From e53a3539e2582f2755b07494e82abfa7358262f6 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Wed, 20 Oct 2010 14:01:53 +0000
Subject: [PATCH] ath9k: fix a crash that happens when survey stats are
 accessed before the interface is brought up for the first time

SVN-Revision: 23549
---
 .../patches/540-ath9k_fix_survey_crash.patch         | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 package/mac80211/patches/540-ath9k_fix_survey_crash.patch

diff --git a/package/mac80211/patches/540-ath9k_fix_survey_crash.patch b/package/mac80211/patches/540-ath9k_fix_survey_crash.patch
new file mode 100644
index 0000000000..b627f8f4a8
--- /dev/null
+++ b/package/mac80211/patches/540-ath9k_fix_survey_crash.patch
@@ -0,0 +1,12 @@
+--- a/drivers/net/wireless/ath/ath9k/main.c
++++ b/drivers/net/wireless/ath/ath9k/main.c
+@@ -183,6 +183,9 @@ static void ath_update_survey_stats(stru
+ 	struct ath_cycle_counters *cc = &common->cc_survey;
+ 	unsigned int div = common->clockrate * 1000;
+ 
++	if (!ah->curchan)
++		return;
++
+ 	if (ah->power_mode == ATH9K_PM_AWAKE)
+ 		ath_hw_cycle_counters_update(common);
+