[PATCH 3.19.y-ckt 087/251] ath9k: fix DMA stop sequence for AR9003+

[Kamal Mostafa]

3.19.8-ckt4 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Felix Fietkau <nbd at openwrt.org>

commit 300f77c08ded96d33f492aaa02549103852f0c12 upstream.

AR93xx and newer needs to stop rx before tx to avoid getting the DMA
engine or MAC into a stuck state.
This should reduce/fix the occurence of "Failed to stop Tx DMA" logspam.

Signed-off-by: Felix Fietkau <nbd at openwrt.org>
Signed-off-by: Kalle Valo <kvalo at codeaurora.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/net/wireless/ath/ath9k/main.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index 62b0bf4..cea94dbf 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -216,11 +216,13 @@ static bool ath_prepare_reset(struct ath_softc *sc)
 	ath_stop_ani(sc);
 	ath9k_hw_disable_interrupts(ah);
 
-	if (!ath_drain_all_txq(sc))
-		ret = false;
-
-	if (!ath_stoprecv(sc))
-		ret = false;
+	if (AR_SREV_9300_20_OR_LATER(ah)) {
+		ret &= ath_stoprecv(sc);
+		ret &= ath_drain_all_txq(sc);
+	} else {
+		ret &= ath_drain_all_txq(sc);
+		ret &= ath_stoprecv(sc);
+	}
 
 	return ret;
 }
-- 
1.9.1