From a15e0384dd22ee08f56d62761ce9d770488f6f4e Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Mon, 31 Oct 2005 07:59:37 -0500 Subject: [netdrvr 8139too] replace hand-crafted kernel thread with workqueue Gone are the days when 8139too was a shining example of how to use kernel threads. Delayed workqueues are easier, and map precisely to our task: running code from a kernel thread, after a periodic sleep. --- drivers/net/8139too.c | 87 +++++++++++++++++++-------------------------------- 1 file changed, 33 insertions(+), 54 deletions(-) (limited to 'drivers') diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c index 30bee11c48bd..9de58e249bc3 100644 --- a/drivers/net/8139too.c +++ b/drivers/net/8139too.c @@ -590,12 +590,12 @@ struct rtl8139_private { spinlock_t lock; spinlock_t rx_lock; chip_t chipset; - pid_t thr_pid; - wait_queue_head_t thr_wait; - struct completion thr_exited; u32 rx_config; struct rtl_extra_stats xstats; - int time_to_die; + + struct work_struct thread; + long time_to_die; /* -1 no thr, 0 thr active, 1 thr cancel */ + struct mii_if_info mii; unsigned int regs_len; unsigned long fifo_copy_timeout; @@ -620,7 +620,7 @@ static int rtl8139_open (struct net_device *dev); static int mdio_read (struct net_device *dev, int phy_id, int location); static void mdio_write (struct net_device *dev, int phy_id, int location, int val); -static void rtl8139_start_thread(struct net_device *dev); +static void rtl8139_start_thread(struct rtl8139_private *tp); static void rtl8139_tx_timeout (struct net_device *dev); static void rtl8139_init_ring (struct net_device *dev); static int rtl8139_start_xmit (struct sk_buff *skb, @@ -637,6 +637,7 @@ static struct net_device_stats *rtl8139_get_stats (struct net_device *dev); static void rtl8139_set_rx_mode (struct net_device *dev); static void __set_rx_mode (struct net_device *dev); static void rtl8139_hw_start (struct net_device *dev); +static void rtl8139_thread (void *_data); static struct ethtool_ops rtl8139_ethtool_ops; /* write MMIO register, with flush */ @@ -1007,8 +1008,7 @@ static int __devinit rtl8139_init_one (struct pci_dev *pdev, (debug < 0 ? RTL8139_DEF_MSG_ENABLE : ((1 << debug) - 1)); spin_lock_init (&tp->lock); spin_lock_init (&tp->rx_lock); - init_waitqueue_head (&tp->thr_wait); - init_completion (&tp->thr_exited); + INIT_WORK(&tp->thread, rtl8139_thread, dev); tp->mii.dev = dev; tp->mii.mdio_read = mdio_read; tp->mii.mdio_write = mdio_write; @@ -1345,7 +1345,7 @@ static int rtl8139_open (struct net_device *dev) dev->irq, RTL_R8 (MediaStatus), tp->mii.full_duplex ? "full" : "half"); - rtl8139_start_thread(dev); + rtl8139_start_thread(tp); return 0; } @@ -1594,56 +1594,45 @@ static inline void rtl8139_thread_iter (struct net_device *dev, RTL_R8 (Config1)); } -static int rtl8139_thread (void *data) +static void rtl8139_thread (void *_data) { - struct net_device *dev = data; + struct net_device *dev = _data; struct rtl8139_private *tp = netdev_priv(dev); - unsigned long timeout; - - daemonize("%s", dev->name); - allow_signal(SIGTERM); - - while (1) { - timeout = next_tick; - do { - timeout = interruptible_sleep_on_timeout (&tp->thr_wait, timeout); - /* make swsusp happy with our thread */ - try_to_freeze(); - } while (!signal_pending (current) && (timeout > 0)); - if (signal_pending (current)) { - flush_signals(current); - } - - if (tp->time_to_die) - break; - - if (rtnl_lock_interruptible ()) - break; + if ((tp->time_to_die == 0) && + (rtnl_lock_interruptible() == 0)) { rtl8139_thread_iter (dev, tp, tp->mmio_addr); rtnl_unlock (); } - complete_and_exit (&tp->thr_exited, 0); + if (tp->time_to_die == 0) + schedule_delayed_work(&tp->thread, next_tick); } -static void rtl8139_start_thread(struct net_device *dev) +static void rtl8139_start_thread(struct rtl8139_private *tp) { - struct rtl8139_private *tp = netdev_priv(dev); - - tp->thr_pid = -1; tp->twistie = 0; - tp->time_to_die = 0; + tp->time_to_die = -1; if (tp->chipset == CH_8139_K) tp->twistie = 1; else if (tp->drv_flags & HAS_LNK_CHNG) return; - tp->thr_pid = kernel_thread(rtl8139_thread, dev, CLONE_FS|CLONE_FILES); - if (tp->thr_pid < 0) { - printk (KERN_WARNING "%s: unable to start kernel thread\n", - dev->name); - } + tp->time_to_die = 0; + + schedule_delayed_work(&tp->thread, next_tick); +} + +static void rtl8139_stop_thread(struct rtl8139_private *tp) +{ + if (tp->time_to_die < 0) + return; + + tp->time_to_die = 1; + wmb(); + + if (cancel_delayed_work(&tp->thread) == 0) + flush_scheduled_work(); } static inline void rtl8139_tx_clear (struct rtl8139_private *tp) @@ -2224,22 +2213,12 @@ static int rtl8139_close (struct net_device *dev) { struct rtl8139_private *tp = netdev_priv(dev); void __iomem *ioaddr = tp->mmio_addr; - int ret = 0; unsigned long flags; netif_stop_queue (dev); - if (tp->thr_pid >= 0) { - tp->time_to_die = 1; - wmb(); - ret = kill_proc (tp->thr_pid, SIGTERM, 1); - if (ret) { - printk (KERN_ERR "%s: unable to signal thread\n", dev->name); - return ret; - } - wait_for_completion (&tp->thr_exited); - } - + rtl8139_stop_thread(tp); + if (netif_msg_ifdown(tp)) printk(KERN_DEBUG "%s: Shutting down ethercard, status was 0x%4.4x.\n", dev->name, RTL_R16 (IntrStatus)); -- cgit v1.2.3 From 38b492a21ac1b0f0a5ebed69c9e2ee6f4202f574 Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Fri, 4 Nov 2005 22:36:28 -0500 Subject: [netdrvr 8139too] use cancel_rearming_delayed_work() to cancel thread Noted by Herbert Xu. --- drivers/net/8139too.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) (limited to 'drivers') diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c index 9de58e249bc3..bcea9d41c32c 100644 --- a/drivers/net/8139too.c +++ b/drivers/net/8139too.c @@ -586,7 +586,8 @@ struct rtl8139_private { dma_addr_t tx_bufs_dma; signed char phys[4]; /* MII device addresses. */ char twistie, twist_row, twist_col; /* Twister tune state. */ - unsigned int default_port:4; /* Last dev->if_port value. */ + unsigned int default_port : 4; /* Last dev->if_port value. */ + unsigned int have_thread : 1; spinlock_t lock; spinlock_t rx_lock; chip_t chipset; @@ -594,7 +595,6 @@ struct rtl8139_private { struct rtl_extra_stats xstats; struct work_struct thread; - long time_to_die; /* -1 no thr, 0 thr active, 1 thr cancel */ struct mii_if_info mii; unsigned int regs_len; @@ -1599,40 +1599,33 @@ static void rtl8139_thread (void *_data) struct net_device *dev = _data; struct rtl8139_private *tp = netdev_priv(dev); - if ((tp->time_to_die == 0) && - (rtnl_lock_interruptible() == 0)) { + if (rtnl_lock_interruptible() == 0) { rtl8139_thread_iter (dev, tp, tp->mmio_addr); rtnl_unlock (); } - if (tp->time_to_die == 0) - schedule_delayed_work(&tp->thread, next_tick); + schedule_delayed_work(&tp->thread, next_tick); } static void rtl8139_start_thread(struct rtl8139_private *tp) { tp->twistie = 0; - tp->time_to_die = -1; if (tp->chipset == CH_8139_K) tp->twistie = 1; else if (tp->drv_flags & HAS_LNK_CHNG) return; - tp->time_to_die = 0; + tp->have_thread = 1; schedule_delayed_work(&tp->thread, next_tick); } static void rtl8139_stop_thread(struct rtl8139_private *tp) { - if (tp->time_to_die < 0) - return; - - tp->time_to_die = 1; - wmb(); - - if (cancel_delayed_work(&tp->thread) == 0) - flush_scheduled_work(); + if (tp->have_thread) { + cancel_rearming_delayed_work(&tp->thread); + tp->have_thread = 0; + } } static inline void rtl8139_tx_clear (struct rtl8139_private *tp) -- cgit v1.2.3 From 96a71d52bb91d9b386a60f904956420f98946dd3 Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Fri, 4 Nov 2005 22:46:35 -0500 Subject: [netdrvr 8139too] use rtnl_shlock_nowait() rather than rtnl_lock_interruptible() --- drivers/net/8139too.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c index bcea9d41c32c..120baaa90754 100644 --- a/drivers/net/8139too.c +++ b/drivers/net/8139too.c @@ -1599,7 +1599,7 @@ static void rtl8139_thread (void *_data) struct net_device *dev = _data; struct rtl8139_private *tp = netdev_priv(dev); - if (rtnl_lock_interruptible() == 0) { + if (rtnl_shlock_nowait() == 0) { rtl8139_thread_iter (dev, tp, tp->mmio_addr); rtnl_unlock (); } -- cgit v1.2.3 From 760559e1330a58cc5b320154a20e64b8444143c0 Mon Sep 17 00:00:00 2001 From: Jeff Garzik Date: Thu, 10 Nov 2005 04:31:55 -0500 Subject: [netdrvr 8139too] fast poll for thread, if an unlikely race occurs The rtl8139 thread is triggered only on rare 8139 hardware, the race itself is unlikely, and the impact of racing is low. We don't care enough to create a more-complex race-free solution. Rather, if the trylock fails, we now simply poll twice a second until we do get the lock. --- drivers/net/8139too.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/net/8139too.c b/drivers/net/8139too.c index 120baaa90754..d2102a27d307 100644 --- a/drivers/net/8139too.c +++ b/drivers/net/8139too.c @@ -1598,13 +1598,19 @@ static void rtl8139_thread (void *_data) { struct net_device *dev = _data; struct rtl8139_private *tp = netdev_priv(dev); + unsigned long thr_delay; if (rtnl_shlock_nowait() == 0) { rtl8139_thread_iter (dev, tp, tp->mmio_addr); rtnl_unlock (); + + thr_delay = next_tick; + } else { + /* unlikely race. mitigate with fast poll. */ + thr_delay = HZ / 2; } - schedule_delayed_work(&tp->thread, next_tick); + schedule_delayed_work(&tp->thread, thr_delay); } static void rtl8139_start_thread(struct rtl8139_private *tp) -- cgit v1.2.3