ath9k: merge fix for noise floor calibration

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

SVN-Revision: 48641

1 files changed, 87 insertions, 0 deletions

diff --git a/package/kernel/mac80211/patches/326-ath9k-make-NF-load-complete-quickly-and-reliably.patch b/package/kernel/mac80211/patches/326-ath9k-make-NF-load-complete-quickly-and-reliably.patch
new file mode 100644
index 0000000000..71f7a40433
--- /dev/null
+++ b/package/kernel/mac80211/patches/326-ath9k-make-NF-load-complete-quickly-and-reliably.patch
@@ -0,0 +1,87 @@
+From: Miaoqing Pan <miaoqing@codeaurora.org>
+Date: Fri, 5 Feb 2016 09:45:50 +0800
+Subject: [PATCH] ath9k: make NF load complete quickly and reliably
+
+Make NF load complete quickly and reliably. NF load execution
+is delayed by HW to end of frame if frame Rx or Tx is ongoing.
+Increasing timeout to max frame duration. If NF cal is ongoing
+before NF load, stop it before load, and restart it afterwards.
+
+Signed-off-by: Miaoqing Pan <miaoqing@codeaurora.org>
+---
+
+--- a/drivers/net/wireless/ath/ath9k/calib.c
++++ b/drivers/net/wireless/ath/ath9k/calib.c
+@@ -241,6 +241,7 @@ int ath9k_hw_loadnf(struct ath_hw *ah, s
+ 	u8 chainmask = (ah->rxchainmask << 3) | ah->rxchainmask;
+ 	struct ath_common *common = ath9k_hw_common(ah);
+ 	s16 default_nf = ath9k_hw_get_default_nf(ah, chan);
++	u32 bb_agc_ctl = REG_READ(ah, AR_PHY_AGC_CONTROL);
+ 
+ 	if (ah->caldata)
+ 		h = ah->caldata->nfCalHist;
+@@ -264,6 +265,16 @@ int ath9k_hw_loadnf(struct ath_hw *ah, s
+ 	}
+ 
+ 	/*
++	 * stop NF cal if ongoing to ensure NF load completes immediately
++	 * (or after end rx/tx frame if ongoing)
++	 */
++	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
++		REG_CLR_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
++		REG_RMW_BUFFER_FLUSH(ah);
++		ENABLE_REG_RMW_BUFFER(ah);
++	}
++
++	/*
+ 	 * Load software filtered NF value into baseband internal minCCApwr
+ 	 * variable.
+ 	 */
+@@ -276,18 +287,33 @@ int ath9k_hw_loadnf(struct ath_hw *ah, s
+ 
+ 	/*
+ 	 * Wait for load to complete, should be fast, a few 10s of us.
+-	 * The max delay was changed from an original 250us to 10000us
+-	 * since 250us often results in NF load timeout and causes deaf
+-	 * condition during stress testing 12/12/2009
++	 * The max delay was changed from an original 250us to 22.2 msec.
++	 * This would increase timeout to the longest possible frame
++	 * (11n max length 22.1 msec)
+ 	 */
+-	for (j = 0; j < 10000; j++) {
++	for (j = 0; j < 22200; j++) {
+ 		if ((REG_READ(ah, AR_PHY_AGC_CONTROL) &
+-		     AR_PHY_AGC_CONTROL_NF) == 0)
++			      AR_PHY_AGC_CONTROL_NF) == 0)
+ 			break;
+ 		udelay(10);
+ 	}
+ 
+ 	/*
++	 * Restart NF so it can continue.
++	 */
++	if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NF) {
++		ENABLE_REG_RMW_BUFFER(ah);
++		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_ENABLE_NF)
++			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
++				    AR_PHY_AGC_CONTROL_ENABLE_NF);
++		if (bb_agc_ctl & AR_PHY_AGC_CONTROL_NO_UPDATE_NF)
++			REG_SET_BIT(ah, AR_PHY_AGC_CONTROL,
++				    AR_PHY_AGC_CONTROL_NO_UPDATE_NF);
++		REG_SET_BIT(ah, AR_PHY_AGC_CONTROL, AR_PHY_AGC_CONTROL_NF);
++		REG_RMW_BUFFER_FLUSH(ah);
++	}
++
++	/*
+ 	 * We timed out waiting for the noisefloor to load, probably due to an
+ 	 * in-progress rx. Simply return here and allow the load plenty of time
+ 	 * to complete before the next calibration interval.  We need to avoid
+@@ -296,7 +322,7 @@ int ath9k_hw_loadnf(struct ath_hw *ah, s
+ 	 * here, the baseband nf cal will just be capped by our present
+ 	 * noisefloor until the next calibration timer.
+ 	 */
+-	if (j == 10000) {
++	if (j == 22200) {
+ 		ath_dbg(common, ANY,
+ 			"Timeout while waiting for nf to load: AR_PHY_AGC_CONTROL=0x%x\n",
+ 			REG_READ(ah, AR_PHY_AGC_CONTROL));