Figure out the reason(s) for the interrupt.  Note
@@ -520,10 +521,8 @@ irqreturn_t ath_isr(int irq, void *dev)
 	 * If there are no status bits set, then this interrupt was not
 	 * for me (should have been caught above).
 	 */
-	if (!status) {
-		ath9k_ps_restore(sc);
+	if (!status)
 		return IRQ_NONE;
-	}
 
 	/* Cache the status */
 	sc->intrstatus = status;
@@ -560,20 +559,16 @@ irqreturn_t ath_isr(int irq, void *dev)
 		ath9k_hw_set_interrupts(ah, sc->imask);
 	}
 
-	if (status & ATH9K_INT_TIM_TIMER) {
-		if (!(ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP)) {
+	if (!(ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP))
+		if (status & ATH9K_INT_TIM_TIMER) {
 			/* Clear RxAbort bit so that we can
 			 * receive frames */
-			ath9k_hw_setpower(ah, ATH9K_PM_AWAKE);
-			ath9k_hw_setrxabort(ah, 0);
-			sched = true;
+			ath9k_hw_setrxabort(sc->sc_ah, 0);
 			sc->sc_flags |= SC_OP_WAIT_FOR_BEACON;
 		}
-	}
 
 chip_reset:
 
-	ath9k_ps_restore(sc);
 	ath_debug_stat_interrupt(sc, status);
 
 	if (sched) {
--- wireless-testing.orig/drivers/net/wireless/ath/ath9k/recv.c	2009-05-14 21:12:24.000000000 +0300
+++ wireless-testing/drivers/net/wireless/ath/ath9k/recv.c	2009-05-14 21:13:14.000000000 +0300
@@ -508,8 +508,6 @@ static bool ath_beacon_dtim_pending_cab(
 static void ath_rx_ps_back_to_sleep(struct ath_softc *sc)
 {
 	sc->sc_flags &= ~(SC_OP_WAIT_FOR_BEACON | SC_OP_WAIT_FOR_CAB);
-	if (sc->hw->conf.flags & IEEE80211_CONF_PS)
-		ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_NETWORK_SLEEP);
 }
 
 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)

-- 

-- 
Jouni Malinen                                            PGP id EFC895FA

Re: [PATCH 4/4] ath9k: Move PS wakeup/restore calls from isr to tasklet

[Luis R. Rodriguez]

On Thu, May 14, 2009 at 09:28:49PM +0300, Jouni Malinen wrote:
> From: Vasanthakumar Thiagarajan <vasanth@atheros.com>
> 
> We do not need to do this in ath_isr() and it looks like the modified
> version ends up being more stable as far as being able receive beacon
> frames is concerned. Furthermore, this reduces need to move between
> AWAKE and NETWORK SLEEP states when processing some unrelated
> interrupts.
> 
> Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
> Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>

John, this one is misisng one line, please apply this one instead:

From: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Subject: [PATCH] ath9k: Move PS wakeup/restore calls from isr to tasklet

We do not need to do this in ath_isr() and it looks like the modified
version ends up being more stable as far as being able receive beacon
frames is concerned. Furthermore, this reduces need to move between
AWAKE and NETWORK SLEEP states when processing some unrelated
interrupts.

Signed-off-by: Vasanthakumar Thiagarajan <vasanth@atheros.com>
Signed-off-by: Jouni Malinen <jouni.malinen@atheros.com>
---
 drivers/net/wireless/ath/ath9k/main.c |   22 +++++++++-------------
 drivers/net/wireless/ath/ath9k/recv.c |    2 --
 2 files changed, 9 insertions(+), 15 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index bbbfdcd..df9b7c1 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -455,8 +455,11 @@ static void ath9k_tasklet(unsigned long data)
 	struct ath_softc *sc = (struct ath_softc *)data;
 	u32 status = sc->intrstatus;
 
+	ath9k_ps_wakeup(sc);
+
 	if (status & ATH9K_INT_FATAL) {
 		ath_reset(sc, false);
+		ath9k_ps_restore(sc);
 		return;
 	}
 
@@ -471,6 +474,7 @@ static void ath9k_tasklet(unsigned long data)
 
 	/* re-enable hardware interrupt */
 	ath9k_hw_set_interrupts(sc->sc_ah, sc->imask);
+	ath9k_ps_restore(sc);
 }
 
 irqreturn_t ath_isr(int irq, void *dev)
@@ -498,14 +502,11 @@ irqreturn_t ath_isr(int irq, void *dev)
 	if (sc->sc_flags & SC_OP_INVALID)
 		return IRQ_NONE;
 
-	ath9k_ps_wakeup(sc);
 
 	/* shared irq, not for us */
 
-	if (!ath9k_hw_intrpend(ah)) {
-		ath9k_ps_restore(sc);
+	if (!ath9k_hw_intrpend(ah))
 		return IRQ_NONE;
-	}
 
 	/*
 	 * Figure out the reason(s) for the interrupt.  Note
@@ -520,10 +521,8 @@ irqreturn_t ath_isr(int irq, void *dev)
 	 * If there are no status bits set, then this interrupt was not
 	 * for me (should have been caught above).
 	 */
-	if (!status) {
-		ath9k_ps_restore(sc);
+	if (!status)
 		return IRQ_NONE;
-	}
 
 	/* Cache the status */
 	sc->intrstatus = status;
@@ -560,20 +559,17 @@ irqreturn_t ath_isr(int irq, void *dev)
 		ath9k_hw_set_interrupts(ah, sc->imask);
 	}
 
-	if (status & ATH9K_INT_TIM_TIMER) {
-		if (!(ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP)) {
+	if (!(ah->caps.hw_caps & ATH9K_HW_CAP_AUTOSLEEP))
+		if (status & ATH9K_INT_TIM_TIMER) {
 			/* Clear RxAbort bit so that we can
 			 * receive frames */
 			ath9k_hw_setpower(ah, ATH9K_PM_AWAKE);
-			ath9k_hw_setrxabort(ah, 0);
-			sched = true;
+			ath9k_hw_setrxabort(sc->sc_ah, 0);
 			sc->sc_flags |= SC_OP_WAIT_FOR_BEACON;
 		}
-	}
 
 chip_reset:
 
-	ath9k_ps_restore(sc);
 	ath_debug_stat_interrupt(sc, status);
 
 	if (sched) {
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 72e9283..5567517 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -508,8 +508,6 @@ static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
 static void ath_rx_ps_back_to_sleep(struct ath_softc *sc)
 {
 	sc->sc_flags &= ~(SC_OP_WAIT_FOR_BEACON | SC_OP_WAIT_FOR_CAB);
-	if (sc->hw->conf.flags & IEEE80211_CONF_PS)
-		ath9k_hw_setpower(sc->sc_ah, ATH9K_PM_NETWORK_SLEEP);
 }
 
 static void ath_rx_ps_beacon(struct ath_softc *sc, struct sk_buff *skb)
-- 
1.6.2.2.446.gfbdc0