diff options
Diffstat (limited to 'drivers/usb/core/driver.c')
-rw-r--r-- | drivers/usb/core/driver.c | 255 |
1 files changed, 160 insertions, 95 deletions
diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c index e6dd2b9210f..b9f7f90aef8 100644 --- a/drivers/usb/core/driver.c +++ b/drivers/usb/core/driver.c @@ -574,23 +574,10 @@ static int usb_device_match(struct device *dev, struct device_driver *drv) } #ifdef CONFIG_HOTPLUG - -/* - * This sends an uevent to userspace, typically helping to load driver - * or other modules, configure the device, and more. Drivers can provide - * a MODULE_DEVICE_TABLE to help with module loading subtasks. - * - * We're called either from khubd (the typical case) or from root hub - * (init, kapmd, modprobe, rmmod, etc), but the agents need to handle - * delays in event delivery. Use sysfs (and DEVPATH) to make sure the - * device (and this configuration!) are still present. - */ static int usb_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size) { - struct usb_interface *intf; struct usb_device *usb_dev; - struct usb_host_interface *alt; int i = 0; int length = 0; @@ -600,13 +587,11 @@ static int usb_uevent(struct device *dev, char **envp, int num_envp, /* driver is often null here; dev_dbg() would oops */ pr_debug ("usb %s: uevent\n", dev->bus_id); - if (is_usb_device(dev)) { + if (is_usb_device(dev)) usb_dev = to_usb_device(dev); - alt = NULL; - } else { - intf = to_usb_interface(dev); + else { + struct usb_interface *intf = to_usb_interface(dev); usb_dev = interface_to_usbdev(intf); - alt = intf->cur_altsetting; } if (usb_dev->devnum < 0) { @@ -621,9 +606,7 @@ static int usb_uevent(struct device *dev, char **envp, int num_envp, #ifdef CONFIG_USB_DEVICEFS /* If this is available, userspace programs can directly read * all the device descriptors we don't tell them about. Or - * even act as usermode drivers. - * - * FIXME reduce hardwired intelligence here + * act as usermode drivers. */ if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, @@ -650,44 +633,29 @@ static int usb_uevent(struct device *dev, char **envp, int num_envp, usb_dev->descriptor.bDeviceProtocol)) return -ENOMEM; - if (!is_usb_device(dev)) { - - if (add_uevent_var(envp, num_envp, &i, + if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, - "INTERFACE=%d/%d/%d", - alt->desc.bInterfaceClass, - alt->desc.bInterfaceSubClass, - alt->desc.bInterfaceProtocol)) - return -ENOMEM; + "BUSNUM=%03d", + usb_dev->bus->busnum)) + return -ENOMEM; - if (add_uevent_var(envp, num_envp, &i, + if (add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length, - "MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X", - le16_to_cpu(usb_dev->descriptor.idVendor), - le16_to_cpu(usb_dev->descriptor.idProduct), - le16_to_cpu(usb_dev->descriptor.bcdDevice), - usb_dev->descriptor.bDeviceClass, - usb_dev->descriptor.bDeviceSubClass, - usb_dev->descriptor.bDeviceProtocol, - alt->desc.bInterfaceClass, - alt->desc.bInterfaceSubClass, - alt->desc.bInterfaceProtocol)) - return -ENOMEM; - } + "DEVNUM=%03d", + usb_dev->devnum)) + return -ENOMEM; envp[i] = NULL; - return 0; } #else static int usb_uevent(struct device *dev, char **envp, - int num_envp, char *buffer, int buffer_size) + int num_envp, char *buffer, int buffer_size) { return -ENODEV; } - #endif /* CONFIG_HOTPLUG */ /** @@ -872,8 +840,10 @@ static int usb_resume_device(struct usb_device *udev) done: // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); - if (status == 0) + if (status == 0) { + udev->autoresume_disabled = 0; udev->dev.power.power_state.event = PM_EVENT_ON; + } return status; } @@ -962,6 +932,7 @@ static int autosuspend_check(struct usb_device *udev) { int i; struct usb_interface *intf; + unsigned long suspend_time; /* For autosuspend, fail fast if anything is in use or autosuspend * is disabled. Also fail if any interfaces require remote wakeup @@ -970,9 +941,10 @@ static int autosuspend_check(struct usb_device *udev) udev->do_remote_wakeup = device_may_wakeup(&udev->dev); if (udev->pm_usage_cnt > 0) return -EBUSY; - if (!udev->autosuspend_delay) + if (udev->autosuspend_delay < 0 || udev->autosuspend_disabled) return -EPERM; + suspend_time = udev->last_busy + udev->autosuspend_delay; if (udev->actconfig) { for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) { intf = udev->actconfig->interface[i]; @@ -988,6 +960,24 @@ static int autosuspend_check(struct usb_device *udev) } } } + + /* If everything is okay but the device hasn't been idle for long + * enough, queue a delayed autosuspend request. + */ + if (time_after(suspend_time, jiffies)) { + if (!timer_pending(&udev->autosuspend.timer)) { + + /* The value of jiffies may change between the + * time_after() comparison above and the subtraction + * below. That's okay; the system behaves sanely + * when a timer is registered for the present moment + * or for the past. + */ + queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend, + suspend_time - jiffies); + } + return -EAGAIN; + } return 0; } @@ -1033,26 +1023,25 @@ static int autosuspend_check(struct usb_device *udev) * * This routine can run only in process context. */ -int usb_suspend_both(struct usb_device *udev, pm_message_t msg) +static int usb_suspend_both(struct usb_device *udev, pm_message_t msg) { int status = 0; int i = 0; struct usb_interface *intf; struct usb_device *parent = udev->parent; - cancel_delayed_work(&udev->autosuspend); - if (udev->state == USB_STATE_NOTATTACHED) - return 0; - if (udev->state == USB_STATE_SUSPENDED) - return 0; + if (udev->state == USB_STATE_NOTATTACHED || + udev->state == USB_STATE_SUSPENDED) + goto done; udev->do_remote_wakeup = device_may_wakeup(&udev->dev); if (udev->auto_pm) { status = autosuspend_check(udev); if (status < 0) - return status; + goto done; } + cancel_delayed_work(&udev->autosuspend); /* Suspend all the interfaces and then udev itself */ if (udev->actconfig) { @@ -1077,6 +1066,7 @@ int usb_suspend_both(struct usb_device *udev, pm_message_t msg) } else if (parent) usb_autosuspend_device(parent); + done: // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); return status; } @@ -1109,7 +1099,7 @@ int usb_suspend_both(struct usb_device *udev, pm_message_t msg) * * This routine can run only in process context. */ -int usb_resume_both(struct usb_device *udev) +static int usb_resume_both(struct usb_device *udev) { int status = 0; int i; @@ -1117,11 +1107,17 @@ int usb_resume_both(struct usb_device *udev) struct usb_device *parent = udev->parent; cancel_delayed_work(&udev->autosuspend); - if (udev->state == USB_STATE_NOTATTACHED) - return -ENODEV; + if (udev->state == USB_STATE_NOTATTACHED) { + status = -ENODEV; + goto done; + } /* Propagate the resume up the tree, if necessary */ if (udev->state == USB_STATE_SUSPENDED) { + if (udev->auto_pm && udev->autoresume_disabled) { + status = -EPERM; + goto done; + } if (parent) { status = usb_autoresume_device(parent); if (status == 0) { @@ -1167,6 +1163,7 @@ int usb_resume_both(struct usb_device *udev) } } + done: // dev_dbg(&udev->dev, "%s: status %d\n", __FUNCTION__, status); return status; } @@ -1181,20 +1178,34 @@ static int usb_autopm_do_device(struct usb_device *udev, int inc_usage_cnt) int status = 0; usb_pm_lock(udev); + udev->auto_pm = 1; udev->pm_usage_cnt += inc_usage_cnt; WARN_ON(udev->pm_usage_cnt < 0); if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) { - udev->auto_pm = 1; - status = usb_resume_both(udev); + if (udev->state == USB_STATE_SUSPENDED) + status = usb_resume_both(udev); if (status != 0) udev->pm_usage_cnt -= inc_usage_cnt; - } else if (inc_usage_cnt <= 0 && autosuspend_check(udev) == 0) - queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend, - udev->autosuspend_delay); + else if (inc_usage_cnt) + udev->last_busy = jiffies; + } else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) { + if (inc_usage_cnt) + udev->last_busy = jiffies; + status = usb_suspend_both(udev, PMSG_SUSPEND); + } usb_pm_unlock(udev); return status; } +/* usb_autosuspend_work - callback routine to autosuspend a USB device */ +void usb_autosuspend_work(struct work_struct *work) +{ + struct usb_device *udev = + container_of(work, struct usb_device, autosuspend.work); + + usb_autopm_do_device(udev, 0); +} + /** * usb_autosuspend_device - delayed autosuspend of a USB device and its interfaces * @udev: the usb_device to autosuspend @@ -1286,15 +1297,20 @@ static int usb_autopm_do_interface(struct usb_interface *intf, if (intf->condition == USB_INTERFACE_UNBOUND) status = -ENODEV; else { + udev->auto_pm = 1; intf->pm_usage_cnt += inc_usage_cnt; if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) { - udev->auto_pm = 1; - status = usb_resume_both(udev); + if (udev->state == USB_STATE_SUSPENDED) + status = usb_resume_both(udev); if (status != 0) intf->pm_usage_cnt -= inc_usage_cnt; - } else if (inc_usage_cnt <= 0 && autosuspend_check(udev) == 0) - queue_delayed_work(ksuspend_usb_wq, &udev->autosuspend, - udev->autosuspend_delay); + else if (inc_usage_cnt) + udev->last_busy = jiffies; + } else if (inc_usage_cnt <= 0 && intf->pm_usage_cnt <= 0) { + if (inc_usage_cnt) + udev->last_busy = jiffies; + status = usb_suspend_both(udev, PMSG_SUSPEND); + } } usb_pm_unlock(udev); return status; @@ -1353,11 +1369,14 @@ EXPORT_SYMBOL_GPL(usb_autopm_put_interface); * or @intf is unbound. A typical example would be a character-device * driver when its device file is opened. * - * The routine increments @intf's usage counter. So long as the counter - * is greater than 0, autosuspend will not be allowed for @intf or its - * usb_device. When the driver is finished using @intf it should call - * usb_autopm_put_interface() to decrement the usage counter and queue - * a delayed autosuspend request (if the counter is <= 0). + * + * The routine increments @intf's usage counter. (However if the + * autoresume fails then the counter is re-decremented.) So long as the + * counter is greater than 0, autosuspend will not be allowed for @intf + * or its usb_device. When the driver is finished using @intf it should + * call usb_autopm_put_interface() to decrement the usage counter and + * queue a delayed autosuspend request (if the counter is <= 0). + * * * Note that @intf->pm_usage_cnt is owned by the interface driver. The * core will not change its value other than the increment and decrement @@ -1405,50 +1424,96 @@ int usb_autopm_set_interface(struct usb_interface *intf) } EXPORT_SYMBOL_GPL(usb_autopm_set_interface); +#else + +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) +{ + struct usb_device *udev; + + if (!is_usb_device(dev)) /* Ignore PM for interfaces */ + return 0; + udev = to_usb_device(dev); + if (udev->autoresume_disabled) + return -EPERM; + return usb_external_resume_device(udev); +} + +#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 }; |