[PATCH net-next 2/6] atl1c: remove private tx lock

From: Florian Westphal
Date: Sun Apr 24 2016 - 15:39:42 EST


AFAICS this is safe: the lock is only used in the .ndo_start_xmit
function and this driver does not set LLTX.

Gets rid of TX_LOCKED return value, followup patches will remove it.

Cc: Jay Cliburn <jcliburn@xxxxxxxxx>
Cc: Chris Snook <chris.snook@xxxxxxxxx>
Signed-off-by: Florian Westphal <fw@xxxxxxxxx>
---
drivers/net/ethernet/atheros/atl1c/atl1c.h | 3 +--
drivers/net/ethernet/atheros/atl1c/atl1c_main.c | 11 -----------
2 files changed, 1 insertion(+), 13 deletions(-)

diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c.h b/drivers/net/ethernet/atheros/atl1c/atl1c.h
index b9203d9..c46b489 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c.h
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c.h
@@ -488,7 +488,7 @@ struct atl1c_tpd_ring {
dma_addr_t dma; /* descriptor ring physical address */
u16 size; /* descriptor ring length in bytes */
u16 count; /* number of descriptors in the ring */
- u16 next_to_use; /* this is protectd by adapter->tx_lock */
+ u16 next_to_use;
atomic_t next_to_clean;
struct atl1c_buffer *buffer_info;
};
@@ -542,7 +542,6 @@ struct atl1c_adapter {
u16 link_duplex;

spinlock_t mdio_lock;
- spinlock_t tx_lock;
atomic_t irq_sem;

struct work_struct common_task;
diff --git a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
index d0084d4..a3200ea 100644
--- a/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
+++ b/drivers/net/ethernet/atheros/atl1c/atl1c_main.c
@@ -821,7 +821,6 @@ static int atl1c_sw_init(struct atl1c_adapter *adapter)
atl1c_set_rxbufsize(adapter, adapter->netdev);
atomic_set(&adapter->irq_sem, 1);
spin_lock_init(&adapter->mdio_lock);
- spin_lock_init(&adapter->tx_lock);
set_bit(__AT_DOWN, &adapter->flags);

return 0;
@@ -2206,7 +2205,6 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff *skb,
struct net_device *netdev)
{
struct atl1c_adapter *adapter = netdev_priv(netdev);
- unsigned long flags;
u16 tpd_req = 1;
struct atl1c_tpd_desc *tpd;
enum atl1c_trans_queue type = atl1c_trans_normal;
@@ -2217,16 +2215,10 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff *skb,
}

tpd_req = atl1c_cal_tpd_req(skb);
- if (!spin_trylock_irqsave(&adapter->tx_lock, flags)) {
- if (netif_msg_pktdata(adapter))
- dev_info(&adapter->pdev->dev, "tx locked\n");
- return NETDEV_TX_LOCKED;
- }

if (atl1c_tpd_avail(adapter, type) < tpd_req) {
/* no enough descriptor, just stop queue */
netif_stop_queue(netdev);
- spin_unlock_irqrestore(&adapter->tx_lock, flags);
return NETDEV_TX_BUSY;
}

@@ -2234,7 +2226,6 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff *skb,

/* do TSO and check sum */
if (atl1c_tso_csum(adapter, skb, &tpd, type) != 0) {
- spin_unlock_irqrestore(&adapter->tx_lock, flags);
dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}
@@ -2257,12 +2248,10 @@ static netdev_tx_t atl1c_xmit_frame(struct sk_buff *skb,
"tx-skb droppted due to dma error\n");
/* roll back tpd/buffer */
atl1c_tx_rollback(adapter, tpd, type);
- spin_unlock_irqrestore(&adapter->tx_lock, flags);
dev_kfree_skb_any(skb);
} else {
netdev_sent_queue(adapter->netdev, skb->len);
atl1c_tx_queue(adapter, skb, tpd, type);
- spin_unlock_irqrestore(&adapter->tx_lock, flags);
}

return NETDEV_TX_OK;
--
2.7.3