net: hip04: Make tx coalesce timer actually work

The code sets the expiry value of the timer to a relative value and
starts it with hrtimer_start_expires. That's fine, but that only works
once. The timer is started in relative mode, so the expiry value gets
overwritten with the absolut expiry time (now + expiry).

So once the timer expired, a new call to hrtimer_start_expires results
in an immidiately expired timer, because the expiry value is
already in the past.

Use the proper mechanisms to (re)start the timer in the intended way.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: dingtianhong <dingtianhong@huawei.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: netdev@vger.kernel.org
Acked-by: Ding Tianhong <dingtianhong@huawei.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/hisilicon/hip04_eth.c b/drivers/net/ethernet/hisilicon/hip04_eth.c
index b72d238695d73584e7527c3b31fa70f6f3ab0113..3b39fdddeb57140c2d00003a0c473a869f768252 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hip04_eth.c
+++ b/drivers/net/ethernet/hisilicon/hip04_eth.c
@@ -413,6 +413,15 @@ out:
        return count;
 }
 
+static void hip04_start_tx_timer(struct hip04_priv *priv)
+{
+       unsigned long ns = priv->tx_coalesce_usecs * NSEC_PER_USEC / 2;
+
+       /* allow timer to fire after half the time at the earliest */
+       hrtimer_start_range_ns(&priv->tx_coalesce_timer, ns_to_ktime(ns),
+                              ns, HRTIMER_MODE_REL);
+}
+
 static int hip04_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 {
        struct hip04_priv *priv = netdev_priv(ndev);
@@ -466,8 +475,7 @@ static int hip04_mac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
                }
        } else if (!hrtimer_is_queued(&priv->tx_coalesce_timer)) {
                /* cleanup not pending yet, start a new timer */
-               hrtimer_start_expires(&priv->tx_coalesce_timer,
-                                     HRTIMER_MODE_REL);
+               hip04_start_tx_timer(priv);
        }
 
        return NETDEV_TX_OK;
@@ -549,7 +557,7 @@ done:
        /* clean up tx descriptors and start a new timer if necessary */
        tx_remaining = hip04_tx_reclaim(ndev, false);
        if (rx < budget && tx_remaining)
-               hrtimer_start_expires(&priv->tx_coalesce_timer, HRTIMER_MODE_REL);
+               hip04_start_tx_timer(priv);
 
        return rx;
 }
@@ -809,7 +817,6 @@ static int hip04_mac_probe(struct platform_device *pdev)
        struct hip04_priv *priv;
        struct resource *res;
        unsigned int irq;
-       ktime_t txtime;
        int ret;
 
        ndev = alloc_etherdev(sizeof(struct hip04_priv));
@@ -846,9 +853,6 @@ static int hip04_mac_probe(struct platform_device *pdev)
         */
        priv->tx_coalesce_frames = TX_DESC_NUM * 3 / 4;
        priv->tx_coalesce_usecs = 200;
-       /* allow timer to fire after half the time at the earliest */
-       txtime = ktime_set(0, priv->tx_coalesce_usecs * NSEC_PER_USEC / 2);
-       hrtimer_set_expires_range(&priv->tx_coalesce_timer, txtime, txtime);
        priv->tx_coalesce_timer.function = tx_done;
 
        priv->map = syscon_node_to_regmap(arg.np);