mac802154: tx: fix synced xmit deadlock (c3838353) · Commits · 戴 / test

This patch reverts ("mac802154: tx: don't allow if down while sync tx"). This has side effects with stop callback which flush the transmit workqueue. The stop callback will wait until the workqueue is flushed and holding the rtnl lock. That means it can happen that the stop callback waits forever because it try to lock the rtnl mutex which is already hold by stop callback. Cc: Michael Hennerich <michael.hennerich@analog.com> Signed-off-by:

Alexander Aring <alex.aring@gmail.com> Signed-off-by:

Marcel Holtmann <marcel@holtmann.org>

net/mac802154/driver-ops.h

+0 −3

Original line number	Diff line number	Diff line
		@@ -18,9 +18,6 @@ drv_xmit_async(struct ieee802154_local local, struct sk_buff skb)
		static inline int
		drv_xmit_sync(struct ieee802154_local local, struct sk_buff skb)
		{
		/* don't allow other operations while sync xmit */
		ASSERT_RTNL();

		might_sleep();

		return local->ops->xmit_sync(&local->hw, skb);

net/mac802154/tx.c

+0 −9

Original line number	Diff line number	Diff line
		@@ -38,12 +38,6 @@ void ieee802154_xmit_worker(struct work_struct *work)
		struct net_device *dev = skb->dev;
		int res;

		rtnl_lock();

		/* check if ifdown occurred while schedule */
		if (!netif_running(dev))
		goto err_tx;

		res = drv_xmit_sync(local, skb);
		if (res)
		goto err_tx;
		@@ -53,14 +47,11 @@ void ieee802154_xmit_worker(struct work_struct *work)
		dev->stats.tx_packets++;
		dev->stats.tx_bytes += skb->len;

		rtnl_unlock();

		return;

		err_tx:
		/* Restart the netif queue on each sub_if_data object. */
		ieee802154_wake_queue(&local->hw);
		rtnl_unlock();
		kfree_skb(skb);
		netdev_dbg(dev, "transmission failed\n");
		}

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