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usbnet & cdc-ether: Autosuspend for online devices
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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>
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Oliver Neukum authored and David S. Miller committed Dec 3, 2009
1 parent 7f51579 commit 69ee472
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Showing 3 changed files with 142 additions and 29 deletions.
8 changes: 8 additions & 0 deletions drivers/net/usb/cdc_ether.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -411,13 +411,20 @@ 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,
// .check_connect = cdc_check_connect,
.bind = cdc_bind,
.unbind = usbnet_cdc_unbind,
.status = cdc_status,
.manage_power = cdc_manage_power,
};

static const struct driver_info mbm_info = {
Expand Down Expand Up @@ -619,6 +626,7 @@ static struct usb_driver cdc_driver = {
.suspend = usbnet_suspend,
.resume = usbnet_resume,
.reset_resume = usbnet_resume,
.supports_autosuspend = 1,
};


Expand Down
157 changes: 128 additions & 29 deletions drivers/net/usb/usbnet.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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);

Expand All @@ -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);

Expand All @@ -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;
}
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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 {
Expand All @@ -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 {
Expand All @@ -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);
}
}
Expand All @@ -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);
}
}

Expand Down Expand Up @@ -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);
Expand All @@ -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);
Expand Down Expand Up @@ -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;
Expand All @@ -1088,6 +1149,9 @@ netdev_tx_t usbnet_start_xmit (struct sk_buff *skb,
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);
Expand Down Expand Up @@ -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);
Expand Down Expand Up @@ -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
Expand All @@ -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);
Expand Down
6 changes: 6 additions & 0 deletions include/linux/usb/usbnet.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
Expand All @@ -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)
Expand Down Expand Up @@ -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 *);

Expand Down

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