libertas: detect TX lockups and reset hardware
authorDaniel Drake <dsd@laptop.org>
Mon, 3 Oct 2011 10:33:02 +0000 (11:33 +0100)
committerJohn W. Linville <linville@tuxdriver.com>
Mon, 3 Oct 2011 19:22:41 +0000 (15:22 -0400)
Recent patches added support for resetting the SD8686 hardware when
commands time out, which seems to happen quite frequently soon after
resuming the system from a Wake-on-WLAN-triggered resume.

At http://dev.laptop.org/ticket/10969 we see the same thing happen
with transmits. In this case, the hardware will fail to respond to
a frame passed for transmission, and libertas (correctly) will block
all further commands and transmissions as the hardware can only
deal with one thing at a time. This results in a lockup while the
system waits indefinitely for the dead card to respond.

Hook up a TX lockup timer to detect this and reset the hardware.

Signed-off-by: Daniel Drake <dsd@laptop.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
drivers/net/wireless/libertas/dev.h
drivers/net/wireless/libertas/main.c

index fb3e40bf59025fa7bd189f1eae4c61b089d15a20..f3fd447131c2c9d20ffa84b52a5ffff20ee7f233 100644 (file)
@@ -158,6 +158,7 @@ struct lbs_private {
        /* protected by hard_start_xmit serialization */
        u8 txretrycount;
        struct sk_buff *currenttxskb;
+       struct timer_list tx_lockup_timer;
 
        /* Locks */
        struct mutex lock;
index d62d1fb4177f677c318d8040e7ba3542ee1e29f4..6a326233391fde7ec0b49e7943e7c64aa8bb4566 100644 (file)
@@ -188,6 +188,7 @@ int lbs_stop_iface(struct lbs_private *priv)
        spin_unlock_irqrestore(&priv->driver_lock, flags);
 
        cancel_work_sync(&priv->mcast_work);
+       del_timer_sync(&priv->tx_lockup_timer);
 
        /* Disable command processing, and wait for all commands to complete */
        lbs_deb_main("waiting for commands to complete\n");
@@ -243,6 +244,7 @@ void lbs_host_to_card_done(struct lbs_private *priv)
        lbs_deb_enter(LBS_DEB_THREAD);
 
        spin_lock_irqsave(&priv->driver_lock, flags);
+       del_timer(&priv->tx_lockup_timer);
 
        priv->dnld_sent = DNLD_RES_RECEIVED;
 
@@ -585,6 +587,9 @@ static int lbs_thread(void *data)
                        if (ret) {
                                lbs_deb_tx("host_to_card failed %d\n", ret);
                                priv->dnld_sent = DNLD_RES_RECEIVED;
+                       } else {
+                               mod_timer(&priv->tx_lockup_timer,
+                                         jiffies + (HZ * 5));
                        }
                        priv->tx_pending_len = 0;
                        if (!priv->currenttxskb) {
@@ -601,6 +606,7 @@ static int lbs_thread(void *data)
        }
 
        del_timer(&priv->command_timer);
+       del_timer(&priv->tx_lockup_timer);
        del_timer(&priv->auto_deepsleep_timer);
 
        lbs_deb_leave(LBS_DEB_THREAD);
@@ -734,6 +740,32 @@ out:
        lbs_deb_leave(LBS_DEB_CMD);
 }
 
+/**
+ * lbs_tx_lockup_handler - handles the timeout of the passing of TX frames
+ * to the hardware. This is known to frequently happen with SD8686 when
+ * waking up after a Wake-on-WLAN-triggered resume.
+ *
+ * @data: &struct lbs_private pointer
+ */
+static void lbs_tx_lockup_handler(unsigned long data)
+{
+       struct lbs_private *priv = (struct lbs_private *)data;
+       unsigned long flags;
+
+       lbs_deb_enter(LBS_DEB_TX);
+       spin_lock_irqsave(&priv->driver_lock, flags);
+
+       netdev_info(priv->dev, "TX lockup detected\n");
+       if (priv->reset_card)
+               priv->reset_card(priv);
+
+       priv->dnld_sent = DNLD_RES_RECEIVED;
+       wake_up_interruptible(&priv->waitq);
+
+       spin_unlock_irqrestore(&priv->driver_lock, flags);
+       lbs_deb_leave(LBS_DEB_TX);
+}
+
 /**
  * auto_deepsleep_timer_fn - put the device back to deep sleep mode when
  * timer expires and no activity (command, event, data etc.) is detected.
@@ -820,6 +852,8 @@ static int lbs_init_adapter(struct lbs_private *priv)
 
        setup_timer(&priv->command_timer, lbs_cmd_timeout_handler,
                (unsigned long)priv);
+       setup_timer(&priv->tx_lockup_timer, lbs_tx_lockup_handler,
+               (unsigned long)priv);
        setup_timer(&priv->auto_deepsleep_timer, auto_deepsleep_timer_fn,
                        (unsigned long)priv);
 
@@ -857,6 +891,7 @@ static void lbs_free_adapter(struct lbs_private *priv)
        lbs_free_cmd_buffer(priv);
        kfifo_free(&priv->event_fifo);
        del_timer(&priv->command_timer);
+       del_timer(&priv->tx_lockup_timer);
        del_timer(&priv->auto_deepsleep_timer);
 
        lbs_deb_leave(LBS_DEB_MAIN);