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Commit ef71ff83 authored by Rajesh K Borundia's avatar Rajesh K Borundia Committed by David S. Miller
Browse files

qlcnic: fix race in tx stop queue 



There is a race between netif_stop_queue and netif_stopped_queue
check. So check once again if buffers are available to avoid race.
With above logic we can also get rid of tx lock in process_cmd_ring.

Signed-off-by: default avatarRajesh K Borundia <rajesh.borundia@qlogic.com>
Signed-off-by: default avatarAmit Kumar Salecha <amit.salecha@qlogic.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8f891387

drivers/net/qlcnic/qlcnic.h

+5 −3
Original line number Diff line number Diff line
@@ -113,8 +113,10 @@ 
#define TX_UDPV6_PKT	0x0c



/* Tx defines */

#define MAX_BUFFERS_PER_CMD	32

#define TX_STOP_THRESH		((MAX_SKB_FRAGS >> 2) + 4)

#define MAX_TSO_HEADER_DESC	2

#define MGMT_CMD_DESC_RESV	4

#define TX_STOP_THRESH		((MAX_SKB_FRAGS >> 2) + MAX_TSO_HEADER_DESC \

							+ MGMT_CMD_DESC_RESV)

#define QLCNIC_MAX_TX_TIMEOUTS	2



/*
@@ -369,7 +371,7 @@ struct qlcnic_recv_crb { 
 */

struct qlcnic_cmd_buffer {

	struct sk_buff *skb;

	struct qlcnic_skb_frag frag_array[MAX_BUFFERS_PER_CMD + 1];

	struct qlcnic_skb_frag frag_array[MAX_SKB_FRAGS + 1];

	u32 frag_count;

};

drivers/net/qlcnic/qlcnic_hw.c

+9 −3
Original line number Diff line number Diff line
@@ -338,10 +338,16 @@ qlcnic_send_cmd_descs(struct qlcnic_adapter *adapter, 


	if (nr_desc >= qlcnic_tx_avail(tx_ring)) {

		netif_tx_stop_queue(tx_ring->txq);

		__netif_tx_unlock_bh(tx_ring->txq);

		smp_mb();

		if (qlcnic_tx_avail(tx_ring) > nr_desc) {

			if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH)

				netif_tx_wake_queue(tx_ring->txq);

		} else {

			adapter->stats.xmit_off++;

			__netif_tx_unlock_bh(tx_ring->txq);

			return -EBUSY;

		}

	}



	do {

		cmd_desc = &cmd_desc_arr[i];

drivers/net/qlcnic/qlcnic_init.c

+2 −0
Original line number Diff line number Diff line
@@ -181,7 +181,9 @@ void qlcnic_free_sw_resources(struct qlcnic_adapter *adapter) 


	tx_ring = adapter->tx_ring;

	vfree(tx_ring->cmd_buf_arr);

	tx_ring->cmd_buf_arr = NULL;

	kfree(adapter->tx_ring);

	adapter->tx_ring = NULL;

}



int qlcnic_alloc_sw_resources(struct qlcnic_adapter *adapter)

drivers/net/qlcnic/qlcnic_main.c

+10 −13
Original line number Diff line number Diff line
@@ -132,12 +132,6 @@ qlcnic_update_cmd_producer(struct qlcnic_adapter *adapter, 
		struct qlcnic_host_tx_ring *tx_ring)

{

	writel(tx_ring->producer, tx_ring->crb_cmd_producer);



	if (qlcnic_tx_avail(tx_ring) <= TX_STOP_THRESH) {

		netif_stop_queue(adapter->netdev);

		smp_mb();

		adapter->stats.xmit_off++;

	}

}



static const u32 msi_tgt_status[8] = {
@@ -1137,7 +1131,7 @@ qlcnic_setup_netdev(struct qlcnic_adapter *adapter, 
	adapter->max_mc_count = 38;



	netdev->netdev_ops	   = &qlcnic_netdev_ops;

	netdev->watchdog_timeo     = 2*HZ;

	netdev->watchdog_timeo     = 5*HZ;



	qlcnic_change_mtu(netdev, netdev->mtu);
@@ -1709,11 +1703,16 @@ qlcnic_xmit_frame(struct sk_buff *skb, struct net_device *netdev) 
	/* 4 fragments per cmd des */

	no_of_desc = (frag_count + 3) >> 2;



	if (unlikely(no_of_desc + 2 > qlcnic_tx_avail(tx_ring))) {

	if (unlikely(qlcnic_tx_avail(tx_ring) <= TX_STOP_THRESH)) {

		netif_stop_queue(netdev);

		smp_mb();

		if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH)

			netif_start_queue(netdev);

		else {

			adapter->stats.xmit_off++;

			return NETDEV_TX_BUSY;

		}

	}



	producer = tx_ring->producer;

	pbuf = &tx_ring->cmd_buf_arr[producer];
@@ -2018,14 +2017,12 @@ static int qlcnic_process_cmd_ring(struct qlcnic_adapter *adapter) 
		smp_mb();



		if (netif_queue_stopped(netdev) && netif_carrier_ok(netdev)) {

			__netif_tx_lock(tx_ring->txq, smp_processor_id());

			if (qlcnic_tx_avail(tx_ring) > TX_STOP_THRESH) {

				netif_wake_queue(netdev);

				adapter->tx_timeo_cnt = 0;

				adapter->stats.xmit_on++;

			}

			__netif_tx_unlock(tx_ring->txq);

		}

		adapter->tx_timeo_cnt = 0;

	}

	/*

	 * If everything is freed up to consumer then check if the ring is full