[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.

1 files changed, 33 insertions, 54 deletions

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));