linux-next-cherry-picks/0027-ath9k-Fix-work-handling.patch

From af68abadac378f7a4a44fe766383e7b88c7f9c3b Mon Sep 17 00:00:00 2001
From: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Date: Mon, 4 Jun 2012 20:23:43 +0530
Subject: [PATCH 27/57] ath9k: Fix work handling

* Currently, there is no synchronization between the reset
  work and the tx-poll work. Fix this and make sure that we
  bail out properly if a reset work is in progress.

* Cleanup the PLL WAR and enable it for AR9340 too and
  use a helper for restarting work/timers after a reset.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
---
 drivers/net/wireless/ath/ath9k/ath9k.h |    1 +
 drivers/net/wireless/ath/ath9k/link.c  |   33 ++++++++++++++++++--------------
 drivers/net/wireless/ath/ath9k/main.c  |   22 ++++++++++++++++-----
 3 files changed, 37 insertions(+), 19 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -431,6 +431,7 @@ void ath9k_set_beaconing_status(struct a
 #define ATH_RESTART_CALINTERVAL   1200000 /* 20 minutes */
 
 #define ATH_PAPRD_TIMEOUT	100 /* msecs */
+#define ATH_PLL_WORK_INTERVAL   100
 
 void ath_tx_complete_poll_work(struct work_struct *work);
 void ath_reset_work(struct work_struct *work);
--- a/drivers/net/wireless/ath/ath9k/link.c
+++ b/drivers/net/wireless/ath/ath9k/link.c
@@ -52,6 +52,7 @@ void ath_tx_complete_poll_work(struct wo
 			"tx hung, resetting the chip\n");
 		RESET_STAT_INC(sc, RESET_TYPE_TX_HANG);
 		ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
+		return;
 	}
 
 	ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work,
@@ -107,9 +108,9 @@ out:
 }
 
 /*
- * PLL-WAR for AR9485.
+ * PLL-WAR for AR9485/AR9340
  */
-static void ath_hw_pll_rx_hang_check(struct ath_softc *sc, u32 pll_sqsum)
+static bool ath_hw_pll_rx_hang_check(struct ath_softc *sc, u32 pll_sqsum)
 {
 	static int count;
 	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
@@ -117,29 +118,33 @@ static void ath_hw_pll_rx_hang_check(str
 	if (pll_sqsum >= 0x40000) {
 		count++;
 		if (count == 3) {
-			/* Rx is hung for more than 500ms. Reset it */
-			ath_dbg(common, RESET, "Possible RX hang, resetting\n");
+			ath_dbg(common, RESET, "PLL WAR, resetting the chip\n");
 			RESET_STAT_INC(sc, RESET_TYPE_PLL_HANG);
 			ieee80211_queue_work(sc->hw, &sc->hw_reset_work);
 			count = 0;
+			return true;
 		}
-	} else
+	} else {
 		count = 0;
+	}
+
+	return false;
 }
 
 void ath_hw_pll_work(struct work_struct *work)
 {
+	u32 pll_sqsum;
 	struct ath_softc *sc = container_of(work, struct ath_softc,
 					    hw_pll_work.work);
-	u32 pll_sqsum;
 
-	if (AR_SREV_9485(sc->sc_ah)) {
-		ath9k_ps_wakeup(sc);
-		pll_sqsum = ar9003_get_pll_sqsum_dvc(sc->sc_ah);
-		ath9k_ps_restore(sc);
-		ath_hw_pll_rx_hang_check(sc, pll_sqsum);
-		ieee80211_queue_delayed_work(sc->hw, &sc->hw_pll_work, HZ/5);
-	}
+	ath9k_ps_wakeup(sc);
+	pll_sqsum = ar9003_get_pll_sqsum_dvc(sc->sc_ah);
+	ath9k_ps_restore(sc);
+	if (ath_hw_pll_rx_hang_check(sc, pll_sqsum))
+		return;
+
+	ieee80211_queue_delayed_work(sc->hw, &sc->hw_pll_work,
+				     msecs_to_jiffies(ATH_PLL_WORK_INTERVAL));
 }
 
 /*
@@ -293,7 +298,7 @@ void ath_paprd_calibrate(struct work_str
 		if (ar9003_paprd_create_curve(ah, caldata, chain)) {
 			ath_dbg(common, CALIBRATE,
 				"PAPRD create curve failed on chain %d\n",
-								   chain);
+				chain);
 			break;
 		}
 
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -158,6 +158,22 @@ static void ath_cancel_work(struct ath_s
 	cancel_work_sync(&sc->hw_reset_work);
 }
 
+static void ath_restart_work(struct ath_softc *sc)
+{
+	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
+
+	ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work, 0);
+
+	if (AR_SREV_9485(sc->sc_ah) || AR_SREV_9340(sc->sc_ah))
+		ieee80211_queue_delayed_work(sc->hw, &sc->hw_pll_work,
+				     msecs_to_jiffies(ATH_PLL_WORK_INTERVAL));
+
+	ath_start_rx_poll(sc, 3);
+
+	if (!common->disable_ani)
+		ath_start_ani(common);
+}
+
 static bool ath_prepare_reset(struct ath_softc *sc, bool retry_tx, bool flush)
 {
 	struct ath_hw *ah = sc->sc_ah;
@@ -209,11 +225,7 @@ static bool ath_complete_reset(struct at
 		if (sc->sc_flags & SC_OP_BEACONS)
 			ath_set_beacon(sc);
 
-		ieee80211_queue_delayed_work(sc->hw, &sc->tx_complete_work, 0);
-		ieee80211_queue_delayed_work(sc->hw, &sc->hw_pll_work, HZ/2);
-		ath_start_rx_poll(sc, 3);
-		if (!common->disable_ani)
-			ath_start_ani(common);
+		ath_restart_work(sc);
 	}
 
 	if ((ah->caps.hw_caps & ATH9K_HW_CAP_ANT_DIV_COMB) && sc->ant_rx != 3) {