From 6eecdc5f95a393cb558503123eae9a9a6642e835 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Mon, 6 May 2013 11:29:23 +0000 Subject: [PATCH] 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 Acked-by: Oliver Neukum Signed-off-by: David S. Miller --- drivers/net/usb/usbnet.c | 77 ++++++++++++++++++++++++++++++++++++++++++---- include/linux/usb/usbnet.h | 5 +++ 2 files changed, 76 insertions(+), 6 deletions(-) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 1e5a9b7..f95cb03 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -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))) { diff --git a/include/linux/usb/usbnet.h b/include/linux/usb/usbnet.h index da46327..f18d641 100644 --- a/include/linux/usb/usbnet.h +++ b/include/linux/usb/usbnet.h @@ -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 */ -- 2.7.4