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Date:      Mon, 28 Nov 2016 17:54:29 +0000 (UTC)
From:      Adrian Chadd <adrian@FreeBSD.org>
To:        src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org
Subject:   svn commit: r309256 - head/sys/dev/ath
Message-ID:  <201611281754.uASHsTQe093467@repo.freebsd.org>
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Author: adrian
Date: Mon Nov 28 17:54:29 2016
New Revision: 309256
URL: https://svnweb.freebsd.org/changeset/base/309256

Log:
  [ath] force wake the hardware if we see a missed beacon.
  
  This adds a workaround to incorrectly behaving APs (ie, FreeBSD APs) which
  don't beacon out exactly when they should (at TBTT multiples of beacon
  intervals.)
  
  It forces the hardware awake (but leaves it in network-sleep so self
  generated frames still state that the hardware is asleep!) and will
  remain awake until the next sleep transition driven by net80211.
  
  That way if the beacons are just at the wrong interval, we get a much
  better chance of hearing more consecutive beacons before we go to sleep,
  thus not constantly disconnecting.
  
  Tested:
  
  * AR9485, STA mode, against a misbehaving FreeBSD AP.

Modified:
  head/sys/dev/ath/if_ath.c
  head/sys/dev/ath/if_ath_misc.h

Modified: head/sys/dev/ath/if_ath.c
==============================================================================
--- head/sys/dev/ath/if_ath.c	Mon Nov 28 17:24:24 2016	(r309255)
+++ head/sys/dev/ath/if_ath.c	Mon Nov 28 17:54:29 2016	(r309256)
@@ -285,22 +285,40 @@ ath_legacy_attach_comp_func(struct ath_s
  * the hardware is being programmed elsewhere, it will
  * simply store it away and update it when all current
  * uses of the hardware are completed.
+ *
+ * If the chip is going into network sleep or power off, then
+ * we will wait until all uses of the chip are done before
+ * going into network sleep or power off.
+ *
+ * If the chip is being programmed full-awake, then immediately
+ * program it full-awake so we can actually stay awake rather than
+ * the chip potentially going to sleep underneath us.
  */
 void
-_ath_power_setpower(struct ath_softc *sc, int power_state, const char *file, int line)
+_ath_power_setpower(struct ath_softc *sc, int power_state, int selfgen,
+    const char *file, int line)
 {
 	ATH_LOCK_ASSERT(sc);
 
-	sc->sc_target_powerstate = power_state;
-
-	DPRINTF(sc, ATH_DEBUG_PWRSAVE, "%s: (%s:%d) state=%d, refcnt=%d\n",
+	DPRINTF(sc, ATH_DEBUG_PWRSAVE, "%s: (%s:%d) state=%d, refcnt=%d, target=%d, cur=%d\n",
 	    __func__,
 	    file,
 	    line,
 	    power_state,
-	    sc->sc_powersave_refcnt);
+	    sc->sc_powersave_refcnt,
+	    sc->sc_target_powerstate,
+	    sc->sc_cur_powerstate);
 
-	if (sc->sc_powersave_refcnt == 0 &&
+	sc->sc_target_powerstate = power_state;
+
+	/*
+	 * Don't program the chip into network sleep if the chip
+	 * is being programmed elsewhere.
+	 *
+	 * However, if the chip is being programmed /awake/, force
+	 * the chip awake so we stay awake.
+	 */
+	if ((sc->sc_powersave_refcnt == 0 || power_state == HAL_PM_AWAKE) &&
 	    power_state != sc->sc_cur_powerstate) {
 		sc->sc_cur_powerstate = power_state;
 		ath_hal_setpower(sc->sc_ah, power_state);
@@ -313,7 +331,8 @@ _ath_power_setpower(struct ath_softc *sc
 		 * we let the above call leave the self-gen
 		 * state as "sleep".
 		 */
-		if (sc->sc_cur_powerstate == HAL_PM_AWAKE &&
+		if (selfgen &&
+		    sc->sc_cur_powerstate == HAL_PM_AWAKE &&
 		    sc->sc_target_selfgen_state != HAL_PM_AWAKE) {
 			ath_hal_setselfgenpower(sc->sc_ah,
 			    sc->sc_target_selfgen_state);
@@ -379,10 +398,13 @@ _ath_power_set_power_state(struct ath_so
 
 	sc->sc_powersave_refcnt++;
 
+	/*
+	 * Only do the power state change if we're not programming
+	 * it elsewhere.
+	 */
 	if (power_state != sc->sc_cur_powerstate) {
 		ath_hal_setpower(sc->sc_ah, power_state);
 		sc->sc_cur_powerstate = power_state;
-
 		/*
 		 * Adjust the self-gen powerstate if appropriate.
 		 */
@@ -391,7 +413,6 @@ _ath_power_set_power_state(struct ath_so
 			ath_hal_setselfgenpower(sc->sc_ah,
 			    sc->sc_target_selfgen_state);
 		}
-
 	}
 }
 
@@ -1317,7 +1338,7 @@ ath_attach(u_int16_t devid, struct ath_s
 	 * Put it to sleep for now.
 	 */
 	ATH_LOCK(sc);
-	ath_power_setpower(sc, HAL_PM_FULL_SLEEP);
+	ath_power_setpower(sc, HAL_PM_FULL_SLEEP, 1);
 	ATH_UNLOCK(sc);
 
 	return 0;
@@ -1359,7 +1380,7 @@ ath_detach(struct ath_softc *sc)
 	 */
 	ATH_LOCK(sc);
 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
-	ath_power_setpower(sc, HAL_PM_AWAKE);
+	ath_power_setpower(sc, HAL_PM_AWAKE, 1);
 
 	/*
 	 * Stop things cleanly.
@@ -1942,7 +1963,7 @@ ath_resume(struct ath_softc *sc)
 	ATH_LOCK(sc);
 	ath_power_setselfgen(sc, HAL_PM_AWAKE);
 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
-	ath_power_setpower(sc, HAL_PM_AWAKE);
+	ath_power_setpower(sc, HAL_PM_AWAKE, 1);
 	ATH_UNLOCK(sc);
 
 	ath_hal_reset(ah, sc->sc_opmode,
@@ -2269,8 +2290,13 @@ ath_intr(void *arg)
 			sc->sc_stats.ast_rxorn++;
 		}
 		if (status & HAL_INT_TSFOOR) {
+			/* out of range beacon - wake the chip up,
+			 * but don't modify self-gen frame config */
 			device_printf(sc->sc_dev, "%s: TSFOOR\n", __func__);
 			sc->sc_syncbeacon = 1;
+			ATH_LOCK(sc);
+			ath_power_setpower(sc, HAL_PM_AWAKE, 0);
+			ATH_UNLOCK(sc);
 		}
 		if (status & HAL_INT_MCI) {
 			ath_btcoex_mci_intr(sc);
@@ -2360,12 +2386,22 @@ ath_bmiss_vap(struct ieee80211vap *vap)
 	}
 
 	/*
-	 * There's no need to keep the hardware awake during the call
-	 * to av_bmiss().
+	 * Keep the hardware awake if it's asleep (and leave self-gen
+	 * frame config alone) until the next beacon, so we can resync
+	 * against the next beacon.
+	 *
+	 * This handles three common beacon miss cases in STA powersave mode -
+	 * (a) the beacon TBTT isnt a multiple of bintval;
+	 * (b) the beacon was missed; and
+	 * (c) the beacons are being delayed because the AP is busy and
+	 *     isn't reliably able to meet its TBTT.
 	 */
 	ATH_LOCK(sc);
+	ath_power_setpower(sc, HAL_PM_AWAKE, 0);
 	ath_power_restore_power_state(sc);
 	ATH_UNLOCK(sc);
+	DPRINTF(sc, ATH_DEBUG_BEACON,
+	    "%s: forced awake; force syncbeacon=1\n", __func__);
 
 	/*
 	 * Attempt to force a beacon resync.
@@ -2462,7 +2498,7 @@ ath_init(struct ath_softc *sc)
 	 */
 	ath_power_setselfgen(sc, HAL_PM_AWAKE);
 	ath_power_set_power_state(sc, HAL_PM_AWAKE);
-	ath_power_setpower(sc, HAL_PM_AWAKE);
+	ath_power_setpower(sc, HAL_PM_AWAKE, 1);
 
 	/*
 	 * Stop anything previously setup.  This is safe
@@ -5563,7 +5599,7 @@ ath_newstate(struct ieee80211vap *vap, e
 		/* Ensure we stay awake during scan */
 		ATH_LOCK(sc);
 		ath_power_setselfgen(sc, HAL_PM_AWAKE);
-		ath_power_setpower(sc, HAL_PM_AWAKE);
+		ath_power_setpower(sc, HAL_PM_AWAKE, 1);
 		ATH_UNLOCK(sc);
 
 		ath_hal_intrset(ah,
@@ -5739,7 +5775,7 @@ ath_newstate(struct ieee80211vap *vap, e
 		 */
 		ATH_LOCK(sc);
 		ath_power_setselfgen(sc, HAL_PM_AWAKE);
-		ath_power_setpower(sc, HAL_PM_AWAKE);
+		ath_power_setpower(sc, HAL_PM_AWAKE, 1);
 
 		/*
 		 * Finally, start any timers and the task q thread
@@ -5795,7 +5831,7 @@ ath_newstate(struct ieee80211vap *vap, e
 			 * our beacon timer config may be wrong.
 			 */
 			if (sc->sc_syncbeacon == 0) {
-				ath_power_setpower(sc, HAL_PM_NETWORK_SLEEP);
+				ath_power_setpower(sc, HAL_PM_NETWORK_SLEEP, 1);
 			}
 			ATH_UNLOCK(sc);
 		}
@@ -6177,7 +6213,7 @@ ath_parent(struct ieee80211com *ic)
 	} else {
 		ath_stop(sc);
 		if (!sc->sc_invalid)
-			ath_power_setpower(sc, HAL_PM_FULL_SLEEP);
+			ath_power_setpower(sc, HAL_PM_FULL_SLEEP, 1);
 	}
 	ATH_UNLOCK(sc);
 

Modified: head/sys/dev/ath/if_ath_misc.h
==============================================================================
--- head/sys/dev/ath/if_ath_misc.h	Mon Nov 28 17:24:24 2016	(r309255)
+++ head/sys/dev/ath/if_ath_misc.h	Mon Nov 28 17:54:29 2016	(r309256)
@@ -109,15 +109,23 @@ extern void ath_tx_dump(struct ath_softc
 /*
  * Power state tracking.
  */
-extern	void _ath_power_setpower(struct ath_softc *sc, int power_state, const char *file, int line);
-extern	void _ath_power_set_selfgen(struct ath_softc *sc, int power_state, const char *file, int line);
-extern	void _ath_power_set_power_state(struct ath_softc *sc, int power_state, const char *file, int line);
-extern	void _ath_power_restore_power_state(struct ath_softc *sc, const char *file, int line);
-
-#define	ath_power_setpower(sc, ps) _ath_power_setpower(sc, ps, __FILE__, __LINE__)
-#define	ath_power_setselfgen(sc, ps) _ath_power_set_selfgen(sc, ps, __FILE__, __LINE__)
-#define	ath_power_set_power_state(sc, ps) _ath_power_set_power_state(sc, ps, __FILE__, __LINE__)
-#define	ath_power_restore_power_state(sc) _ath_power_restore_power_state(sc, __FILE__, __LINE__)
+extern	void _ath_power_setpower(struct ath_softc *sc, int power_state,
+	    int selfgen, const char *file, int line);
+extern	void _ath_power_set_selfgen(struct ath_softc *sc,
+	    int power_state, const char *file, int line);
+extern	void _ath_power_set_power_state(struct ath_softc *sc,
+	    int power_state, const char *file, int line);
+extern	void _ath_power_restore_power_state(struct ath_softc *sc,
+	    const char *file, int line);
+
+#define	ath_power_setpower(sc, ps, sg) _ath_power_setpower(sc, ps, sg, \
+	    __FILE__, __LINE__)
+#define	ath_power_setselfgen(sc, ps) _ath_power_set_selfgen(sc, ps, \
+	    __FILE__, __LINE__)
+#define	ath_power_set_power_state(sc, ps) \
+	    _ath_power_set_power_state(sc, ps, __FILE__, __LINE__)
+#define	ath_power_restore_power_state(sc) \
+	    _ath_power_restore_power_state(sc, __FILE__, __LINE__)
 
 /*
  * Kick the frame TX task.

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