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Commit 0c235113 authored by Martin Habets's avatar Martin Habets Committed by David S. Miller
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sfc: stop the TX queue before pushing new buffers 



efx_enqueue_skb() can push new buffers for the xmit_more functionality.
We must stops the TX queue before this or else the TX queue does not get
restarted and we get a netdev watchdog.

In the error handling we may now need to unwind more than 1 packet, and
we may need to push the new buffers onto the partner queue.

v2: In the error leg also push this queue if xmit_more is set

Fixes: e9117e50 ("sfc: Firmware-Assisted TSO version 2")
Reported-by: default avatarJarod Wilson <jarod@redhat.com>
Tested-by: default avatarJarod Wilson <jarod@redhat.com>
Signed-off-by: default avatarMartin Habets <mhabets@solarflare.com>
Acked-by: default avatarEdward Cree <ecree@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7d850abd

drivers/net/ethernet/sfc/tx.c

+25 −8
Original line number Diff line number Diff line
@@ -435,17 +435,18 @@ static int efx_tx_map_data(struct efx_tx_queue *tx_queue, struct sk_buff *skb, 
	} while (1);

}



/* Remove buffers put into a tx_queue.  None of the buffers must have

 * an skb attached.

/* Remove buffers put into a tx_queue for the current packet.

 * None of the buffers must have an skb attached.

 */

static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue)

static void efx_enqueue_unwind(struct efx_tx_queue *tx_queue,

			       unsigned int insert_count)

{

	struct efx_tx_buffer *buffer;

	unsigned int bytes_compl = 0;

	unsigned int pkts_compl = 0;



	/* Work backwards until we hit the original insert pointer value */

	while (tx_queue->insert_count != tx_queue->write_count) {

	while (tx_queue->insert_count != insert_count) {

		--tx_queue->insert_count;

		buffer = __efx_tx_queue_get_insert_buffer(tx_queue);

		efx_dequeue_buffer(tx_queue, buffer, &pkts_compl, &bytes_compl);
@@ -504,6 +505,8 @@ static int efx_tx_tso_fallback(struct efx_tx_queue *tx_queue, 
 */

netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb)

{

	unsigned int old_insert_count = tx_queue->insert_count;

	bool xmit_more = skb->xmit_more;

	bool data_mapped = false;

	unsigned int segments;

	unsigned int skb_len;
@@ -553,8 +556,10 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) 
	/* Update BQL */

	netdev_tx_sent_queue(tx_queue->core_txq, skb_len);



	efx_tx_maybe_stop_queue(tx_queue);



	/* Pass off to hardware */

	if (!skb->xmit_more || netif_xmit_stopped(tx_queue->core_txq)) {

	if (!xmit_more || netif_xmit_stopped(tx_queue->core_txq)) {

		struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);



		/* There could be packets left on the partner queue if those
@@ -577,14 +582,26 @@ netdev_tx_t efx_enqueue_skb(struct efx_tx_queue *tx_queue, struct sk_buff *skb) 
		tx_queue->tx_packets++;

	}



	efx_tx_maybe_stop_queue(tx_queue);



	return NETDEV_TX_OK;





err:

	efx_enqueue_unwind(tx_queue);

	efx_enqueue_unwind(tx_queue, old_insert_count);

	dev_kfree_skb_any(skb);



	/* If we're not expecting another transmit and we had something to push

	 * on this queue or a partner queue then we need to push here to get the

	 * previous packets out.

	 */

	if (!xmit_more) {

		struct efx_tx_queue *txq2 = efx_tx_queue_partner(tx_queue);



		if (txq2->xmit_more_available)

			efx_nic_push_buffers(txq2);



		efx_nic_push_buffers(tx_queue);

	}



	return NETDEV_TX_OK;

}