[PATCH] ath9k: Fix enabling OFDM weak signal detection

[Steven Luo <steven@steven676.net>]

From: Steven Luo <steven@steven676.net>

It seems that OFDM weak signal detection should be enabled after an ANI
state reset, as indicated by the initial setting of ofdmWeakSigDetectOff
and what the open Atheros HAL does.  Unfortunately, the reversed sense
of ofdmWeakSigDetectOff (true if weak signal detection is NOT enabled)
seems to have resulted in a mixup here, causing weak signal detection to
be disabled.

This patch significantly improves reception and throughput from distant
stations for my AR5416-based AP running compat-wireless 2009-06-25.

Signed-off-by: Steven Luo <steven@steven676.net>
Cc: stable@kernel.org
---

--- a/drivers/net/wireless/ath/ath9k/ani.c	2009-06-24 21:14:00.000000000 -0700
+++ b/drivers/net/wireless/ath/ath9k/ani.c	2009-07-06 02:45:57.000000000 -0700
@@ -482,7 +482,7 @@ void ath9k_ani_reset(struct ath_hw *ah)
 		ath9k_hw_ani_control(ah, ATH9K_ANI_SPUR_IMMUNITY_LEVEL, 0);
 		ath9k_hw_ani_control(ah, ATH9K_ANI_FIRSTEP_LEVEL, 0);
 		ath9k_hw_ani_control(ah, ATH9K_ANI_OFDM_WEAK_SIGNAL_DETECTION,
-				     !ATH9K_ANI_USE_OFDM_WEAK_SIG);
+				     ATH9K_ANI_USE_OFDM_WEAK_SIG);
 		ath9k_hw_ani_control(ah, ATH9K_ANI_CCK_WEAK_SIGNAL_THR,
 				     ATH9K_ANI_CCK_WEAK_SIG_THR);