From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754661AbbDNTmo (ORCPT ); Tue, 14 Apr 2015 15:42:44 -0400 Received: from www.linutronix.de ([62.245.132.108]:37658 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752958AbbDNTmf (ORCPT ); Tue, 14 Apr 2015 15:42:35 -0400 Date: Tue, 14 Apr 2015 21:42:42 +0200 (CEST) From: Thomas Gleixner To: David Miller cc: arnd@arndb.de, linux-kernel@vger.kernel.org, peterz@infradead.org, mingo@kernel.org, dingtianhong@huawei.com, zhangfei.gao@linaro.org, dan.carpenter@oracle.com, netdev@vger.kernel.org Subject: [patch v2] net: hip04: Make tx coalesce timer actually work In-Reply-To: <20150414.141529.797692010779414843.davem@davemloft.net> Message-ID: References: <3040901.Bp3bfgc1te@wuerfel> <20150414.141529.797692010779414843.davem@davemloft.net> User-Agent: Alpine 2.11 (DEB 23 2013-08-11) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001,URIBL_BLOCKED=0.001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 Cc: "David S. Miller" Cc: dingtianhong Cc: Arnd Bergmann Cc: Zhangfei Gao Cc: Dan Carpenter 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);