| From | Herton Ronaldo Krzesinski <> | Subject | [PATCH 38/93] ath9k: remove sc->rx.rxbuflock to fix a deadlock | Date | Tue, 5 Feb 2013 20:06:27 -0200 |
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3.5.7.5 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Felix Fietkau <nbd@openwrt.org>
commit 463e3ed3eacc8f47866e5d612bd8ee0bcee5e2f0 upstream.
The commit "ath9k: fix rx flush handling" added a deadlock that happens because ath_rx_tasklet is called in a section that has already taken the rx buffer lock.
It seems that the only purpose of the rxbuflock was a band-aid fix to the reset vs rx tasklet race, which has been properly fixed in the commit "ath9k: add a better fix for the rx tasklet vs rx flush race".
Now that the fix is in, we can safely remove the lock to avoid such issues.
Reported-by: Sujith Manoharan <c_manoha@qca.qualcomm.com> Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com> [ herton: adjust context ] Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- drivers/net/wireless/ath/ath9k/ath9k.h | 1 - drivers/net/wireless/ath/ath9k/recv.c | 13 ------------- 2 files changed, 14 deletions(-)
diff --git a/drivers/net/wireless/ath/ath9k/ath9k.h b/drivers/net/wireless/ath/ath9k/ath9k.h index 8697014..e9a14c0 100644 --- a/drivers/net/wireless/ath/ath9k/ath9k.h +++ b/drivers/net/wireless/ath/ath9k/ath9k.h @@ -309,7 +309,6 @@ struct ath_rx { u8 rxotherant; u32 *rxlink; unsigned int rxfilter; - spinlock_t rxbuflock; struct list_head rxbuf; struct ath_descdma rxdma; struct ath_buf *rx_bufptr; diff --git a/drivers/net/wireless/ath/ath9k/recv.c b/drivers/net/wireless/ath/ath9k/recv.c index 039c220..0247fb1 100644 --- a/drivers/net/wireless/ath/ath9k/recv.c +++ b/drivers/net/wireless/ath/ath9k/recv.c @@ -291,8 +291,6 @@ rx_init_fail: static void ath_edma_start_recv(struct ath_softc *sc) { - spin_lock_bh(&sc->rx.rxbuflock); - ath9k_hw_rxena(sc->sc_ah); ath_rx_addbuffer_edma(sc, ATH9K_RX_QUEUE_HP, @@ -304,8 +302,6 @@ static void ath_edma_start_recv(struct ath_softc *sc) 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) @@ -322,7 +318,6 @@ int ath_rx_init(struct ath_softc *sc, int nbufs) int error = 0; spin_lock_init(&sc->sc_pcu_lock); - spin_lock_init(&sc->rx.rxbuflock); common->rx_bufsize = IEEE80211_MAX_MPDU_LEN / 2 + sc->sc_ah->caps.rx_status_len; @@ -480,7 +475,6 @@ int ath_startrecv(struct ath_softc *sc) return 0; } - spin_lock_bh(&sc->rx.rxbuflock); if (list_empty(&sc->rx.rxbuf)) goto start_recv; @@ -501,8 +495,6 @@ start_recv: ath_opmode_init(sc); ath9k_hw_startpcureceive(ah, (sc->sc_flags & SC_OP_OFFCHANNEL)); - spin_unlock_bh(&sc->rx.rxbuflock); - return 0; } @@ -518,7 +510,6 @@ bool ath_stoprecv(struct ath_softc *sc) struct ath_hw *ah = sc->sc_ah; bool stopped, reset = false; - spin_lock_bh(&sc->rx.rxbuflock); ath9k_hw_abortpcurecv(ah); ath9k_hw_setrxfilter(ah, 0); stopped = ath9k_hw_stopdmarecv(ah, &reset); @@ -529,7 +520,6 @@ bool ath_stoprecv(struct ath_softc *sc) ath_edma_stop_recv(sc); else sc->rx.rxlink = NULL; - spin_unlock_bh(&sc->rx.rxbuflock); if (!(ah->ah_flags & AH_UNPLUGGED) && unlikely(!stopped)) { @@ -1796,7 +1786,6 @@ int ath_rx_tasklet(struct ath_softc *sc, int flush, bool hp) dma_type = DMA_FROM_DEVICE; qtype = hp ? ATH9K_RX_QUEUE_HP : ATH9K_RX_QUEUE_LP; - spin_lock_bh(&sc->rx.rxbuflock); tsf = ath9k_hw_gettsf64(ah); tsf_lower = tsf & 0xffffffff; @@ -1988,8 +1977,6 @@ requeue: } } while (1); - spin_unlock_bh(&sc->rx.rxbuflock); - if (!(ah->imask & ATH9K_INT_RXEOL)) { ah->imask |= (ATH9K_INT_RXEOL | ATH9K_INT_RXORN); ath9k_hw_set_interrupts(ah); -- 1.7.9.5
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