From 05cf68cf4c22bc503c5f76304788e219d9079761 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@openwrt.org>
Date: Wed, 25 Aug 2010 12:30:50 +0000
Subject: [PATCH] ath9k: fix spurious MIC failure detection, causing
 instability issues in AP mode

SVN-Revision: 22795
---
 .../patches/570-ath9k_mic_failure_fix.patch   | 74 +++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 package/mac80211/patches/570-ath9k_mic_failure_fix.patch

diff --git a/package/mac80211/patches/570-ath9k_mic_failure_fix.patch b/package/mac80211/patches/570-ath9k_mic_failure_fix.patch
new file mode 100644
index 00000000000..73c6347c5c0
--- /dev/null
+++ b/package/mac80211/patches/570-ath9k_mic_failure_fix.patch
@@ -0,0 +1,74 @@
+--- a/drivers/net/wireless/ath/ath.h
++++ b/drivers/net/wireless/ath/ath.h
+@@ -119,6 +119,7 @@ struct ath_common {
+ 
+ 	u32 keymax;
+ 	DECLARE_BITMAP(keymap, ATH_KEYMAX);
++	DECLARE_BITMAP(tkip_keymap, ATH_KEYMAX);
+ 	u8 splitmic;
+ 
+ 	struct ath_regulatory regulatory;
+--- a/drivers/net/wireless/ath/ath9k/common.c
++++ b/drivers/net/wireless/ath/ath9k/common.c
+@@ -366,9 +366,13 @@ int ath9k_cmn_key_config(struct ath_comm
+ 	set_bit(idx, common->keymap);
+ 	if (key->alg == ALG_TKIP) {
+ 		set_bit(idx + 64, common->keymap);
++		set_bit(idx, common->tkip_keymap);
++		set_bit(idx + 64, common->tkip_keymap);
+ 		if (common->splitmic) {
+ 			set_bit(idx + 32, common->keymap);
+ 			set_bit(idx + 64 + 32, common->keymap);
++			set_bit(idx + 32, common->tkip_keymap);
++			set_bit(idx + 64 + 32, common->tkip_keymap);
+ 		}
+ 	}
+ 
+@@ -393,10 +397,17 @@ void ath9k_cmn_key_delete(struct ath_com
+ 		return;
+ 
+ 	clear_bit(key->hw_key_idx + 64, common->keymap);
++
++	clear_bit(key->hw_key_idx, common->tkip_keymap);
++	clear_bit(key->hw_key_idx + 64, common->tkip_keymap);
++
+ 	if (common->splitmic) {
+ 		ath9k_hw_keyreset(ah, key->hw_key_idx + 32);
+ 		clear_bit(key->hw_key_idx + 32, common->keymap);
+ 		clear_bit(key->hw_key_idx + 64 + 32, common->keymap);
++
++		clear_bit(key->hw_key_idx + 32, common->tkip_keymap);
++		clear_bit(key->hw_key_idx + 64 + 32, common->tkip_keymap);
+ 	}
+ }
+ EXPORT_SYMBOL(ath9k_cmn_key_delete);
+--- a/drivers/net/wireless/ath/ath9k/recv.c
++++ b/drivers/net/wireless/ath/ath9k/recv.c
+@@ -870,15 +870,19 @@ static bool ath9k_rx_accept(struct ath_c
+ 		if (rx_stats->rs_status & ATH9K_RXERR_DECRYPT) {
+ 			*decrypt_error = true;
+ 		} else if (rx_stats->rs_status & ATH9K_RXERR_MIC) {
+-			if (ieee80211_is_ctl(fc))
+-				/*
+-				 * Sometimes, we get invalid
+-				 * MIC failures on valid control frames.
+-				 * Remove these mic errors.
+-				 */
+-				rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
+-			else
++			/*
++			 * The MIC error bit is only valid if the frame
++			 * is not a control frame, and it was decrypted using
++			 * a TKIP key.
++			 */
++			if (!ieee80211_is_ctl(fc) &&
++			    rx_stats->rs_keyix != ATH9K_RXKEYIX_INVALID &&
++			    test_bit(rx_stats->rs_keyix, common->tkip_keymap)) {
+ 				rxs->flag |= RX_FLAG_MMIC_ERROR;
++			} else {
++				rx_stats->rs_status &= ~ATH9K_RXERR_MIC;
++				*decrypt_error = true;
++			}
+ 		}
+ 		/*
+ 		 * Reject error frames with the exception of
-- 
2.30.2