Commit 6eecdc5f authored by Dan Williams's avatar Dan Williams Committed by David S. Miller
Browse files

usbnet: allow status interrupt URB to always be active 



Some drivers (sierra_net) need the status interrupt URB
active even when the device is closed, because they receive
custom indications from firmware.  Add functions to refcount
the status interrupt URB submit/kill operation so that
sub-drivers and the generic driver don't fight over whether
the status interrupt URB is active or not.

A sub-driver can call usbnet_status_start() at any time, but
the URB is only submitted the first time the function is
called.  Likewise, when the sub-driver is done with the URB,
it calls usbnet_status_stop() but the URB is only killed when
all users have stopped it.  The URB is still killed and
re-submitted for suspend/resume, as before, with the same
refcount it had at suspend.

Signed-off-by: default avatarDan Williams <dcbw@redhat.com>
Acked-by: default avatarOliver Neukum <oliver@neukum.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7fdb7846

drivers/net/usb/usbnet.c

+71 −6
Original line number Diff line number Diff line
@@ -252,6 +252,70 @@ static int init_status (struct usbnet *dev, struct usb_interface *intf) 
	return 0;

}



/* Submit the interrupt URB if not previously submitted, increasing refcount */

int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags)

{

	int ret = 0;



	WARN_ON_ONCE(dev->interrupt == NULL);

	if (dev->interrupt) {

		mutex_lock(&dev->interrupt_mutex);



		if (++dev->interrupt_count == 1)

			ret = usb_submit_urb(dev->interrupt, mem_flags);



		dev_dbg(&dev->udev->dev, "incremented interrupt URB count to %d\n",

			dev->interrupt_count);

		mutex_unlock(&dev->interrupt_mutex);

	}

	return ret;

}

EXPORT_SYMBOL_GPL(usbnet_status_start);



/* For resume; submit interrupt URB if previously submitted */

static int __usbnet_status_start_force(struct usbnet *dev, gfp_t mem_flags)

{

	int ret = 0;



	mutex_lock(&dev->interrupt_mutex);

	if (dev->interrupt_count) {

		ret = usb_submit_urb(dev->interrupt, mem_flags);

		dev_dbg(&dev->udev->dev,

			"submitted interrupt URB for resume\n");

	}

	mutex_unlock(&dev->interrupt_mutex);

	return ret;

}



/* Kill the interrupt URB if all submitters want it killed */

void usbnet_status_stop(struct usbnet *dev)

{

	if (dev->interrupt) {

		mutex_lock(&dev->interrupt_mutex);

		WARN_ON(dev->interrupt_count == 0);



		if (dev->interrupt_count && --dev->interrupt_count == 0)

			usb_kill_urb(dev->interrupt);



		dev_dbg(&dev->udev->dev,

			"decremented interrupt URB count to %d\n",

			dev->interrupt_count);

		mutex_unlock(&dev->interrupt_mutex);

	}

}

EXPORT_SYMBOL_GPL(usbnet_status_stop);



/* For suspend; always kill interrupt URB */

static void __usbnet_status_stop_force(struct usbnet *dev)

{

	if (dev->interrupt) {

		mutex_lock(&dev->interrupt_mutex);

		usb_kill_urb(dev->interrupt);

		dev_dbg(&dev->udev->dev, "killed interrupt URB for suspend\n");

		mutex_unlock(&dev->interrupt_mutex);

	}

}



/* Passes this packet up the stack, updating its accounting.

 * Some link protocols batch packets, so their rx_fixup paths

 * can return clones as well as just modify the original skb.
@@ -725,7 +789,7 @@ int usbnet_stop (struct net_device *net) 
	if (!(info->flags & FLAG_AVOID_UNLINK_URBS))

		usbnet_terminate_urbs(dev);



	usb_kill_urb(dev->interrupt);

	usbnet_status_stop(dev);



	usbnet_purge_paused_rxq(dev);
@@ -787,7 +851,7 @@ int usbnet_open (struct net_device *net) 


	/* start any status interrupt transfer */

	if (dev->interrupt) {

		retval = usb_submit_urb (dev->interrupt, GFP_KERNEL);

		retval = usbnet_status_start(dev, GFP_KERNEL);

		if (retval < 0) {

			netif_err(dev, ifup, dev->net,

				  "intr submit %d\n", retval);
@@ -1458,6 +1522,8 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) 
	dev->delay.data = (unsigned long) dev;

	init_timer (&dev->delay);

	mutex_init (&dev->phy_mutex);

	mutex_init(&dev->interrupt_mutex);

	dev->interrupt_count = 0;



	dev->net = net;

	strcpy (net->name, "usb%d");
@@ -1593,7 +1659,7 @@ int usbnet_suspend (struct usb_interface *intf, pm_message_t message) 
		 */

		netif_device_detach (dev->net);

		usbnet_terminate_urbs(dev);

		usb_kill_urb(dev->interrupt);

		__usbnet_status_stop_force(dev);



		/*

		 * reattach so runtime management can use and
@@ -1613,9 +1679,8 @@ int usbnet_resume (struct usb_interface *intf) 
	int                     retval;



	if (!--dev->suspend_count) {

		/* resume interrupt URBs */

		if (dev->interrupt && test_bit(EVENT_DEV_OPEN, &dev->flags))

			usb_submit_urb(dev->interrupt, GFP_NOIO);

		/* resume interrupt URB if it was previously submitted */

		__usbnet_status_start_force(dev, GFP_NOIO);



		spin_lock_irq(&dev->txq.lock);

		while ((res = usb_get_from_anchor(&dev->deferred))) {

include/linux/usb/usbnet.h

+5 −0
Original line number Diff line number Diff line
@@ -56,6 +56,8 @@ struct usbnet { 
	struct sk_buff_head	done;

	struct sk_buff_head	rxq_pause;

	struct urb		*interrupt;

	unsigned		interrupt_count;

	struct mutex		interrupt_mutex;

	struct usb_anchor	deferred;

	struct tasklet_struct	bh;
@@ -248,4 +250,7 @@ extern int usbnet_nway_reset(struct net_device *net); 
extern int usbnet_manage_power(struct usbnet *, int);

extern void usbnet_link_change(struct usbnet *, bool, bool);



extern int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags);

extern void usbnet_status_stop(struct usbnet *dev);



#endif /* __LINUX_USB_USBNET_H */

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