ath9k: add a better fix for the rx tasklet vs rx flush race

Ensure that the rx tasklet is no longer running when entering the reset path.
Also remove the distinction between flush and no-flush frame processing.
If a frame has been received and ACKed by the hardware, the stack needs to see
it, so that the BA receive window does not go out of sync.

Cc: stable@vger.kernel.org
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 0 insertions, 15 deletions

diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 01c3ba47a5b9..6b83b3bbfe8c 100644
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -286,7 +286,6 @@ int ath_rx_init(struct ath_softc *sc, int nbufs)
 
         spin_lock_init(&sc->sc_pcu_lock);
         spin_lock_init(&sc->rx.rxbuflock);
-        clear_bit(SC_OP_RXFLUSH, &sc->sc_flags);
 
         common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 +
                              sc->sc_ah->caps.rx_status_len;
@@ -501,11 +500,9 @@ bool ath_stoprecv(struct ath_softc *sc)
 
 void ath_flushrecv(struct ath_softc *sc)
 {
-        set_bit(SC_OP_RXFLUSH, &sc->sc_flags);
         if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
                 ath_rx_tasklet(sc, 1, true);
         ath_rx_tasklet(sc, 1, false);
-        clear_bit(SC_OP_RXFLUSH, &sc->sc_flags);
 }
 
 static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
@@ -1067,9 +1064,6 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 
         do {
                 bool decrypt_error = false;
-                /* If handling rx interrupt and flush is in progress => exit */
-                if (test_bit(SC_OP_RXFLUSH, &sc->sc_flags) && (flush == 0))
-                        break;
 
                 memset(&rs, 0, sizeof(rs));
                 if (edma)
@@ -1112,15 +1106,6 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
 
                 ath_debug_stat_rx(sc, &rs);
 
-                /*
-                 * If we're asked to flush receive queue, directly
-                 * chain it back at the queue without processing it.
-                 */
-                if (test_bit(SC_OP_RXFLUSH, &sc->sc_flags)) {
-                        RX_STAT_INC(rx_drop_rxflush);
-                        goto requeue_drop_frag;
-                }
-
                 memset(rxs, 0, sizeof(struct ieee80211_rx_status));
 
                 rxs->mactime = (tsf & ~0xffffffffULL) | rs.rs_tstamp;