From: Alan Stern Date: Tue, 13 Mar 2007 20:37:30 +0000 (-0400) Subject: USB: separate autosuspend from external suspend X-Git-Tag: v2.6.22-rc1~1117^2~57 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6b157c9bf3bace6eeb4a973da63923ef24995cce;p=linux-2.6 USB: separate autosuspend from external suspend This patch (as866) adds new entry points for external USB device suspend and resume requests, as opposed to internally-generated autosuspend or autoresume. It also changes the existing remote-wakeup code paths to use the new routines, since remote wakeup is not the same as autoresume. As part of the change, it turns out to be necessary to do remote wakeup of root hubs from a workqueue. We had been using khubd, but it does autoresume rather than an external resume. Using the ksuspend_usb_wq workqueue for this purpose seemed a logical choice. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index 8c0a7de612..abea48de87 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -1424,48 +1424,84 @@ void usb_autosuspend_work(struct work_struct *work) #endif /* CONFIG_USB_SUSPEND */ -static int usb_suspend(struct device *dev, pm_message_t message) +/** + * usb_external_suspend_device - external suspend of a USB device and its interfaces + * @udev: the usb_device to suspend + * @msg: Power Management message describing this state transition + * + * This routine handles external suspend requests: ones not generated + * internally by a USB driver (autosuspend) but rather coming from the user + * (via sysfs) or the PM core (system sleep). The suspend will be carried + * out regardless of @udev's usage counter or those of its interfaces, + * and regardless of whether or not remote wakeup is enabled. Of course, + * interface drivers still have the option of failing the suspend (if + * there are unsuspended children, for example). + * + * The caller must hold @udev's device lock. + */ +int usb_external_suspend_device(struct usb_device *udev, pm_message_t msg) { int status; - if (is_usb_device(dev)) { - struct usb_device *udev = to_usb_device(dev); - - usb_pm_lock(udev); - udev->auto_pm = 0; - status = usb_suspend_both(udev, message); - usb_pm_unlock(udev); - } else - status = 0; + usb_pm_lock(udev); + udev->auto_pm = 0; + status = usb_suspend_both(udev, msg); + usb_pm_unlock(udev); return status; } -static int usb_resume(struct device *dev) +/** + * usb_external_resume_device - external resume of a USB device and its interfaces + * @udev: the usb_device to resume + * + * This routine handles external resume requests: ones not generated + * internally by a USB driver (autoresume) but rather coming from the user + * (via sysfs), the PM core (system resume), or the device itself (remote + * wakeup). @udev's usage counter is unaffected. + * + * The caller must hold @udev's device lock. + */ +int usb_external_resume_device(struct usb_device *udev) { int status; - if (is_usb_device(dev)) { - struct usb_device *udev = to_usb_device(dev); - - usb_pm_lock(udev); - udev->auto_pm = 0; - status = usb_resume_both(udev); - usb_pm_unlock(udev); + usb_pm_lock(udev); + udev->auto_pm = 0; + status = usb_resume_both(udev); + usb_pm_unlock(udev); - /* Rebind drivers that had no suspend method? */ - } else - status = 0; + /* Now that the device is awake, we can start trying to autosuspend + * it again. */ + if (status == 0) + usb_try_autosuspend_device(udev); return status; } +static int usb_suspend(struct device *dev, pm_message_t message) +{ + if (!is_usb_device(dev)) /* Ignore PM for interfaces */ + return 0; + return usb_external_suspend_device(to_usb_device(dev), message); +} + +static int usb_resume(struct device *dev) +{ + if (!is_usb_device(dev)) /* Ignore PM for interfaces */ + return 0; + return usb_external_resume_device(to_usb_device(dev)); +} + +#else + +#define usb_suspend NULL +#define usb_resume NULL + #endif /* CONFIG_PM */ struct bus_type usb_bus_type = { .name = "usb", .match = usb_device_match, .uevent = usb_uevent, -#ifdef CONFIG_PM .suspend = usb_suspend, .resume = usb_resume, -#endif }; diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index af7aed1139..8bc3ce6d96 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -37,6 +37,7 @@ #include #include #include +#include #include @@ -1298,14 +1299,25 @@ int hcd_bus_resume (struct usb_bus *bus) return status; } +/* Workqueue routine for root-hub remote wakeup */ +static void hcd_resume_work(struct work_struct *work) +{ + struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work); + struct usb_device *udev = hcd->self.root_hub; + + usb_lock_device(udev); + usb_external_resume_device(udev); + usb_unlock_device(udev); +} + /** * usb_hcd_resume_root_hub - called by HCD to resume its root hub * @hcd: host controller for this root hub * * The USB host controller calls this function when its root hub is * suspended (with the remote wakeup feature enabled) and a remote - * wakeup request is received. It queues a request for khubd to - * resume the root hub (that is, manage its downstream ports again). + * wakeup request is received. The routine submits a workqueue request + * to resume the root hub (that is, manage its downstream ports again). */ void usb_hcd_resume_root_hub (struct usb_hcd *hcd) { @@ -1313,7 +1325,7 @@ void usb_hcd_resume_root_hub (struct usb_hcd *hcd) spin_lock_irqsave (&hcd_root_hub_lock, flags); if (hcd->rh_registered) - usb_resume_root_hub (hcd->self.root_hub); + queue_work(ksuspend_usb_wq, &hcd->wakeup_work); spin_unlock_irqrestore (&hcd_root_hub_lock, flags); } EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub); @@ -1502,6 +1514,9 @@ struct usb_hcd *usb_create_hcd (const struct hc_driver *driver, init_timer(&hcd->rh_timer); hcd->rh_timer.function = rh_timer_func; hcd->rh_timer.data = (unsigned long) hcd; +#ifdef CONFIG_PM + INIT_WORK(&hcd->wakeup_work, hcd_resume_work); +#endif hcd->driver = driver; hcd->product_desc = (driver->product_desc) ? driver->product_desc : @@ -1668,6 +1683,10 @@ void usb_remove_hcd(struct usb_hcd *hcd) hcd->rh_registered = 0; spin_unlock_irq (&hcd_root_hub_lock); +#ifdef CONFIG_PM + flush_workqueue(ksuspend_usb_wq); +#endif + mutex_lock(&usb_bus_list_lock); usb_disconnect(&hcd->self.root_hub); mutex_unlock(&usb_bus_list_lock); diff --git a/drivers/usb/core/hcd.h b/drivers/usb/core/hcd.h index 2a269ca205..ef50fa494e 100644 --- a/drivers/usb/core/hcd.h +++ b/drivers/usb/core/hcd.h @@ -68,6 +68,9 @@ struct usb_hcd { struct timer_list rh_timer; /* drives root-hub polling */ struct urb *status_urb; /* the current status urb */ +#ifdef CONFIG_PM + struct work_struct wakeup_work; /* for remote wakeup */ +#endif /* * hardware info/state diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 7a6028599d..19abe81bab 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1855,12 +1855,7 @@ static int remote_wakeup(struct usb_device *udev) usb_lock_device(udev); if (udev->state == USB_STATE_SUSPENDED) { dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-"); - status = usb_autoresume_device(udev); - - /* Give the interface drivers a chance to do something, - * then autosuspend the device again. */ - if (status == 0) - usb_autosuspend_device(udev); + status = usb_external_resume_device(udev); } usb_unlock_device(udev); return status; @@ -1984,13 +1979,6 @@ static inline int remote_wakeup(struct usb_device *udev) #define hub_resume NULL #endif -void usb_resume_root_hub(struct usb_device *hdev) -{ - struct usb_hub *hub = hdev_to_hub(hdev); - - kick_khubd(hub); -} - /* USB 2.0 spec, 7.1.7.3 / fig 7-29: * diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 82338f4978..138252e0a1 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -49,7 +49,8 @@ const char *usbcore_name = "usbcore"; static int nousb; /* Disable USB when built into kernel image */ -struct workqueue_struct *ksuspend_usb_wq; /* For autosuspend */ +/* Workqueue for autosuspend and for remote wakeup of root hubs */ +struct workqueue_struct *ksuspend_usb_wq; #ifdef CONFIG_USB_SUSPEND static int usb_autosuspend_delay = 2; /* Default delay value, diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h index b98bc0d381..c94379e55f 100644 --- a/drivers/usb/core/usb.h +++ b/drivers/usb/core/usb.h @@ -21,7 +21,6 @@ extern char *usb_cache_string(struct usb_device *udev, int index); extern int usb_set_configuration(struct usb_device *dev, int configuration); extern void usb_kick_khubd(struct usb_device *dev); -extern void usb_resume_root_hub(struct usb_device *dev); extern int usb_match_device(struct usb_device *dev, const struct usb_device_id *id); @@ -37,6 +36,9 @@ extern void usb_host_cleanup(void); extern void usb_autosuspend_work(struct work_struct *work); extern int usb_port_suspend(struct usb_device *dev); extern int usb_port_resume(struct usb_device *dev); +extern int usb_external_suspend_device(struct usb_device *udev, + pm_message_t msg); +extern int usb_external_resume_device(struct usb_device *udev); static inline void usb_pm_lock(struct usb_device *udev) {