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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: Dan Williams <dcbw@redhat.com>
Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Williams 2013-05-06 11:29:23 +00:00 committed by David S. Miller
parent 7fdb7846c9
commit 6eecdc5f95
2 changed files with 76 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

77
drivers/net/usb/usbnet.c
View File

@ -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))) {

5
include/linux/usb/usbnet.h
View File

@ -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 */