diff options
Diffstat (limited to 'drivers/usb/core')
| -rw-r--r-- | drivers/usb/core/hub.c | 34 | ||||
| -rw-r--r-- | drivers/usb/core/usb.c | 23 |
2 files changed, 42 insertions, 15 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index d3337d9c31d..33127b828d6 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -1323,11 +1323,9 @@ int usb_new_device(struct usb_device *udev) * (Includes HNP test device.) */ if (udev->bus->b_hnp_enable || udev->bus->is_b_host) { - static int __usb_suspend_device (struct usb_device *, - int port1, pm_message_t state); - err = __usb_suspend_device(udev, - udev->bus->otg_port, - PMSG_SUSPEND); + static int __usb_suspend_device(struct usb_device *, + int port1); + err = __usb_suspend_device(udev, udev->bus->otg_port); if (err < 0) dev_dbg(&udev->dev, "HNP fail, %d\n", err); } @@ -1517,7 +1515,7 @@ static void hub_port_logical_disconnect(struct usb_hub *hub, int port1) /* FIXME let caller ask to power down the port: * - some devices won't enumerate without a VBUS power cycle * - SRP saves power that way - * - usb_suspend_device(dev, PMSG_SUSPEND) + * - ... new call, TBD ... * That's easy if this hub can switch power per-port, and * khubd reactivates the port later (timer, SRP, etc). * Powerdown must be optional, because of reset/DFU. @@ -1599,9 +1597,12 @@ static int hub_port_suspend(struct usb_hub *hub, int port1, * Other than re-initializing the hub (plug/unplug, except for root hubs), * Linux (2.6) currently has NO mechanisms to initiate that: no khubd * timer, no SRP, no requests through sysfs. + * + * If CONFIG_USB_SUSPEND isn't enabled, devices only really suspend when + * the root hub for their bus goes into global suspend ... so we don't + * (falsely) update the device power state to say it suspended. */ -static int __usb_suspend_device (struct usb_device *udev, int port1, - pm_message_t state) +static int __usb_suspend_device (struct usb_device *udev, int port1) { int status; @@ -1648,14 +1649,13 @@ static int __usb_suspend_device (struct usb_device *udev, int port1, udev); if (status == 0) - udev->dev.power.power_state = state; + udev->dev.power.power_state = PMSG_SUSPEND; return status; } /** * usb_suspend_device - suspend a usb device * @udev: device that's no longer in active use - * @state: PMSG_SUSPEND to suspend * Context: must be able to sleep; device not locked * * Suspends a USB device that isn't in active use, conserving power. @@ -1664,13 +1664,16 @@ static int __usb_suspend_device (struct usb_device *udev, int port1, * suspend by the host, using usb_resume_device(). It's also routine * to disconnect devices while they are suspended. * + * This only affects the USB hardware for a device; its interfaces + * (and, for hubs, child devices) must already have been suspended. + * * Suspending OTG devices may trigger HNP, if that's been enabled * between a pair of dual-role devices. That will change roles, such * as from A-Host to A-Peripheral or from B-Host back to B-Peripheral. * * Returns 0 on success, else negative errno. */ -int usb_suspend_device(struct usb_device *udev, pm_message_t state) +int usb_suspend_device(struct usb_device *udev) { int port1, status; @@ -1678,12 +1681,15 @@ int usb_suspend_device(struct usb_device *udev, pm_message_t state) if (port1 < 0) return port1; - status = __usb_suspend_device(udev, port1, state); + status = __usb_suspend_device(udev, port1); usb_unlock_device(udev); return status; } /* + * If the USB "suspend" state is in use (rather than "global suspend"), + * many devices will be individually taken out of suspend state using + * special" resume" signaling. These routines kick in shortly after * hardware resume signaling is finished, either because of selective * resume (by host) or remote wakeup (by device) ... now see what changed * in the tree that's rooted at this device. @@ -1986,13 +1992,15 @@ void usb_resume_root_hub(struct usb_device *hdev) #else /* !CONFIG_USB_SUSPEND */ -int usb_suspend_device(struct usb_device *udev, pm_message_t state) +int usb_suspend_device(struct usb_device *udev) { + /* state does NOT lie by saying it's USB_STATE_SUSPENDED! */ return 0; } int usb_resume_device(struct usb_device *udev) { + udev->dev.power_state.event = PM_EVENT_ON; return 0; } diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c index 6ecfdce4f84..e89dbd43e95 100644 --- a/drivers/usb/core/usb.c +++ b/drivers/usb/core/usb.c @@ -1414,14 +1414,33 @@ void usb_buffer_unmap_sg (struct usb_device *dev, unsigned pipe, usb_pipein (pipe) ? DMA_FROM_DEVICE : DMA_TO_DEVICE); } +static int verify_suspended(struct device *dev, void *unused) +{ + return (dev->power.power_state.event == PM_EVENT_ON) ? -EBUSY : 0; +} + static int usb_generic_suspend(struct device *dev, pm_message_t message) { struct usb_interface *intf; struct usb_driver *driver; int status; - if (dev->driver == &usb_generic_driver) - return usb_suspend_device (to_usb_device(dev), message); + /* USB devices enter SUSPEND state through their hubs, but can be + * marked for FREEZE as soon as their children are already idled. + */ + if (dev->driver == &usb_generic_driver) { + if (dev->power.power_state.event == message.event) + return 0; + /* we need to rule out bogus requests through sysfs */ + status = device_for_each_child(dev, NULL, verify_suspended); + if (status) + return status; + if (message.event == PM_EVENT_FREEZE) { + dev->power.power_state = message; + return 0; + } + return usb_suspend_device (to_usb_device(dev)); + } if ((dev->driver == NULL) || (dev->driver_data == &usb_generic_driver_data)) |