Hi,
this allows the use of remote wakeup to autosuspend online
devices. What do you think?
Regards
Oliver
--
commit 7f2d9a0440f6453462bd7bf95f77eda17c16d865
Author: Oliver Neukum <oliver@xxxxxxxxxx>
Date: Fri Aug 28 15:49:15 2009 +0200
usb: usbnet: runtime power management for active connections
Devices that support remote wakeup can be autosuspended even while the
interface is up. Transmissions are queued and processed after the device
has been woken up.
diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 4a6aff5..8ee5bd7 100644
--- 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,
@@ -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,
};
/*-------------------------------------------------------------------------*/
@@ -570,6 +577,7 @@ static struct usb_driver cdc_driver = {
.disconnect = usbnet_disconnect,
.suspend = usbnet_suspend,
.resume = usbnet_resume,
+ .supports_autosuspend = 1,
};
diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index edfd9e1..c21b3d2 100644
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -575,6 +575,7 @@ EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
int usbnet_stop (struct net_device *net)
{
struct usbnet *dev = netdev_priv(net);
+ struct driver_info *info = dev->driver_info;
int temp;
DECLARE_WAIT_QUEUE_HEAD_ONSTACK (unlink_wakeup);
DECLARE_WAITQUEUE (wait, current);
@@ -612,7 +613,10 @@ 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;
}
@@ -693,6 +697,13 @@ 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);
@@ -822,6 +833,7 @@ kevent (struct work_struct *work)
if (test_bit (EVENT_TX_HALT, &dev->flags)) {
unlink_urbs (dev, &dev->txq);
status = usb_clear_halt (dev->udev, dev->out);
+ usb_autopm_put_interface(dev->intf);
if (status < 0
&& status != -EPIPE
&& status != -ESHUTDOWN) {
@@ -893,17 +905,20 @@ static void tx_complete (struct urb *urb)
if (urb->status == 0) {
dev->net->stats.tx_packets++;
dev->net->stats.tx_bytes += entry->length;
+ usb_autopm_put_interface_async(dev->intf);
} else {
dev->net->stats.tx_errors++;
switch (urb->status) {
case -EPIPE:
+ /* we do not allow autosuspension */
usbnet_defer_kevent (dev, EVENT_TX_HALT);
break;
/* software-driven interface shutdown */
case -ECONNRESET: // async unlink
case -ESHUTDOWN: // hardware gone
+ usb_autopm_put_interface_async(dev->intf);
break;
// like rx, tx gets controller i/o faults during khubd delays
@@ -911,6 +926,7 @@ 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);
@@ -919,8 +935,10 @@ static void tx_complete (struct urb *urb)
urb->status);
}
netif_stop_queue (dev->net);
+ 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 err %d", entry->urb->status);
break;
@@ -996,8 +1014,29 @@ int usbnet_start_xmit (struct sk_buff *skb, struct net_device *net)
}
}
+
+
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 */
+ dev->deferred = urb;
+ /* no use to process more packets */
+ netif_stop_queue(net);
+ spin_unlock_irqrestore(&dev->txq.lock, flags);
+ retval = NET_XMIT_SUCCESS;
+ goto deferred;
+ }
+#endif
+
switch ((retval = usb_submit_urb (urb, GFP_ATOMIC))) {
case -EPIPE:
netif_stop_queue (net);
@@ -1028,6 +1067,7 @@ drop:
devdbg (dev, "> tx, len %d, type 0x%x",
length, skb->protocol);
}
+deferred:
return retval;
}
EXPORT_SYMBOL_GPL(usbnet_start_xmit);
@@ -1303,6 +1343,15 @@ 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.
@@ -1322,11 +1371,34 @@ EXPORT_SYMBOL_GPL(usbnet_suspend);
int usbnet_resume (struct usb_interface *intf)
{
- struct usbnet *dev = usb_get_intfdata(intf);
-
- if (!--dev->suspend_count)
+ 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);
+ res = dev->deferred;
+ dev->deferred = NULL;
+ clear_bit(EVENT_DEV_ASLEEP, &dev->flags);
+ spin_unlock_irq(&dev->txq.lock);
+ if (res) {
+ retval = usb_submit_urb(res, GFP_NOIO);
+ if (retval < 0) {
+ usb_free_urb(res);
+ netif_start_queue(dev->net);
+ usb_autopm_put_interface_async(dev->intf);
+ } else {
+ skb = (struct sk_buff *)res->context;
+ dev->net->trans_start = jiffies;
+ __skb_queue_tail (&dev->txq, skb);
+ 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 310e18a..6fa0545 100644
--- a/include/linux/usb/usbnet.h
+++ b/include/linux/usb/usbnet.h
@@ -54,6 +54,7 @@ struct usbnet {
struct sk_buff_head txq;
struct sk_buff_head done;
struct urb *interrupt;
+ struct urb *deferred;
struct tasklet_struct bh;
struct work_struct kevent;
@@ -63,6 +64,8 @@ struct usbnet {
# define EVENT_RX_MEMORY 2
# define EVENT_STS_SPLIT 3
# define EVENT_LINK_RESET 4
+# define EVENT_DEV_WAKING 5
+# define EVENT_DEV_ASLEEP 6
};
static inline struct usb_driver *driver_of(struct usb_interface *intf)
@@ -100,6 +103,9 @@ 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 *);
--
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