From 739c8e149ae40a1eb044edb92a133b93b59369d8 Mon Sep 17 00:00:00 2001 From: Lino Sanfilippo Date: Fri, 9 Dec 2016 00:55:43 +0100 Subject: [PATCH] net: ethernet: stmmac: remove private tx queue lock The driver uses a private lock for synchronization of the xmit function and the xmit completion handler, but since the NETIF_F_LLTX flag is not set, the xmit function is also called with the xmit_lock held. On the other hand the completion handler uses the reverse locking order by first taking the private lock and (in case that the tx queue had been stopped) then the xmit_lock. Improve the locking by removing the private lock and using only the xmit_lock for synchronization instead. Signed-off-by: Lino Sanfilippo Signed-off-by: David S. Miller --- drivers/net/ethernet/stmicro/stmmac/stmmac.h | 1 - drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 28 +++++------------------ 2 files changed, 6 insertions(+), 23 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h index dbacb80..eab04ae 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h @@ -64,7 +64,6 @@ struct stmmac_priv { dma_addr_t dma_tx_phy; int tx_coalesce; int hwts_tx_en; - spinlock_t tx_lock; bool tx_path_in_lpi_mode; struct timer_list txtimer; bool tso; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index b518812..3e40578 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -1308,7 +1308,7 @@ static void stmmac_tx_clean(struct stmmac_priv *priv) unsigned int bytes_compl = 0, pkts_compl = 0; unsigned int entry = priv->dirty_tx; - spin_lock(&priv->tx_lock); + netif_tx_lock(priv->dev); priv->xstats.tx_clean++; @@ -1379,22 +1379,17 @@ static void stmmac_tx_clean(struct stmmac_priv *priv) netdev_completed_queue(priv->dev, pkts_compl, bytes_compl); if (unlikely(netif_queue_stopped(priv->dev) && - stmmac_tx_avail(priv) > STMMAC_TX_THRESH)) { - netif_tx_lock(priv->dev); - if (netif_queue_stopped(priv->dev) && - stmmac_tx_avail(priv) > STMMAC_TX_THRESH) { - netif_dbg(priv, tx_done, priv->dev, - "%s: restart transmit\n", __func__); - netif_wake_queue(priv->dev); - } - netif_tx_unlock(priv->dev); + stmmac_tx_avail(priv) > STMMAC_TX_THRESH)) { + netif_dbg(priv, tx_done, priv->dev, + "%s: restart transmit\n", __func__); + netif_wake_queue(priv->dev); } if ((priv->eee_enabled) && (!priv->tx_path_in_lpi_mode)) { stmmac_enable_eee_mode(priv); mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(eee_timer)); } - spin_unlock(&priv->tx_lock); + netif_tx_unlock(priv->dev); } static inline void stmmac_enable_dma_irq(struct stmmac_priv *priv) @@ -2002,8 +1997,6 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev) u8 proto_hdr_len; int i; - spin_lock(&priv->tx_lock); - /* Compute header lengths */ proto_hdr_len = skb_transport_offset(skb) + tcp_hdrlen(skb); @@ -2017,7 +2010,6 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev) "%s: Tx Ring full when queue awake\n", __func__); } - spin_unlock(&priv->tx_lock); return NETDEV_TX_BUSY; } @@ -2152,11 +2144,9 @@ static netdev_tx_t stmmac_tso_xmit(struct sk_buff *skb, struct net_device *dev) priv->hw->dma->set_tx_tail_ptr(priv->ioaddr, priv->tx_tail_addr, STMMAC_CHAN0); - spin_unlock(&priv->tx_lock); return NETDEV_TX_OK; dma_map_err: - spin_unlock(&priv->tx_lock); dev_err(priv->device, "Tx dma map failed\n"); dev_kfree_skb(skb); priv->dev->stats.tx_dropped++; @@ -2188,10 +2178,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) return stmmac_tso_xmit(skb, dev); } - spin_lock(&priv->tx_lock); - if (unlikely(stmmac_tx_avail(priv) < nfrags + 1)) { - spin_unlock(&priv->tx_lock); if (!netif_queue_stopped(dev)) { netif_stop_queue(dev); /* This is a hard error, log it. */ @@ -2362,11 +2349,9 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) priv->hw->dma->set_tx_tail_ptr(priv->ioaddr, priv->tx_tail_addr, STMMAC_CHAN0); - spin_unlock(&priv->tx_lock); return NETDEV_TX_OK; dma_map_err: - spin_unlock(&priv->tx_lock); netdev_err(priv->dev, "Tx DMA map failed\n"); dev_kfree_skb(skb); priv->dev->stats.tx_dropped++; @@ -3353,7 +3338,6 @@ int stmmac_dvr_probe(struct device *device, netif_napi_add(ndev, &priv->napi, stmmac_poll, 64); spin_lock_init(&priv->lock); - spin_lock_init(&priv->tx_lock); ret = register_netdev(ndev); if (ret) { -- 2.7.4