From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Williams Subject: [PATCH 1/2 v4] usbnet: allow status interrupt URB to always be active Date: Tue, 09 Apr 2013 18:02:27 -0500 Message-ID: <1365548547.23372.2.camel@dcbw.foobar.com> References: <20110727141246.GC29616@orbit.nwl.cc> <1357318096.5370.15.camel@dcbw.foobar.com> <1364488207.1877.20.camel@dcbw.foobar.com> <1364832288.3059.12.camel@dcbw.foobar.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Oliver Neukum , Elina Pasheva , Network Development , linux-usb , Rory Filer , Phil Sutter To: Ming Lei Return-path: Received: from mx1.redhat.com ([209.132.183.28]:61590 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751767Ab3DIXB0 (ORCPT ); Tue, 9 Apr 2013 19:01:26 -0400 In-Reply-To: <1364832288.3059.12.camel@dcbw.foobar.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 --- drivers/net/usb/usbnet.c | 79 ++++++++++++++++++++++++++++++++++++++++++---- include/linux/usb/usbnet.h | 5 +++ 2 files changed, 77 insertions(+), 7 deletions(-) diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c index 51f3192..e8b363a 100644 --- a/drivers/net/usb/usbnet.c +++ b/drivers/net/usb/usbnet.c @@ -42,7 +42,7 @@ #include #include #include -#include +#include "usbnet.h" #include #include #include @@ -252,6 +252,70 @@ static int init_status (struct usbnet *dev, struct usb_interface *intf) return 0; } +/* Submit the interrupt URB if it hasn't been submitted yet */ +static int __usbnet_status_start(struct usbnet *dev, gfp_t mem_flags, + bool force) +{ + int ret = 0; + bool submit = false; + + if (!dev->interrupt) + return 0; + + mutex_lock(&dev->interrupt_mutex); + + if (force) { + /* Only submit now if the URB was previously submitted */ + if (dev->interrupt_count) + submit = true; + } else if (++dev->interrupt_count == 1) + submit = true; + + if (submit) + 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; +} + +int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags) +{ + /* Only drivers that implement a status hook should call this */ + BUG_ON(dev->interrupt == NULL); + + if (test_bit(EVENT_DEV_ASLEEP, &dev->flags)) + return -EINVAL; + + return __usbnet_status_start(dev, mem_flags, false); +} +EXPORT_SYMBOL_GPL(usbnet_status_start); + +/* Kill the interrupt URB if all submitters want it killed */ +static void __usbnet_status_stop(struct usbnet *dev, bool force) +{ + if (dev->interrupt) { + mutex_lock(&dev->interrupt_mutex); + if (!force) + BUG_ON(dev->interrupt_count == 0); + + if (force || --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); + } +} + +void usbnet_status_stop(struct usbnet *dev) +{ + __usbnet_status_stop(dev, false); +} +EXPORT_SYMBOL_GPL(usbnet_status_stop); + /* 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); @@ -1430,6 +1494,8 @@ 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"); @@ -1565,7 +1631,7 @@ 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(dev, true); /* * reattach so runtime management can use and @@ -1585,9 +1651,8 @@ 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 URBs if they were submitted at suspend */ + __usbnet_status_start(dev, GFP_NOIO, true); 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 0e5ac93..d71f44c 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; @@ -246,4 +248,7 @@ extern int usbnet_nway_reset(struct net_device *net); extern int usbnet_manage_power(struct usbnet *, int); +int usbnet_status_start(struct usbnet *dev, gfp_t mem_flags); +void usbnet_status_stop(struct usbnet *dev); + #endif /* __LINUX_USB_USBNET_H */ -- 1.8.1.4