p54spi: Fix workqueue deadlock

commit 2d1618170eb493d18f66f2ac03775409a6fb97c6 upstream.

priv->work must not be synced while priv->mutex is locked, because
the mutex is taken in the work handler.
Move cancel_work_sync down to after the device shutdown code.
This is safe, because the work handler checks fw_state and bails out
early in case of a race.

Signed-off-by: Michael Buesch <m@bues.ch>
Acked-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/net/wireless/p54/p54spi.c b/drivers/net/wireless/p54/p54spi.c
index b2f750a1e808cf0822f2a4b5c29c3d59d3de4446..d9bd46d49276cc4d8eac38c233eb75d758d2b543 100644 (file)
--- a/drivers/net/wireless/p54/p54spi.c
+++ b/drivers/net/wireless/p54/p54spi.c
@@ -581,8 +581,6 @@ static void p54spi_op_stop(struct ieee80211_hw *dev)
 
        WARN_ON(priv->fw_state != FW_STATE_READY);
 
-       cancel_work_sync(&priv->work);
-
        p54spi_power_off(priv);
        spin_lock_irqsave(&priv->tx_lock, flags);
        INIT_LIST_HEAD(&priv->tx_pending);
@@ -590,6 +588,8 @@ static void p54spi_op_stop(struct ieee80211_hw *dev)
 
        priv->fw_state = FW_STATE_OFF;
        mutex_unlock(&priv->mutex);
+
+       cancel_work_sync(&priv->work);
 }
 
 static int __devinit p54spi_probe(struct spi_device *spi)