[PATCH 38/93] ath9k: remove sc->rx.rxbuflock to fix a deadlock
From: Herton Ronaldo Krzesinski
Date: Tue Feb 05 2013 - 17:24:55 EST
3.5.7.5 -stable review patch. If anyone has any objections, please let me know.
------------------
From: Felix Fietkau <nbd@xxxxxxxxxxx>
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@xxxxxxxxxxxxxxxx>
Signed-off-by: Felix Fietkau <nbd@xxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
[ herton: adjust context ]
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@xxxxxxxxxxxxx>
---
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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