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>

diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h
index 86e26a19efdac1923395543c1a50fb53a6cb8958..7335e9ef0249e3d3f3f19cbd574fe5b477b159f6 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -646,7 +646,6 @@ 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 13ff9edc24015e5e2126fc4f6c7fde8dcb003c90..e585fc827c50b2e9d5ff2fe08afb15cd49cedba6 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/debug.c
+++ b/drivers/net/wireless/ath/ath9k/debug.c
@@ -861,7 +861,6 @@ 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 375c3b46411eee6cd140dbc22e6e435fe0e32ad9..6df2ab62dcb706df5bef4a8afdf04593651f111a 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/debug.h
+++ b/drivers/net/wireless/ath/ath9k/debug.h
@@ -216,7 +216,6 @@ 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.
  */
@@ -235,7 +234,6 @@ 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 be30a9af152884d8e073b7a3be5b79e6b3d5a8ee..d3cf01ec2d15093ec41660d569d339665d9803b7 100644 (file)
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -196,6 +196,8 @@ 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;
 
@@ -210,6 +212,8 @@ 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 01c3ba47a5b9535c0ed902f1a3d019f025172964..6b83b3bbfe8c8021177ea9f6e20edc64ac190032 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)
@@ -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;