ath9k: make DMA stop related messages debug-only

A long time ago, ath9k had issues during reset where the DMA engine
would stay active and could potentially corrupt memory.
To debug those issues, the driver would print warnings whenever they
occur.

Nowadays, these issues are gone and the primary cause of these messages
is if the MAC is stuck during reset or busy processing a long
transmission. This is fairly harmless, yet these messages continue to
worry users.

To reduce the number of bogus bug reports, turn these messages into
debug messages and count their occurence in the "reset" debugfs file.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index dbf8f49..da32c8f 100644
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -765,6 +765,8 @@
 		[RESET_TYPE_BEACON_STUCK] = "Stuck Beacon",
 		[RESET_TYPE_MCI] = "MCI Reset",
 		[RESET_TYPE_CALIBRATION] = "Calibration error",
+		[RESET_TX_DMA_ERROR] = "Tx DMA stop error",
+		[RESET_RX_DMA_ERROR] = "Rx DMA stop error",
 	};
 	int i;
 
diff --git a/drivers/net/wireless/ath/ath9k/debug.h b/drivers/net/wireless/ath/ath9k/debug.h
index a8e9319..cd68c5f 100644
--- a/drivers/net/wireless/ath/ath9k/debug.h
+++ b/drivers/net/wireless/ath/ath9k/debug.h
@@ -50,6 +50,8 @@
 	RESET_TYPE_BEACON_STUCK,
 	RESET_TYPE_MCI,
 	RESET_TYPE_CALIBRATION,
+	RESET_TX_DMA_ERROR,
+	RESET_RX_DMA_ERROR,
 	__RESET_TYPE_MAX
 };
 
diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 6c75fb1..d3189da 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -491,10 +491,9 @@
 
 	if (!(ah->ah_flags & AH_UNPLUGGED) &&
 	    unlikely(!stopped)) {
-		ath_err(ath9k_hw_common(sc->sc_ah),
-			"Could not stop RX, we could be "
-			"confusing the DMA engine when we start RX up\n");
-		ATH_DBG_WARN_ON_ONCE(!stopped);
+		ath_dbg(ath9k_hw_common(sc->sc_ah), RESET,
+			"Failed to stop Rx DMA\n");
+		RESET_STAT_INC(sc, RESET_RX_DMA_ERROR);
 	}
 	return stopped && !reset;
 }
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index 3ad79bb..2c627f1 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -1883,8 +1883,11 @@
 			npend |= BIT(i);
 	}
 
-	if (npend)
-		ath_err(common, "Failed to stop TX DMA, queues=0x%03x!\n", npend);
+	if (npend) {
+		RESET_STAT_INC(sc, RESET_TX_DMA_ERROR);
+		ath_dbg(common, RESET,
+			"Failed to stop TX DMA, queues=0x%03x!\n", npend);
+	}
 
 	for (i = 0; i < ATH9K_NUM_TX_QUEUES; i++) {
 		if (!ATH_TXQ_SETUP(sc, i))