From: Luis R. Rodriguez Date: Wed, 20 Oct 2010 23:07:04 +0000 (-0700) Subject: ath9k: add locking for starting the PCU on RX X-Git-Tag: firefly_0821_release~9833^2~79^2^2~253 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=43d7d3dec4052bb98790a26f67abbb01b5e1b9f3;p=firefly-linux-kernel-4.4.55.git ath9k: add locking for starting the PCU on RX commit 7583c550c3e635dcc61ab127c36ecefd59fb8dc8 upstream. There was some locking for starting some parts of RX but not for starting the PCU. Include this otherwise we can content against stopping the PCU. This can potentially lead to races against different buffers on the PCU which can lead to to the DMA RX engine writing to buffers which are already freed. This is part of a series that will help resolve the bug: https://bugzilla.kernel.org/show_bug.cgi?id=14624 For more details about this issue refer to: http://marc.info/?l=linux-wireless&m=128629803703756&w=2 Cc: Ben Greear Cc: Kyungwan Nam Signed-off-by: Luis R. Rodriguez Tested-by: Ben Greear Signed-off-by: John W. Linville Signed-off-by: Greg Kroah-Hartman index e581b1f..b3c9baf 100644 --- diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index 8b1b459447d2..2a2b3f734000 100644 --- a/drivers/net/wireless/ath/ath9k/recv.c +++ b/drivers/net/wireless/ath/ath9k/recv.c @@ -288,11 +288,11 @@ static void ath_edma_start_recv(struct ath_softc *sc) ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_LP, sc->rx.rx_edma[ATH9K_RX_QUEUE_LP].rx_fifo_hwsize); - spin_unlock_bh(&sc->rx.rxbuflock); - ath_opmode_init(sc); ath9k_hw_startpcureceive(sc->sc_ah, (sc->sc_flags & SC_OP_OFFCHANNEL)); + + spin_unlock_bh(&sc->rx.rxbuflock); } static void ath_edma_stop_recv(struct ath_softc *sc) @@ -494,10 +494,11 @@ int ath_startrecv(struct ath_softc *sc) ath9k_hw_rxena(ah); start_recv: - spin_unlock_bh(&sc->rx.rxbuflock); ath_opmode_init(sc); ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL)); + spin_unlock_bh(&sc->rx.rxbuflock); + return 0; }