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Date: Sat, 3 Jul 2010 00:02:59 -0700
From: Vasanthakumar Thiagarajan <vasanth@atheros.com>
To: Ben Greear <greearb@candelatech.com>
CC: "linux-wireless@vger.kernel.org" <linux-wireless@vger.kernel.org>
Subject: Re: ath9k doesn't clean up virtual wifis on rmmod, and crashes.
Message-ID: <20100703070259.GA15479@vasanth-laptop>
References: <4C2ED806.9000105@candelatech.com>
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On Sat, Jul 03, 2010 at 11:56:14AM +0530, Ben Greear wrote:
> It seems to me that in 2.6.34, there is no code to clean up
> virtual wiphys in ath9k on rmmod.  Also, ath9k mailing list
> is returning error about mis-configured DNS server.
> 
> This is with un-modified ath9k driver and is repeatable
> every time on my system (crash is often different, but
> it always crashes very quickly).
> 
> [root@atom ~]# echo add=5 > /debug/ath9k/phy1/wiphy
> -bash: /debug/ath9k/phy1/wiphy: No such file or directory
> [root@atom ~]# echo add=5 > /debug/ath9k/phy0/wiphy
> Jul  2 23:22:19 atom kernel: phy1: Selected rate control algorithm 'ath9k_rate_control'
> [root@atom ~]# Jul  2 23:22:19 atom kernel: ADDRCONF(NETDEV_UP): wlan1: link is not ready
> rmmod ath9k
> Jul  2 23:22:24 atom kernel: ath9k 0000:05:00.0: PCI INT A disabled
> Jul  2 23:22:24 atom kernel: ath9k: Driver unloaded
> [root@atom ~]# BUG: spinlock bad magic on CPU#1, iw/2877
>   lock: f8a476c0, .magic: 00000000, .owner: <none>/-1, .owner_cpu: 0
> Pid: 2877, comm: iw Not tainted 2.6.34 #7
> Call Trace:
>   [<c0730e34>] ? printk+0xf/0x13
>   [<c05710d6>] spin_bug+0x7b/0x86
>   [<c0440b76>] ? delayed_work_timer_fn+0x0/0x30
>   [<c0571171>] do_raw_spin_lock+0x1e/0x125
>   [<c042f91e>] ? scheduler_tick+0xd6/0x1c9
>   [<c0440b76>] ? delayed_work_timer_fn+0x0/0x30
>   [<c0732a6d>] _raw_spin_lock_irqsave+0x1b/0x20
>   [<c0440b59>] __queue_work+0x12/0x2f
>   [<c0440b76>] ? delayed_work_timer_fn+0x0/0x30
>   [<c0440ba4>] delayed_work_timer_fn+0x2e/0x30
> 
> I'm new to hacking on this driver..but would love to test
> patches, and if someone wants to suggest a good point in
> the code to remove the virtual phys, I'll make the attempt.

Can you please try this patch?


diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 3a14630..6218890 100644
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -516,6 +516,7 @@ void ath_deinit_leds(struct ath_softc *sc);
 #define SC_OP_TSF_RESET              BIT(11)
 #define SC_OP_BT_PRIORITY_DETECTED   BIT(12)
 #define SC_OP_BT_SCAN		     BIT(13)
+#define SC_OP_ANI_RUN		     BIT(14)
 
 /* Powersave flags */
 #define PS_WAIT_FOR_BEACON        BIT(0)
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 5af2596..41a317d 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -451,6 +451,10 @@ static void ath_start_ani(struct ath_common *common)
 {
 	struct ath_hw *ah = common->ah;
 	unsigned long timestamp = jiffies_to_msecs(jiffies);
+	struct ath_softc *sc = (struct ath_softc *) common->priv;
+
+	if (!(sc->sc_flags & SC_OP_ANI_RUN))
+		return;
 
 	common->ani.longcal_timer = timestamp;
 	common->ani.shortcal_timer = timestamp;
@@ -766,11 +770,13 @@ static void ath9k_bss_assoc_info(struct ath_softc *sc,
 		/* Reset rssi stats */
 		sc->sc_ah->stats.avgbrssi = ATH_RSSI_DUMMY_MARKER;
 
+		sc->sc_flags |= SC_OP_ANI_RUN;
 		ath_start_ani(common);
 	} else {
 		ath_print(common, ATH_DBG_CONFIG, "Bss Info DISASSOC\n");
 		common->curaid = 0;
 		/* Stop ANI */
+		sc->sc_flags &= ~SC_OP_ANI_RUN;
 		del_timer_sync(&common->ani.timer);
 	}
 }
@@ -1376,8 +1382,10 @@ static int ath9k_add_interface(struct ieee80211_hw *hw,
 
 	if (vif->type == NL80211_IFTYPE_AP    ||
 	    vif->type == NL80211_IFTYPE_ADHOC ||
-	    vif->type == NL80211_IFTYPE_MONITOR)
+	    vif->type == NL80211_IFTYPE_MONITOR) {
+		sc->sc_flags |= SC_OP_ANI_RUN;
 		ath_start_ani(common);
+	}
 
 out:
 	mutex_unlock(&sc->mutex);
@@ -1398,6 +1406,7 @@ static void ath9k_remove_interface(struct ieee80211_hw *hw,
 	mutex_lock(&sc->mutex);
 
 	/* Stop ANI */
+	sc->sc_flags &= ~SC_OP_ANI_RUN;
 	del_timer_sync(&common->ani.timer);
 
 	/* Reclaim beacon resources */
-- 


Vasanth