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

commit 7fc00a3054b70b1794c2d64db703eb467ad0365c upstream.

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.

Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index dfe6a4707fd22684a5994de3b6c4d9dcadd456f2..549dde270cb7620d5f7069c0cdfb280f8d4ea5a4 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -630,7 +630,6 @@ void ath_ant_comb_update(struct ath_softc *sc);
 enum sc_op_flags {
        SC_OP_INVALID,
        SC_OP_BEACONS,
-       SC_OP_RXFLUSH,
        SC_OP_ANI_RUN,
        SC_OP_PRIM_STA_VIF,
        SC_OP_HW_RESET,

diff --git a/drivers/net/wireless/ath/ath9k/debug.c b/drivers/net/wireless/ath/ath9k/debug.c
index 6727b566d294a43073c2a4cf3cc532f0e633b34e..774e95bdd1630bea51da6fa446e07e77b649fb09 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -973,7 +973,6 @@ static ssize_t read_file_recv(struct file *file, char __user *user_buf,
        RXS_ERR("RX-LENGTH-ERR", rx_len_err);
        RXS_ERR("RX-OOM-ERR", rx_oom_err);
        RXS_ERR("RX-RATE-ERR", rx_rate_err);
-       RXS_ERR("RX-DROP-RXFLUSH", rx_drop_rxflush);
        RXS_ERR("RX-TOO-MANY-FRAGS", rx_too_many_frags_err);
 
        PHY_ERR("UNDERRUN ERR", ATH9K_PHYERR_UNDERRUN);

diff --git a/drivers/net/wireless/ath/ath9k/debug.h b/drivers/net/wireless/ath/ath9k/debug.h
index 2ed9785a38fa0467a8ab8be32d30c912a5194a87..b9d95c70b6df828fdd5207fde27981835e9548dc 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/debug.h
+++ b/drivers/net/wireless/ath/ath9k/debug.h
@@ -200,7 +200,6 @@ struct ath_tx_stats {
  * @rx_oom_err:  No. of frames dropped due to OOM issues.
  * @rx_rate_err:  No. of frames dropped due to rate errors.
  * @rx_too_many_frags_err:  Frames dropped due to too-many-frags received.
- * @rx_drop_rxflush: No. of frames dropped due to RX-FLUSH.
  * @rx_beacons:  No. of beacons received.
  * @rx_frags:  No. of rx-fragements received.
  */
@@ -219,7 +218,6 @@ struct ath_rx_stats {
        u32 rx_oom_err;
        u32 rx_rate_err;
        u32 rx_too_many_frags_err;
-       u32 rx_drop_rxflush;
        u32 rx_beacons;
        u32 rx_frags;
 };

diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
index dd45edfa6baec25304af0a07ccea22f1c0910f29..2f98d3ac4440ec728e4ce6e7e0f6b9b0ed506b91 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -195,6 +195,8 @@ static bool ath_prepare_reset(struct ath_softc *sc, bool retry_tx, bool flush)
        ath9k_debug_samp_bb_mac(sc);
        ath9k_hw_disable_interrupts(ah);
 
+       tasklet_disable(&sc->intr_tq);
+
        if (!ath_stoprecv(sc))
                ret = false;
 
@@ -209,6 +211,8 @@ static bool ath_prepare_reset(struct ath_softc *sc, bool retry_tx, bool flush)
                ath_flushrecv(sc);
        }
 
+       tasklet_enable(&sc->intr_tq);
+
        return ret;
 }
 

diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c
index 2ed489780d75c410ae58b4c9492114eac8498978..55393aa14bafbc7d9df3e94bf765e8e0fcded394 100644 (file)
--- 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)
@@ -1109,15 +1103,6 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp)
                sc->rx.num_pkts++;
                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;