From patchwork Tue Jan 31 13:53:24 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Francois Romieu X-Patchwork-Id: 138781 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 97C9EB71AD for ; Wed, 1 Feb 2012 01:04:55 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753558Ab2AaOEw (ORCPT ); Tue, 31 Jan 2012 09:04:52 -0500 Received: from violet.fr.zoreil.com ([92.243.8.30]:55975 "EHLO violet.fr.zoreil.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752717Ab2AaOEu (ORCPT ); Tue, 31 Jan 2012 09:04:50 -0500 Received: from violet.fr.zoreil.com (localhost [127.0.0.1]) by violet.fr.zoreil.com (8.13.8/8.13.8) with ESMTP id q0VDrVdj018142; Tue, 31 Jan 2012 14:53:33 +0100 Received: (from romieu@localhost) by violet.fr.zoreil.com (8.13.8/8.13.8/Submit) id q0VDrSan018141; Tue, 31 Jan 2012 14:53:29 +0100 Date: Tue, 31 Jan 2012 14:53:24 +0100 From: Francois Romieu To: davem@davemloft.net Cc: netdev@vger.kernel.org, Eric Dumazet , =?utf-8?B?TWljaGHFgiBNaXJvc8WCYXc=?= , Hayes Wang Subject: [PATCH net-next 0/5] Pull request for 'davem-next.r8169' branch Message-ID: <20120131135322.GA18106@electric-eye.fr.zoreil.com> Mime-Version: 1.0 Content-Disposition: inline User-Agent: Mutt/1.4.2.2i X-Organisation: Land of Sunshine Inc. Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Please pull from branch 'davem-next.r8169' in repository git://violet.fr.zoreil.com/romieu/linux davem-next.r8169 to get the changes below. Distance from 'davem-next' (aacafba8c2f4e9c9f3f38c60be83b65e69866723) --------------------------------------------------------------------- 6c05d25267ebb371c4311de6904f740342e82f7c 934714d088f35b81edafdce89397969baf77fb8a 6c4a70c5f286077e78b294b3f3a93dc45c40db89 98ddf986fca17840e46e070354b7e2cd2169da15 ae1f23fb433ac0aaff8aeaa5a7b14348e9aa8277 Diffstat -------- drivers/net/ethernet/realtek/r8169.c | 61 +++++++++++++++++---------------- 1 files changed, 31 insertions(+), 30 deletions(-) Shortlog -------- Francois Romieu (5): r8169: fix early queue wake-up. r8169: bh locking redux and task scheduling. r8169: move task enable boolean to bitfield. r8169: avoid a useless work scheduling. r8169: spinlock redux. Patch ----- diff --git a/drivers/net/ethernet/realtek/r8169.c b/drivers/net/ethernet/realtek/r8169.c index d039d39..7077422 100644 --- a/drivers/net/ethernet/realtek/r8169.c +++ b/drivers/net/ethernet/realtek/r8169.c @@ -668,6 +668,7 @@ struct rtl8169_counters { }; enum rtl_flag { + RTL_FLAG_TASK_ENABLED, RTL_FLAG_TASK_SLOW_PENDING, RTL_FLAG_TASK_RESET_PENDING, RTL_FLAG_TASK_PHY_PENDING, @@ -679,7 +680,6 @@ struct rtl8169_private { struct pci_dev *pci_dev; struct net_device *dev; struct napi_struct napi; - spinlock_t lock; u32 msg_enable; u16 txd_version; u16 mac_version; @@ -725,7 +725,6 @@ struct rtl8169_private { DECLARE_BITMAP(flags, RTL_FLAG_MAX); struct mutex mutex; struct work_struct work; - bool enabled; } wk; unsigned features; @@ -1723,9 +1722,7 @@ static void rtl8169_get_regs(struct net_device *dev, struct ethtool_regs *regs, regs->len = R8169_REGS_SIZE; rtl_lock_work(tp); - spin_lock_bh(&tp->lock); memcpy_fromio(p, tp->mmio_addr, regs->len); - spin_unlock_bh(&tp->lock); rtl_unlock_work(tp); } @@ -3273,17 +3270,8 @@ out_mod_timer: static void rtl_schedule_task(struct rtl8169_private *tp, enum rtl_flag flag) { - spin_lock(&tp->lock); if (!test_and_set_bit(flag, tp->wk.flags)) schedule_work(&tp->wk.work); - spin_unlock(&tp->lock); -} - -static void rtl_schedule_task_bh(struct rtl8169_private *tp, enum rtl_flag flag) -{ - local_bh_disable(); - rtl_schedule_task(tp, flag); - local_bh_enable(); } static void rtl8169_phy_timer(unsigned long __opaque) @@ -3291,7 +3279,7 @@ static void rtl8169_phy_timer(unsigned long __opaque) struct net_device *dev = (struct net_device *)__opaque; struct rtl8169_private *tp = netdev_priv(dev); - rtl_schedule_task_bh(tp, RTL_FLAG_TASK_PHY_PENDING); + rtl_schedule_task(tp, RTL_FLAG_TASK_PHY_PENDING); } #ifdef CONFIG_NET_POLL_CONTROLLER @@ -4160,7 +4148,6 @@ rtl8169_init_one(struct pci_dev *pdev, const struct pci_device_id *ent) tp->do_ioctl = rtl_xmii_ioctl; } - spin_lock_init(&tp->lock); mutex_init(&tp->wk.mutex); /* Get MAC address */ @@ -4361,7 +4348,7 @@ static int rtl8169_open(struct net_device *dev) rtl_lock_work(tp); - tp->wk.enabled = true; + set_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags); napi_enable(&tp->napi); @@ -5559,7 +5546,18 @@ static netdev_tx_t rtl8169_start_xmit(struct sk_buff *skb, mmiowb(); if (TX_BUFFS_AVAIL(tp) < MAX_SKB_FRAGS) { + /* Avoid wrongly optimistic queue wake-up: rtl_tx thread must + * not miss a ring update when it notices a stopped queue. + */ + smp_wmb(); netif_stop_queue(dev); + /* Sync with rtl_tx: + * - publish queue status and cur_tx ring index (write barrier) + * - refresh dirty_tx ring index (read barrier). + * May the current thread have a pessimistic view of the ring + * status and forget to wake up queue, a racing rtl_tx thread + * can't. + */ smp_mb(); if (TX_BUFFS_AVAIL(tp) >= MAX_SKB_FRAGS) netif_wake_queue(dev); @@ -5624,7 +5622,7 @@ static void rtl8169_pcierr_interrupt(struct net_device *dev) rtl8169_hw_reset(tp); - rtl_schedule_task_bh(tp, RTL_FLAG_TASK_RESET_PENDING); + rtl_schedule_task(tp, RTL_FLAG_TASK_RESET_PENDING); } static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp) @@ -5659,6 +5657,13 @@ static void rtl_tx(struct net_device *dev, struct rtl8169_private *tp) if (tp->dirty_tx != dirty_tx) { tp->dirty_tx = dirty_tx; + /* Sync with rtl8169_start_xmit: + * - publish dirty_tx ring index (write barrier) + * - refresh cur_tx ring index and queue status (read barrier) + * May the current thread miss the stopped queue condition, + * a racing xmit thread can only have a right view of the + * ring status. + */ smp_mb(); if (netif_queue_stopped(dev) && (TX_BUFFS_AVAIL(tp) >= MAX_SKB_FRAGS)) { @@ -5834,7 +5839,8 @@ static void rtl_slow_event_work(struct rtl8169_private *tp) /* Work around for rx fifo overflow */ case RTL_GIGA_MAC_VER_11: netif_stop_queue(dev); - rtl_schedule_task_bh(tp, RTL_FLAG_TASK_RESET_PENDING); + /* XXX - Hack alert. See rtl_task(). */ + set_bit(RTL_FLAG_TASK_RESET_PENDING, tp->wk.flags); default: break; } @@ -5859,6 +5865,7 @@ static void rtl_task(struct work_struct *work) int bitnr; void (*action)(struct rtl8169_private *); } rtl_work[] = { + /* XXX - keep rtl_slow_event_work() as first element. */ { RTL_FLAG_TASK_SLOW_PENDING, rtl_slow_event_work }, { RTL_FLAG_TASK_RESET_PENDING, rtl_reset_work }, { RTL_FLAG_TASK_PHY_PENDING, rtl_phy_work } @@ -5870,16 +5877,14 @@ static void rtl_task(struct work_struct *work) rtl_lock_work(tp); - if (!netif_running(dev) || !tp->wk.enabled) + if (!netif_running(dev) || + !test_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags)) goto out_unlock; for (i = 0; i < ARRAY_SIZE(rtl_work); i++) { bool pending; - spin_lock_bh(&tp->lock); pending = test_and_clear_bit(rtl_work[i].bitnr, tp->wk.flags); - spin_unlock_bh(&tp->lock); - if (pending) rtl_work[i].action(tp); } @@ -5971,7 +5976,7 @@ static int rtl8169_close(struct net_device *dev) rtl8169_update_counters(dev); rtl_lock_work(tp); - tp->wk.enabled = false; + clear_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags); rtl8169_down(dev); rtl_unlock_work(tp); @@ -6022,8 +6027,6 @@ static void rtl_set_rx_mode(struct net_device *dev) } } - spin_lock_bh(&tp->lock); - tmp = (RTL_R32(RxConfig) & ~RX_CONFIG_ACCEPT_MASK) | rx_mode; if (tp->mac_version > RTL_GIGA_MAC_VER_06) { @@ -6037,8 +6040,6 @@ static void rtl_set_rx_mode(struct net_device *dev) RTL_W32(MAR0 + 0, mc_filter[0]); RTL_W32(RxConfig, tmp); - - spin_unlock_bh(&tp->lock); } /** @@ -6070,7 +6071,7 @@ static void rtl8169_net_suspend(struct net_device *dev) rtl_lock_work(tp); napi_disable(&tp->napi); - tp->wk.enabled = false; + clear_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags); rtl_unlock_work(tp); rtl_pll_power_down(tp); @@ -6096,9 +6097,9 @@ static void __rtl8169_resume(struct net_device *dev) rtl_pll_power_up(tp); - tp->wk.enabled = true; + set_bit(RTL_FLAG_TASK_ENABLED, tp->wk.flags); - rtl_schedule_task_bh(tp, RTL_FLAG_TASK_RESET_PENDING); + rtl_schedule_task(tp, RTL_FLAG_TASK_RESET_PENDING); } static int rtl8169_resume(struct device *device)