usbnet & cdc-ether: Autosuspend for online devices

Using remote wakeup and delayed transmission to allow
online device to go into usb autosuspend.
Minimal alternate support for devices that don't support
remote wakeup.

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 197912d..21e183a 100644 (file)
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -411,6 +411,12 @@ static int cdc_bind(struct usbnet *dev, struct usb_interface *intf)
        return 0;
 }
 
+static int cdc_manage_power(struct usbnet *dev, int on)
+{
+       dev->intf->needs_remote_wakeup = on;
+       return 0;
+}
+
 static const struct driver_info        cdc_info = {
        .description =  "CDC Ethernet Device",
        .flags =        FLAG_ETHER | FLAG_LINK_INTR,
@@ -418,6 +424,7 @@ static const struct driver_info     cdc_info = {
        .bind =         cdc_bind,
        .unbind =       usbnet_cdc_unbind,
        .status =       cdc_status,
+       .manage_power = cdc_manage_power,
 };
 
 static const struct driver_info mbm_info = {
@@ -619,6 +626,7 @@ static struct usb_driver cdc_driver = {
        .suspend =      usbnet_suspend,
        .resume =       usbnet_resume,
        .reset_resume = usbnet_resume,
+       .supports_autosuspend = 1,
 };
 
 

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 511e7bd..035fab0 100644 (file)
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -353,7 +353,8 @@ static void rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags)
 
        if (netif_running (dev->net) &&
            netif_device_present (dev->net) &&
-           !test_bit (EVENT_RX_HALT, &dev->flags)) {
+           !test_bit (EVENT_RX_HALT, &dev->flags) &&
+           !test_bit (EVENT_DEV_ASLEEP, &dev->flags)) {
                switch (retval = usb_submit_urb (urb, GFP_ATOMIC)) {
                case -EPIPE:
                        usbnet_defer_kevent (dev, EVENT_RX_HALT);
@@ -611,15 +612,39 @@ EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
 /*-------------------------------------------------------------------------*/
 
 // precondition: never called in_interrupt
+static void usbnet_terminate_urbs(struct usbnet *dev)
+{
+       DECLARE_WAIT_QUEUE_HEAD_ONSTACK(unlink_wakeup);
+       DECLARE_WAITQUEUE(wait, current);
+       int temp;
+
+       /* ensure there are no more active urbs */
+       add_wait_queue(&unlink_wakeup, &wait);
+       set_current_state(TASK_UNINTERRUPTIBLE);
+       dev->wait = &unlink_wakeup;
+       temp = unlink_urbs(dev, &dev->txq) +
+               unlink_urbs(dev, &dev->rxq);
+
+       /* maybe wait for deletions to finish. */
+       while (!skb_queue_empty(&dev->rxq)
+               && !skb_queue_empty(&dev->txq)
+               && !skb_queue_empty(&dev->done)) {
+                       schedule_timeout(UNLINK_TIMEOUT_MS);
+                       set_current_state(TASK_UNINTERRUPTIBLE);
+                       if (netif_msg_ifdown(dev))
+                               devdbg(dev, "waited for %d urb completions",
+                                       temp);
+       }
+       set_current_state(TASK_RUNNING);
+       dev->wait = NULL;
+       remove_wait_queue(&unlink_wakeup, &wait);
+}
 
 int usbnet_stop (struct net_device *net)
 {
        struct usbnet           *dev = netdev_priv(net);
        struct driver_info      *info = dev->driver_info;
-       int                     temp;
        int                     retval;
-       DECLARE_WAIT_QUEUE_HEAD_ONSTACK (unlink_wakeup);
-       DECLARE_WAITQUEUE (wait, current);
 
        netif_stop_queue (net);
 
@@ -641,25 +666,8 @@ int usbnet_stop (struct net_device *net)
                                info->description);
        }
 
-       if (!(info->flags & FLAG_AVOID_UNLINK_URBS)) {
-               /* ensure there are no more active urbs */
-               add_wait_queue(&unlink_wakeup, &wait);
-               dev->wait = &unlink_wakeup;
-               temp = unlink_urbs(dev, &dev->txq) +
-                       unlink_urbs(dev, &dev->rxq);
-
-               /* maybe wait for deletions to finish. */
-               while (!skb_queue_empty(&dev->rxq) &&
-                      !skb_queue_empty(&dev->txq) &&
-                      !skb_queue_empty(&dev->done)) {
-                       msleep(UNLINK_TIMEOUT_MS);
-                       if (netif_msg_ifdown(dev))
-                               devdbg(dev, "waited for %d urb completions",
-                                       temp);
-               }
-               dev->wait = NULL;
-               remove_wait_queue(&unlink_wakeup, &wait);
-       }
+       if (!(info->flags & FLAG_AVOID_UNLINK_URBS))
+               usbnet_terminate_urbs(dev);
 
        usb_kill_urb(dev->interrupt);
 
@@ -672,7 +680,10 @@ int usbnet_stop (struct net_device *net)
        dev->flags = 0;
        del_timer_sync (&dev->delay);
        tasklet_kill (&dev->bh);
-       usb_autopm_put_interface(dev->intf);
+       if (info->manage_power)
+               info->manage_power(dev, 0);
+       else
+               usb_autopm_put_interface(dev->intf);
 
        return 0;
 }
@@ -753,6 +764,12 @@ int usbnet_open (struct net_device *net)
 
        // delay posting reads until we're fully open
        tasklet_schedule (&dev->bh);
+       if (info->manage_power) {
+               retval = info->manage_power(dev, 1);
+               if (retval < 0)
+                       goto done;
+               usb_autopm_put_interface(dev->intf);
+       }
        return retval;
 done:
        usb_autopm_put_interface(dev->intf);
@@ -881,11 +898,16 @@ kevent (struct work_struct *work)
        /* usb_clear_halt() needs a thread context */
        if (test_bit (EVENT_TX_HALT, &dev->flags)) {
                unlink_urbs (dev, &dev->txq);
+               status = usb_autopm_get_interface(dev->intf);
+               if (status < 0)
+                       goto fail_pipe;
                status = usb_clear_halt (dev->udev, dev->out);
+               usb_autopm_put_interface(dev->intf);
                if (status < 0 &&
                    status != -EPIPE &&
                    status != -ESHUTDOWN) {
                        if (netif_msg_tx_err (dev))
+fail_pipe:
                                deverr (dev, "can't clear tx halt, status %d",
                                        status);
                } else {
@@ -896,11 +918,16 @@ kevent (struct work_struct *work)
        }
        if (test_bit (EVENT_RX_HALT, &dev->flags)) {
                unlink_urbs (dev, &dev->rxq);
+               status = usb_autopm_get_interface(dev->intf);
+               if (status < 0)
+                       goto fail_halt;
                status = usb_clear_halt (dev->udev, dev->in);
+               usb_autopm_put_interface(dev->intf);
                if (status < 0 &&
                    status != -EPIPE &&
                    status != -ESHUTDOWN) {
                        if (netif_msg_rx_err (dev))
+fail_halt:
                                deverr (dev, "can't clear rx halt, status %d",
                                        status);
                } else {
@@ -919,7 +946,12 @@ kevent (struct work_struct *work)
                        clear_bit (EVENT_RX_MEMORY, &dev->flags);
                if (urb != NULL) {
                        clear_bit (EVENT_RX_MEMORY, &dev->flags);
+                       status = usb_autopm_get_interface(dev->intf);
+                       if (status < 0)
+                               goto fail_lowmem;
                        rx_submit (dev, urb, GFP_KERNEL);
+                       usb_autopm_put_interface(dev->intf);
+fail_lowmem:
                        tasklet_schedule (&dev->bh);
                }
        }
@@ -929,11 +961,18 @@ kevent (struct work_struct *work)
                int                     retval = 0;
 
                clear_bit (EVENT_LINK_RESET, &dev->flags);
+               status = usb_autopm_get_interface(dev->intf);
+               if (status < 0)
+                       goto skip_reset;
                if(info->link_reset && (retval = info->link_reset(dev)) < 0) {
+                       usb_autopm_put_interface(dev->intf);
+skip_reset:
                        devinfo(dev, "link reset failed (%d) usbnet usb-%s-%s, %s",
                                retval,
                                dev->udev->bus->bus_name, dev->udev->devpath,
                                info->description);
+               } else {
+                       usb_autopm_put_interface(dev->intf);
                }
        }
 
@@ -971,6 +1010,7 @@ static void tx_complete (struct urb *urb)
                case -EPROTO:
                case -ETIME:
                case -EILSEQ:
+                       usb_mark_last_busy(dev->udev);
                        if (!timer_pending (&dev->delay)) {
                                mod_timer (&dev->delay,
                                        jiffies + THROTTLE_JIFFIES);
@@ -987,6 +1027,7 @@ static void tx_complete (struct urb *urb)
                }
        }
 
+       usb_autopm_put_interface_async(dev->intf);
        urb->dev = NULL;
        entry->state = tx_done;
        defer_bh(dev, skb, &dev->txq);
@@ -1057,14 +1098,34 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
                }
        }
 
-       spin_lock_irqsave (&dev->txq.lock, flags);
+       spin_lock_irqsave(&dev->txq.lock, flags);
+       retval = usb_autopm_get_interface_async(dev->intf);
+       if (retval < 0) {
+               spin_unlock_irqrestore(&dev->txq.lock, flags);
+               goto drop;
+       }
+
+#ifdef CONFIG_PM
+       /* if this triggers the device is still a sleep */
+       if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) {
+               /* transmission will be done in resume */
+               usb_anchor_urb(urb, &dev->deferred);
+               /* no use to process more packets */
+               netif_stop_queue(net);
+               spin_unlock_irqrestore(&dev->txq.lock, flags);
+               devdbg(dev, "Delaying transmission for resumption");
+               goto deferred;
+       }
+#endif
 
        switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
        case -EPIPE:
                netif_stop_queue (net);
                usbnet_defer_kevent (dev, EVENT_TX_HALT);
+               usb_autopm_put_interface_async(dev->intf);
                break;
        default:
+               usb_autopm_put_interface_async(dev->intf);
                if (netif_msg_tx_err (dev))
                        devdbg (dev, "tx: submit urb err %d", retval);
                break;
@@ -1088,6 +1149,9 @@ drop:
                devdbg (dev, "> tx, len %d, type 0x%x",
                        length, skb->protocol);
        }
+#ifdef CONFIG_PM
+deferred:
+#endif
        return NETDEV_TX_OK;
 }
 EXPORT_SYMBOL_GPL(usbnet_start_xmit);
@@ -1263,6 +1327,7 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod)
        dev->bh.func = usbnet_bh;
        dev->bh.data = (unsigned long) dev;
        INIT_WORK (&dev->kevent, kevent);
+       init_usb_anchor(&dev->deferred);
        dev->delay.function = usbnet_bh;
        dev->delay.data = (unsigned long) dev;
        init_timer (&dev->delay);
@@ -1382,13 +1447,23 @@ int usbnet_suspend (struct usb_interface *intf, pm_message_t message)
        struct usbnet           *dev = usb_get_intfdata(intf);
 
        if (!dev->suspend_count++) {
+               spin_lock_irq(&dev->txq.lock);
+               /* don't autosuspend while transmitting */
+               if (dev->txq.qlen && (message.event & PM_EVENT_AUTO)) {
+                       spin_unlock_irq(&dev->txq.lock);
+                       return -EBUSY;
+               } else {
+                       set_bit(EVENT_DEV_ASLEEP, &dev->flags);
+                       spin_unlock_irq(&dev->txq.lock);
+               }
                /*
                 * accelerate emptying of the rx and queues, to avoid
                 * having everything error out.
                 */
                netif_device_detach (dev->net);
-               (void) unlink_urbs (dev, &dev->rxq);
-               (void) unlink_urbs (dev, &dev->txq);
+               usbnet_terminate_urbs(dev);
+               usb_kill_urb(dev->interrupt);
+
                /*
                 * reattach so runtime management can use and
                 * wake the device
@@ -1402,10 +1477,34 @@ EXPORT_SYMBOL_GPL(usbnet_suspend);
 int usbnet_resume (struct usb_interface *intf)
 {
        struct usbnet           *dev = usb_get_intfdata(intf);
+       struct sk_buff          *skb;
+       struct urb              *res;
+       int                     retval;
+
+       if (!--dev->suspend_count) {
+               spin_lock_irq(&dev->txq.lock);
+               while ((res = usb_get_from_anchor(&dev->deferred))) {
+
+                       printk(KERN_INFO"%s has delayed data\n", __func__);
+                       skb = (struct sk_buff *)res->context;
+                       retval = usb_submit_urb(res, GFP_ATOMIC);
+                       if (retval < 0) {
+                               dev_kfree_skb_any(skb);
+                               usb_free_urb(res);
+                               usb_autopm_put_interface_async(dev->intf);
+                       } else {
+                               dev->net->trans_start = jiffies;
+                               __skb_queue_tail(&dev->txq, skb);
+                       }
+               }
 
-       if (!--dev->suspend_count)
+               smp_mb();
+               clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
+               spin_unlock_irq(&dev->txq.lock);
+               if (!(dev->txq.qlen >= TX_QLEN(dev)))
+                       netif_start_queue(dev->net);
                tasklet_schedule (&dev->bh);
-
+       }
        return 0;
 }
 EXPORT_SYMBOL_GPL(usbnet_resume);

diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h
index 8c84881..8ce6135 100644 (file)
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -55,6 +55,7 @@ struct usbnet {
        struct sk_buff_head     done;
        struct sk_buff_head     rxq_pause;
        struct urb              *interrupt;
+       struct usb_anchor       deferred;
        struct tasklet_struct   bh;
 
        struct work_struct      kevent;
@@ -65,6 +66,8 @@ struct usbnet {
 #              define EVENT_STS_SPLIT  3
 #              define EVENT_LINK_RESET 4
 #              define EVENT_RX_PAUSED  5
+#              define EVENT_DEV_WAKING 6
+#              define EVENT_DEV_ASLEEP 7
 };
 
 static inline struct usb_driver *driver_of(struct usb_interface *intf)
@@ -109,6 +112,9 @@ struct driver_info {
        /* see if peer is connected ... can sleep */
        int     (*check_connect)(struct usbnet *);
 
+       /* (dis)activate runtime power management */
+       int     (*manage_power)(struct usbnet *, int);
+
        /* for status polling */
        void    (*status)(struct usbnet *, struct urb *);