lkml.org 
[lkml]   [2015]   [Apr]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [patch v2] net: hip04: Make tx coalesce timer actually work
On 2015/4/15 3:42, Thomas Gleixner wrote:
> 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.
>

Acked-by: Ding Tianhong <dingtianhong@huawei.com>

> 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
> ---
> drivers/net/ethernet/hisilicon/hip04_eth.c | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> Index: linux/drivers/net/ethernet/hisilicon/hip04_eth.c
> ===================================================================
> --- linux.orig/drivers/net/ethernet/hisilicon/hip04_eth.c
> +++ linux/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 s
> }
> } 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 platfo
> 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 platfo
> */
> 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);
>
> .
>




\
 
 \ /
  Last update: 2015-04-15 04:41    [W:0.104 / U:6.768 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site