From 645daaab0b6adc35c1838df2a82f9d729fdb1767 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Wed, 30 Aug 2006 15:47:02 -0400 Subject: usbcore: add autosuspend/autoresume infrastructure This patch (as739) adds the basic infrastructure for USB autosuspend and autoresume. The main features are: PM usage counters added to struct usb_device and struct usb_interface, indicating whether it's okay to autosuspend them or they are currently in use. Flag added to usb_device indicating whether the current suspend/resume operation originated from outside or as an autosuspend/autoresume. Flag added to usb_driver indicating whether the driver supports autosuspend. If not, no device bound to the driver will be autosuspended. Mutex added to usb_device for protecting PM operations. Unlike the device semaphore, the locking rule for the pm_mutex is that you must acquire the locks going _up_ the device tree. New routines handling autosuspend/autoresume requests for interfaces and devices. Suspend and resume requests are propagated up the device tree (but not outside the USB subsystem). work_struct added to usb_device, for carrying out delayed autosuspend requests. Autoresume added (and autosuspend prevented) during probe and disconnect. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/usb.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) (limited to 'drivers/usb/core/usb.c') diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index b0c0a993338..6b029cdb867 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -168,6 +168,10 @@ static void usb_release_dev(struct device *dev) udev = to_usb_device(dev); +#ifdef CONFIG_PM + cancel_delayed_work(&udev->autosuspend); + flush_scheduled_work(); +#endif usb_destroy_configuration(udev); usb_put_hcd(bus_to_hcd(udev->bus)); kfree(udev->product); @@ -176,6 +180,21 @@ static void usb_release_dev(struct device *dev) kfree(udev); } +#ifdef CONFIG_PM + +/* usb_autosuspend_work - callback routine to autosuspend a USB device */ +static void usb_autosuspend_work(void *_udev) +{ + struct usb_device *udev = _udev; + + mutex_lock_nested(&udev->pm_mutex, udev->level); + udev->auto_pm = 1; + usb_suspend_both(udev, PMSG_SUSPEND); + mutex_unlock(&udev->pm_mutex); +} + +#endif + /** * usb_alloc_dev - usb device constructor (usbcore-internal) * @parent: hub to which device is connected; null to allocate a root hub @@ -251,6 +270,10 @@ usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1) dev->parent = parent; INIT_LIST_HEAD(&dev->filelist); +#ifdef CONFIG_PM + mutex_init(&dev->pm_mutex); + INIT_WORK(&dev->autosuspend, usb_autosuspend_work, dev); +#endif return dev; } -- cgit v1.2.3