There's apparently a bug with Merlin (AR9280) and later chipsets where

putting descriptors (not buffers) across a 4k page boundary can cause issues.
I've not seen it in production myself but it apparently can cause problems.

So, in preparation for addressing this workaround, (re)-expose the particular
HAL capability bit which marks whether the chipset has support for cross-4k-
boundary transactions or not.

A subsequent commit will modify the descriptor allocation to avoid allocating
descriptor entries that straddle a 4k page boundary.

6 files changed, 8 insertions, 5 deletions

diff --git a/sys/dev/ath/ath_hal/ah_internal.h b/sys/dev/ath/ath_hal/ah_internal.h
index f3fd9e8..2caf5cc 100644
--- a/sys/dev/ath/ath_hal/ah_internal.h
+++ b/sys/dev/ath/ath_hal/ah_internal.h
@@ -195,7 +195,8 @@ typedef struct {
 			halForcePpmSupport		: 1,
 			halEnhancedPmSupport		: 1,
 			halMbssidAggrSupport		: 1,
-			halBssidMatchSupport		: 1;
+			halBssidMatchSupport		: 1,
+			hal4kbSplitTransSupport		: 1;
 	uint32_t	halWirelessModes;
 	uint16_t	halTotalQueues;
 	uint16_t	halKeyCacheSize;
diff --git a/sys/dev/ath/ath_hal/ar5210/ar5210_attach.c b/sys/dev/ath/ath_hal/ar5210/ar5210_attach.c
index c76e188..e1a5067 100644
--- a/sys/dev/ath/ath_hal/ar5210/ar5210_attach.c
+++ b/sys/dev/ath/ath_hal/ar5210/ar5210_attach.c
@@ -377,6 +377,8 @@ ar5210FillCapabilityInfo(struct ath_hal *ah)
 			| HAL_INT_FATAL
 			;
 
+	pCap->hal4kbSplitTransSupport = AH_TRUE;
+
 	ahpriv->ah_rxornIsFatal = AH_TRUE;
 	return AH_TRUE;
 }
diff --git a/sys/dev/ath/ath_hal/ar5211/ar5211_attach.c b/sys/dev/ath/ath_hal/ar5211/ar5211_attach.c
index fe87fce..bace648 100644
--- a/sys/dev/ath/ath_hal/ar5211/ar5211_attach.c
+++ b/sys/dev/ath/ath_hal/ar5211/ar5211_attach.c
@@ -509,6 +509,8 @@ ar5211FillCapabilityInfo(struct ath_hal *ah)
 			| HAL_INT_TIM
 			;
 
+	pCap->hal4kbSplitTransSupport = AH_TRUE;
+
 	/* XXX might be ok w/ some chip revs */
 	ahpriv->ah_rxornIsFatal = AH_TRUE;
 	return AH_TRUE;
diff --git a/sys/dev/ath/ath_hal/ar5212/ar5212_attach.c b/sys/dev/ath/ath_hal/ar5212/ar5212_attach.c
index 9a2bc70..3aabdcc 100644
--- a/sys/dev/ath/ath_hal/ar5212/ar5212_attach.c
+++ b/sys/dev/ath/ath_hal/ar5212/ar5212_attach.c
@@ -860,6 +860,8 @@ ar5212FillCapabilityInfo(struct ath_hal *ah)
 	if (AH_PRIVATE(ah)->ah_macVersion < AR_SREV_VERSION_GRIFFIN)
 		pCap->halIntrMask &= ~HAL_INT_TBTT;
 
+	pCap->hal4kbSplitTransSupport = AH_TRUE;
+
 	return AH_TRUE;
 #undef IS_COBRA
 #undef IS_GRIFFIN_LITE
diff --git a/sys/dev/ath/ath_hal/ar9002/ar9280_attach.c b/sys/dev/ath/ath_hal/ar9002/ar9280_attach.c
index 698f9a9..80281d8 100644
--- a/sys/dev/ath/ath_hal/ar9002/ar9280_attach.c
+++ b/sys/dev/ath/ath_hal/ar9002/ar9280_attach.c
@@ -698,9 +698,7 @@ ar9280FillCapabilityInfo(struct ath_hal *ah)
 	pCap->halBtCoexSupport = AH_TRUE;
 #endif
 	pCap->halAutoSleepSupport = AH_FALSE;	/* XXX? */
-#if 0
 	pCap->hal4kbSplitTransSupport = AH_FALSE;
-#endif
 	pCap->halRxStbcSupport = 1;
 	pCap->halTxStbcSupport = 1;
 
diff --git a/sys/dev/ath/ath_hal/ar9002/ar9285_attach.c b/sys/dev/ath/ath_hal/ar9002/ar9285_attach.c
index d62d0e6..ee65841 100644
--- a/sys/dev/ath/ath_hal/ar9002/ar9285_attach.c
+++ b/sys/dev/ath/ath_hal/ar9002/ar9285_attach.c
@@ -384,9 +384,7 @@ ar9285FillCapabilityInfo(struct ath_hal *ah)
 	pCap->halBtCoexSupport = AH_TRUE;
 #endif
 	pCap->halAutoSleepSupport = AH_FALSE;	/* XXX? */
-#if 0
 	pCap->hal4kbSplitTransSupport = AH_FALSE;
-#endif
 	pCap->halRxStbcSupport = 1;
 	pCap->halTxStbcSupport = 1;