ath9k: improve reliability of beacon transmission and stuck beacon handling

ath9k calls ath9k_hw_stoptxdma every time it sends a beacon, however there
is not much point in doing that if the previous beacon and mcast traffic
went out properly. On AR9380, calling that function too often can result
in an increase of stuck beacons due to differences in the handling of the
queue enable/disable functionality.

With this patch, the queue will only be explicitly stopped if the previous
data frames were not sent successfully. With the beacon code being the
only remaining user of ath9k_hw_stoptxdma, this function can be simplified
in order to remove the now pointless attempts at waiting for transmission
completion, which would never happen at this point due to the different
method of tx scheduling of the beacon queue.

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

1 files changed, 2 insertions, 11 deletions

diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
index a4bdfdb043ef..6d2a545fc35e 100644
--- a/drivers/net/wireless/ath/ath9k/beacon.c
+++ b/drivers/net/wireless/ath/ath9k/beacon.c
@@ -373,6 +373,7 @@ void ath_beacon_tasklet(unsigned long data)
 			ath_dbg(common, ATH_DBG_BSTUCK,
 				"missed %u consecutive beacons\n",
 				sc->beacon.bmisscnt);
+			ath9k_hw_stop_dma_queue(ah, sc->beacon.beaconq);
 			ath9k_hw_bstuck_nfcal(ah);
 		} else if (sc->beacon.bmisscnt >= BSTUCK_THRESH) {
 			ath_dbg(common, ATH_DBG_BSTUCK,
@@ -450,16 +451,6 @@ void ath_beacon_tasklet(unsigned long data)
 		sc->beacon.updateslot = OK;
 	}
 	if (bfaddr != 0) {
-		/*
-		 * Stop any current dma and put the new frame(s) on the queue.
-		 * This should never fail since we check above that no frames
-		 * are still pending on the queue.
-		 */
-		if (!ath9k_hw_stoptxdma(ah, sc->beacon.beaconq)) {
-			ath_err(common, "beacon queue %u did not stop?\n",
-				sc->beacon.beaconq);
-		}
-
 		/* NB: cabq traffic should already be queued and primed */
 		ath9k_hw_puttxbuf(ah, sc->beacon.beaconq, bfaddr);
 		ath9k_hw_txstart(ah, sc->beacon.beaconq);
@@ -780,7 +771,7 @@ void ath9k_set_beaconing_status(struct ath_softc *sc, bool status)
 		ah->imask &= ~ATH9K_INT_SWBA;
 		ath9k_hw_set_interrupts(ah, ah->imask);
 		tasklet_kill(&sc->bcon_tasklet);
-		ath9k_hw_stoptxdma(ah, sc->beacon.beaconq);
+		ath9k_hw_stop_dma_queue(ah, sc->beacon.beaconq);
 	}
 	ath9k_ps_restore(sc);
 }