[ 39/89] ath9k: fix rx flush handling

From: Greg Kroah-Hartman
Date: Fri Feb 01 2013 - 08:11:12 EST


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

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

From: Felix Fietkau <nbd@xxxxxxxxxxx>

commit 4b883f021b9ccf2df3d14425e6e610281fb6a35e upstream.

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.

Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/net/wireless/ath/ath9k/ath9k.h | 1 -
drivers/net/wireless/ath/ath9k/main.c | 16 +++-------------
drivers/net/wireless/ath/ath9k/recv.c | 16 +++++++++-------
3 files changed, 12 insertions(+), 21 deletions(-)

--- a/drivers/net/wireless/ath/ath9k/ath9k.h
+++ b/drivers/net/wireless/ath/ath9k/ath9k.h
@@ -326,7 +326,6 @@ struct ath_rx {

int ath_startrecv(struct ath_softc *sc);
bool ath_stoprecv(struct ath_softc *sc);
-void ath_flushrecv(struct ath_softc *sc);
u32 ath_calcrxfilter(struct ath_softc *sc);
int ath_rx_init(struct ath_softc *sc, int nbufs);
void ath_rx_cleanup(struct ath_softc *sc);
--- a/drivers/net/wireless/ath/ath9k/main.c
+++ b/drivers/net/wireless/ath/ath9k/main.c
@@ -181,7 +181,7 @@ static void ath_restart_work(struct ath_
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;
@@ -203,14 +203,6 @@ static bool ath_prepare_reset(struct ath
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;
@@ -265,7 +257,6 @@ static int ath_reset_internal(struct ath
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);
@@ -279,11 +270,10 @@ static int ath_reset_internal(struct ath

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",
@@ -820,7 +810,7 @@ static void ath9k_stop(struct ieee80211_
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);
--- a/drivers/net/wireless/ath/ath9k/recv.c
+++ b/drivers/net/wireless/ath/ath9k/recv.c
@@ -472,6 +472,13 @@ start_recv:
return 0;
}

+static void ath_flushrecv(struct ath_softc *sc)
+{
+ if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
+ ath_rx_tasklet(sc, 1, true);
+ ath_rx_tasklet(sc, 1, false);
+}
+
bool ath_stoprecv(struct ath_softc *sc)
{
struct ath_hw *ah = sc->sc_ah;
@@ -482,6 +489,8 @@ bool ath_stoprecv(struct ath_softc *sc)
ath9k_hw_setrxfilter(ah, 0);
stopped = ath9k_hw_stopdmarecv(ah, &reset);

+ ath_flushrecv(sc);
+
if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
ath_edma_stop_recv(sc);
else
@@ -498,13 +507,6 @@ bool ath_stoprecv(struct ath_softc *sc)
return stopped && !reset;
}

-void ath_flushrecv(struct ath_softc *sc)
-{
- if (sc->sc_ah->caps.hw_caps & ATH9K_HW_CAP_EDMA)
- ath_rx_tasklet(sc, 1, true);
- ath_rx_tasklet(sc, 1, false);
-}
-
static bool ath_beacon_dtim_pending_cab(struct sk_buff *skb)
{
/* Check whether the Beacon frame has DTIM indicating buffered bc/mc */


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