ath9k: fix rx flush handling

Right now the rx flush is not doing anything useful on AR9003+, as it only
works if the buffers in the rx FIFO have not been purged yet, as is done
by ath_stoprecv.

To fix this, always call ath_flushrecv from within ath_stoprecv before
the FIFO is emptied, but still after the hw receive path has been stopped.

This ensures that frames received (and ACKed by the hardware) shortly before
a reset will be seen by the software, which should improve A-MPDU session
stability.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index d3cf01e..9844b75 100644
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -182,7 +182,7 @@
 	ath_start_ani(sc);
 }
 
-static bool ath_prepare_reset(struct ath_softc *sc, bool retry_tx, bool flush)
+static bool ath_prepare_reset(struct ath_softc *sc, bool retry_tx)
 {
 	struct ath_hw *ah = sc->sc_ah;
 	bool ret = true;
@@ -204,14 +204,6 @@
 	if (!ath_drain_all_txq(sc, retry_tx))
 		ret = false;
 
-	if (!flush) {
-		if (ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
-			ath_rx_tasklet(sc, 1, true);
-		ath_rx_tasklet(sc, 1, false);
-	} else {
-		ath_flushrecv(sc);
-	}
-
 	tasklet_enable(&sc->intr_tq);
 
 	return ret;
@@ -266,7 +258,6 @@
 	struct ath_common *common = ath9k_hw_common(ah);
 	struct ath9k_hw_cal_data *caldata = NULL;
 	bool fastcc = true;
-	bool flush = false;
 	int r;
 
 	__ath_cancel_work(sc);
@@ -280,11 +271,10 @@
 
 	if (!hchan) {
 		fastcc = false;
-		flush = true;
 		hchan = ah->curchan;
 	}
 
-	if (!ath_prepare_reset(sc, retry_tx, flush))
+	if (!ath_prepare_reset(sc, retry_tx))
 		fastcc = false;
 
 	ath_dbg(common, CONFIG, "Reset to %u MHz, HT40: %d fastcc: %d\n",
@@ -808,7 +798,7 @@
 		ath9k_hw_cfg_gpio_input(ah, ah->led_pin);
 	}
 
-	ath_prepare_reset(sc, false, true);
+	ath_prepare_reset(sc, false);
 
 	if (sc->rx.frag) {
 		dev_kfree_skb_any(sc->rx.frag);