[RFC,3/3] ath9k: implement the sw scan wait constraints

Commit Message

Luis Rodriguez Aug. 28, 2010, 7:13 a.m. UTC

None

Patch

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index f0197a6..89bbcd0 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -588,6 +588,7 @@  struct ath_softc {
 	int led_off_cnt;
 
 	int beacon_interval;
+	u32 scan_wait_counter;
 
 #ifdef CONFIG_ATH9K_DEBUGFS
 	struct ath9k_debug debug;
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 1165f90..181edea 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -2043,6 +2043,74 @@  static void ath9k_sw_scan_start(struct ieee80211_hw *hw)
 	mutex_unlock(&sc->mutex);
 }
 
+static void ath9k_ps_flags_dbg(struct ath_softc *sc)
+{
+#define ATH9K_WAIT_DBG(_reason) do { \
+	if (sc->ps_flags & _reason) \
+		ath_print(common, ATH_DBG_PS, \
+			  "  %s\n", #_reason); \
+	} while (0)
+
+	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+
+	ath_print(common, ATH_DBG_PS, "PS flags:\n");
+
+	ATH9K_WAIT_DBG(PS_WAIT_FOR_BEACON);
+	ATH9K_WAIT_DBG(PS_WAIT_FOR_CAB);
+	ATH9K_WAIT_DBG(PS_WAIT_FOR_PSPOLL_DATA);
+	ATH9K_WAIT_DBG(PS_WAIT_FOR_TX_ACK);
+	ATH9K_WAIT_DBG(PS_BEACON_SYNC);
+	ATH9K_WAIT_DBG(PS_NULLFUNC_COMPLETED);
+	ATH9K_WAIT_DBG(PS_ENABLED);
+
+#undef ATH9K_WAIT_DBG
+}
+
+/*
+ * We expect to be disassociated if the counter gets too high.
+ */
+static int ath9k_sw_scan_wait_constraints(struct ieee80211_hw *hw)
+{
+	struct ath_wiphy *aphy = hw->priv;
+	struct ath_softc *sc = aphy->sc;
+	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+	int r = 0;
+	u32 wait_for;
+
+	mutex_lock(&sc->mutex);
+
+	wait_for = PS_WAIT_FOR_BEACON |
+		   PS_BEACON_SYNC |
+		   PS_WAIT_FOR_CAB |
+		   PS_WAIT_FOR_PSPOLL_DATA |
+		   PS_WAIT_FOR_TX_ACK |
+		   PS_NULLFUNC_COMPLETED;
+
+	if (sc->ps_flags & wait_for) {
+		sc->scan_wait_counter++;
+		ath_print(common, ATH_DBG_PS,
+			  "Holding on channel change due to a "
+			  "wait constraint, count: %d, ps_flags: 0x%04x\n",
+			  sc->scan_wait_counter,
+			  sc->ps_flags);
+		ath9k_ps_flags_dbg(sc);
+		if (sc->ps_flags & PS_NULLFUNC_COMPLETED)
+			r = -EAGAIN;
+		else
+			r = -EBUSY;
+		goto out;
+	}
+
+	sc->scan_wait_counter = 0;
+	ath_print(common, ATH_DBG_PS,
+		  "No scan wait contraints found, ps_flags: 0x%04x\n",
+		   sc->ps_flags);
+out:
+	mutex_unlock(&sc->mutex);
+
+	return r;
+}
+
 /*
  * XXX: this requires a revisit after the driver
  * scan_complete gets moved to another place/removed in mac80211.
@@ -2089,6 +2157,7 @@  struct ieee80211_ops ath9k_ops = {
 	.ampdu_action       = ath9k_ampdu_action,
 	.get_survey	    = ath9k_get_survey,
 	.sw_scan_start      = ath9k_sw_scan_start,
+	.sw_scan_wait_constraints = ath9k_sw_scan_wait_constraints,
 	.sw_scan_complete   = ath9k_sw_scan_complete,
 	.rfkill_poll        = ath9k_rfkill_poll_state,
 	.set_coverage_class = ath9k_set_coverage_class,