[patch 17/45] ath5k: use spin_lock_irqsave for beacon lock

From: Chris Wright
Date: Tue Mar 31 2009 - 19:30:38 EST


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

From: Bob Copeland <me@xxxxxxxxxxxxxxx>

upstream commit: b5f03956c56d72ad336e5c2c42a025f25d952c30

ath5k_reset can be called from process context, which in turn can
call ath5k_beacon_config which takes the sc->block spinlock. Since
it can also be taken in hard irq context, use spin_lock_irqsave
everywhere. This fixes a potential deadlock in adhoc mode.

Changes-licensed-under: 3-Clause-BSD

Cc: stable@xxxxxxxxxx
Signed-off-by: Bob Copeland <me@xxxxxxxxxxxxxxx>
Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
---
drivers/net/wireless/ath5k/base.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/net/wireless/ath5k/base.c
+++ b/drivers/net/wireless/ath5k/base.c
@@ -1668,7 +1668,6 @@ ath5k_check_ibss_tsf(struct ath5k_softc
}
}

-
static void
ath5k_tasklet_rx(unsigned long data)
{
@@ -2188,6 +2187,7 @@ static void
ath5k_beacon_config(struct ath5k_softc *sc)
{
struct ath5k_hw *ah = sc->ah;
+ unsigned long flags;

ath5k_hw_set_imr(ah, 0);
sc->bmisscount = 0;
@@ -2211,9 +2211,9 @@ ath5k_beacon_config(struct ath5k_softc *

if (sc->opmode == NL80211_IFTYPE_ADHOC) {
if (ath5k_hw_hasveol(ah)) {
- spin_lock(&sc->block);
+ spin_lock_irqsave(&sc->block, flags);
ath5k_beacon_send(sc);
- spin_unlock(&sc->block);
+ spin_unlock_irqrestore(&sc->block, flags);
}
} else
ath5k_beacon_update_timers(sc, -1);

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