USB: Enhance usage of pm_message_t

This patch (as1177) modifies the USB core suspend and resume
routines. The resume functions now will take a pm_message_t argument,
so they will know what sort of resume is occurring. The new argument
is also passed to the port suspend/resume and bus suspend/resume
routines (although they don't use it for anything but debugging).

In addition, special pm_message_t values are used for user-initiated,
device-initiated (i.e., remote wakeup), and automatic suspend/resume.
By testing these values, drivers can tell whether or not a particular
suspend was an autosuspend. Unfortunately, they can't do the same for
resumes -- not until the pm_message_t argument is also passed to the
drivers' resume methods. That will require a bigger change.

IMO, the whole Power Management framework should have been set up this
way in the first place.

Signed-off-by: Alan Stern <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/usb/class/cdc-acm.c

···
 	struct acm *acm = usb_get_intfdata(intf);
 	int cnt;
 
-	if (acm->dev->auto_pm) {
+	if (message.event & PM_EVENT_AUTO) {
 		int b;
 
 		spin_lock_irq(&acm->read_lock);

drivers/usb/class/cdc-wdm.c

···
 
 	mutex_lock(&desc->plock);
 #ifdef CONFIG_PM
-	if (interface_to_usbdev(desc->intf)->auto_pm && test_bit(WDM_IN_USE, &desc->flags)) {
+	if ((message.event & PM_EVENT_AUTO) &&
+			test_bit(WDM_IN_USE, &desc->flags)) {
 		rv = -EBUSY;
 	} else {
 #endif

drivers/usb/core/driver.c

···
 }
 
 /* Caller has locked udev's pm_mutex */
-static int usb_resume_device(struct usb_device *udev)
+static int usb_resume_device(struct usb_device *udev, pm_message_t msg)
 {
 	struct usb_device_driver	*udriver;
 	int				status = 0;
···
 		udev->reset_resume = 1;
 
 	udriver = to_usb_device_driver(udev->dev.driver);
-	status = udriver->resume(udev);
+	status = udriver->resume(udev, msg);
 
  done:
 	dev_vdbg(&udev->dev, "%s: status %d\n", __func__, status);
···
 		status = driver->suspend(intf, msg);
 		if (status == 0)
 			mark_quiesced(intf);
-		else if (!udev->auto_pm)
+		else if (!(msg.event & PM_EVENT_AUTO))
 			dev_err(&intf->dev, "%s error %d\n",
 					"suspend", status);
 	} else {
···
 
 /* Caller has locked intf's usb_device's pm_mutex */
 static int usb_resume_interface(struct usb_device *udev,
-		struct usb_interface *intf, int reset_resume)
+		struct usb_interface *intf, pm_message_t msg, int reset_resume)
 {
 	struct usb_driver	*driver;
 	int			status = 0;
···
  * all the interfaces which were suspended are resumed so that they remain
  * in the same state as the device.
  *
- * If an autosuspend is in progress (@udev->auto_pm is set), the routine
- * checks first to make sure that neither the device itself or any of its
- * active interfaces is in use (pm_usage_cnt is greater than 0).  If they
- * are, the autosuspend fails.
+ * If an autosuspend is in progress the routine checks first to make sure
+ * that neither the device itself or any of its active interfaces is in use
+ * (pm_usage_cnt is greater than 0).  If they are, the autosuspend fails.
  *
  * If the suspend succeeds, the routine recursively queues an autosuspend
  * request for @udev's parent device, thereby propagating the change up
···
 
 	udev->do_remote_wakeup = device_may_wakeup(&udev->dev);
 
-	if (udev->auto_pm) {
+	if (msg.event & PM_EVENT_AUTO) {
 		status = autosuspend_check(udev, 0);
 		if (status < 0)
 			goto done;
···
 
 	/* If the suspend failed, resume interfaces that did get suspended */
 	if (status != 0) {
+		pm_message_t msg2;
+
+		msg2.event = msg.event ^ (PM_EVENT_SUSPEND | PM_EVENT_RESUME);
 		while (--i >= 0) {
 			intf = udev->actconfig->interface[i];
-			usb_resume_interface(udev, intf, 0);
+			usb_resume_interface(udev, intf, msg2, 0);
 		}
 
 		/* Try another autosuspend when the interfaces aren't busy */
-		if (udev->auto_pm)
+		if (msg.event & PM_EVENT_AUTO)
 			autosuspend_check(udev, status == -EBUSY);
 
 	/* If the suspend succeeded then prevent any more URB submissions,
···
 /**
  * usb_resume_both - resume a USB device and its interfaces
  * @udev: the usb_device to resume
+ * @msg: Power Management message describing this state transition
  *
  * This is the central routine for resuming USB devices.  It calls the
  * the resume method for @udev and then calls the resume methods for all
···
  *
  * This routine can run only in process context.
  */
-static int usb_resume_both(struct usb_device *udev)
+static int usb_resume_both(struct usb_device *udev, pm_message_t msg)
 {
 	int			status = 0;
 	int			i;
···
 
 	/* Propagate the resume up the tree, if necessary */
 	if (udev->state == USB_STATE_SUSPENDED) {
-		if (udev->auto_pm && udev->autoresume_disabled) {
+		if ((msg.event & PM_EVENT_AUTO) &&
+				udev->autoresume_disabled) {
 			status = -EPERM;
 			goto done;
 		}
 		if (parent) {
 			status = usb_autoresume_device(parent);
 			if (status == 0) {
-				status = usb_resume_device(udev);
+				status = usb_resume_device(udev, msg);
 				if (status || udev->state ==
 						USB_STATE_NOTATTACHED) {
 					usb_autosuspend_device(parent);
···
 			/* We can't progagate beyond the USB subsystem,
 			 * so if a root hub's controller is suspended
 			 * then we're stuck. */
-			status = usb_resume_device(udev);
+			status = usb_resume_device(udev, msg);
 		}
 	} else if (udev->reset_resume)
-		status = usb_resume_device(udev);
+		status = usb_resume_device(udev, msg);
 
 	if (status == 0 && udev->actconfig) {
 		for (i = 0; i < udev->actconfig->desc.bNumInterfaces; i++) {
 			intf = udev->actconfig->interface[i];
-			usb_resume_interface(udev, intf, udev->reset_resume);
+			usb_resume_interface(udev, intf, msg,
+					udev->reset_resume);
 		}
 	}
 
···
 		udev->last_busy = jiffies;
 	if (inc_usage_cnt >= 0 && udev->pm_usage_cnt > 0) {
 		if (udev->state == USB_STATE_SUSPENDED)
-			status = usb_resume_both(udev);
+			status = usb_resume_both(udev, PMSG_AUTO_RESUME);
 		if (status != 0)
 			udev->pm_usage_cnt -= inc_usage_cnt;
 		else if (inc_usage_cnt)
 			udev->last_busy = jiffies;
 	} else if (inc_usage_cnt <= 0 && udev->pm_usage_cnt <= 0) {
-		status = usb_suspend_both(udev, PMSG_SUSPEND);
+		status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
 	}
 	usb_pm_unlock(udev);
 	return status;
···
 		udev->last_busy = jiffies;
 		if (inc_usage_cnt >= 0 && intf->pm_usage_cnt > 0) {
 			if (udev->state == USB_STATE_SUSPENDED)
-				status = usb_resume_both(udev);
+				status = usb_resume_both(udev,
+						PMSG_AUTO_RESUME);
 			if (status != 0)
 				intf->pm_usage_cnt -= inc_usage_cnt;
 			else
 				udev->last_busy = jiffies;
 		} else if (inc_usage_cnt <= 0 && intf->pm_usage_cnt <= 0) {
-			status = usb_suspend_both(udev, PMSG_SUSPEND);
+			status = usb_suspend_both(udev, PMSG_AUTO_SUSPEND);
 		}
 	}
 	usb_pm_unlock(udev);
···
 /**
  * usb_external_resume_device - external resume of a USB device and its interfaces
  * @udev: the usb_device to resume
+ * @msg: Power Management message describing this state transition
  *
  * This routine handles external resume requests: ones not generated
  * internally by a USB driver (autoresume) but rather coming from the user
···
  *
  * The caller must hold @udev's device lock.
  */
-int usb_external_resume_device(struct usb_device *udev)
+int usb_external_resume_device(struct usb_device *udev, pm_message_t msg)
 {
 	int	status;
 
 	usb_pm_lock(udev);
 	udev->auto_pm = 0;
-	status = usb_resume_both(udev);
+	status = usb_resume_both(udev, msg);
 	udev->last_busy = jiffies;
 	usb_pm_unlock(udev);
 	if (status == 0)
···
 	return status;
 }
 
-int usb_suspend(struct device *dev, pm_message_t message)
+int usb_suspend(struct device *dev, pm_message_t msg)
 {
 	struct usb_device	*udev;
 
···
 	}
 
 	udev->skip_sys_resume = 0;
-	return usb_external_suspend_device(udev, message);
+	return usb_external_suspend_device(udev, msg);
 }
 
-int usb_resume(struct device *dev)
+int usb_resume(struct device *dev, pm_message_t msg)
 {
 	struct usb_device	*udev;
 
···
 	 */
 	if (udev->skip_sys_resume)
 		return 0;
-	return usb_external_resume_device(udev);
+	return usb_external_resume_device(udev, msg);
 }
 
 #endif /* CONFIG_PM */

drivers/usb/core/generic.c

···
 	 * interfaces manually by doing a bus (or "global") suspend.
 	 */
 	if (!udev->parent)
-		rc = hcd_bus_suspend(udev);
+		rc = hcd_bus_suspend(udev, msg);
 
 	/* Non-root devices don't need to do anything for FREEZE or PRETHAW */
 	else if (msg.event == PM_EVENT_FREEZE || msg.event == PM_EVENT_PRETHAW)
 		rc = 0;
 	else
-		rc = usb_port_suspend(udev);
+		rc = usb_port_suspend(udev, msg);
 
 	return rc;
 }
 
-static int generic_resume(struct usb_device *udev)
+static int generic_resume(struct usb_device *udev, pm_message_t msg)
 {
 	int rc;
 
···
 	 * interfaces manually by doing a bus (or "global") resume.
 	 */
 	if (!udev->parent)
-		rc = hcd_bus_resume(udev);
+		rc = hcd_bus_resume(udev, msg);
 	else
-		rc = usb_port_resume(udev);
+		rc = usb_port_resume(udev, msg);
 	return rc;
 }
 

drivers/usb/core/hcd.c

···
 
 #ifdef	CONFIG_PM
 
-int hcd_bus_suspend(struct usb_device *rhdev)
+int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
 {
 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
 	int		status;
 	int		old_state = hcd->state;
 
 	dev_dbg(&rhdev->dev, "bus %s%s\n",
-			rhdev->auto_pm ? "auto-" : "", "suspend");
+			(msg.event & PM_EVENT_AUTO ? "auto-" : ""), "suspend");
 	if (!hcd->driver->bus_suspend) {
 		status = -ENOENT;
 	} else {
···
 	return status;
 }
 
-int hcd_bus_resume(struct usb_device *rhdev)
+int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
 {
 	struct usb_hcd	*hcd = container_of(rhdev->bus, struct usb_hcd, self);
 	int		status;
 	int		old_state = hcd->state;
 
 	dev_dbg(&rhdev->dev, "usb %s%s\n",
-			rhdev->auto_pm ? "auto-" : "", "resume");
+			(msg.event & PM_EVENT_AUTO ? "auto-" : ""), "resume");
 	if (!hcd->driver->bus_resume)
 		return -ENOENT;
 	if (hcd->state == HC_STATE_RUNNING)
···
 
 	usb_lock_device(udev);
 	usb_mark_last_busy(udev);
-	usb_external_resume_device(udev);
+	usb_external_resume_device(udev, PMSG_REMOTE_RESUME);
 	usb_unlock_device(udev);
 }
 

drivers/usb/core/hcd.h

···
 #ifdef CONFIG_PM
 extern void usb_hcd_resume_root_hub(struct usb_hcd *hcd);
 extern void usb_root_hub_lost_power(struct usb_device *rhdev);
-extern int hcd_bus_suspend(struct usb_device *rhdev);
-extern int hcd_bus_resume(struct usb_device *rhdev);
+extern int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg);
+extern int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg);
 #else
 static inline void usb_hcd_resume_root_hub(struct usb_hcd *hcd)
 {

drivers/usb/core/hub.c

···
  *
  * Returns 0 on success, else negative errno.
  */
-int usb_port_suspend(struct usb_device *udev)
+int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 {
 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
 	int		port1 = udev->portnum;
···
 	} else {
 		/* device has up to 10 msec to fully suspend */
 		dev_dbg(&udev->dev, "usb %ssuspend\n",
-				udev->auto_pm ? "auto-" : "");
+				(msg.event & PM_EVENT_AUTO ? "auto-" : ""));
 		usb_set_device_state(udev, USB_STATE_SUSPENDED);
 		msleep(10);
 	}
···
  *
  * Returns 0 on success, else negative errno.
  */
-int usb_port_resume(struct usb_device *udev)
+int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 {
 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
 	int		port1 = udev->portnum;
···
 	} else {
 		/* drive resume for at least 20 msec */
 		dev_dbg(&udev->dev, "usb %sresume\n",
-				udev->auto_pm ? "auto-" : "");
+				(msg.event & PM_EVENT_AUTO ? "auto-" : ""));
 		msleep(25);
 
 		/* Virtual root hubs can trigger on GET_PORT_STATUS to
···
 	if (udev->state == USB_STATE_SUSPENDED) {
 		dev_dbg(&udev->dev, "usb %sresume\n", "wakeup-");
 		usb_mark_last_busy(udev);
-		status = usb_external_resume_device(udev);
+		status = usb_external_resume_device(udev, PMSG_REMOTE_RESUME);
 	}
 	return status;
 }
···
 
 /* When CONFIG_USB_SUSPEND isn't set, we never suspend or resume any ports. */
 
-int usb_port_suspend(struct usb_device *udev)
+int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 {
 	return 0;
 }
 
 /* However we may need to do a reset-resume */
 
-int usb_port_resume(struct usb_device *udev)
+int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 {
 	struct usb_hub	*hub = hdev_to_hub(udev->parent);
 	int		port1 = udev->portnum;
···
 
 		udev = hdev->children [port1-1];
 		if (udev && udev->can_submit) {
-			if (!hdev->auto_pm)
+			if (!(msg.event & PM_EVENT_AUTO))
 				dev_dbg(&intf->dev, "port %d nyet suspended\n",
 						port1);
 			return -EBUSY;

drivers/usb/core/sysfs.c

···
 			strncmp(buf, on_string, len) == 0) {
 		udev->autosuspend_disabled = 1;
 		udev->autoresume_disabled = 0;
-		rc = usb_external_resume_device(udev);
+		rc = usb_external_resume_device(udev, PMSG_USER_RESUME);
 
 	} else if (len == sizeof auto_string - 1 &&
 			strncmp(buf, auto_string, len) == 0) {
 		udev->autosuspend_disabled = 0;
 		udev->autoresume_disabled = 0;
-		rc = usb_external_resume_device(udev);
+		rc = usb_external_resume_device(udev, PMSG_USER_RESUME);
 
 	} else if (len == sizeof suspend_string - 1 &&
 			strncmp(buf, suspend_string, len) == 0) {
 		udev->autosuspend_disabled = 0;
 		udev->autoresume_disabled = 1;
-		rc = usb_external_suspend_device(udev, PMSG_SUSPEND);
+		rc = usb_external_suspend_device(udev, PMSG_USER_SUSPEND);
 
 	} else
 		rc = -EINVAL;

drivers/usb/core/usb.c

···
 static void usb_dev_complete(struct device *dev)
 {
 	/* Currently used only for rebinding interfaces */
-	usb_resume(dev);	/* Implement eventually? */
+	usb_resume(dev, PMSG_RESUME);	/* Message event is meaningless */
 }
 
 static int usb_dev_suspend(struct device *dev)
···
 
 static int usb_dev_resume(struct device *dev)
 {
-	return usb_resume(dev);
+	return usb_resume(dev, PMSG_RESUME);
 }
 
 static int usb_dev_freeze(struct device *dev)
···
 
 static int usb_dev_thaw(struct device *dev)
 {
-	return usb_resume(dev);
+	return usb_resume(dev, PMSG_THAW);
 }
 
 static int usb_dev_poweroff(struct device *dev)
···
 
 static int usb_dev_restore(struct device *dev)
 {
-	return usb_resume(dev);
+	return usb_resume(dev, PMSG_RESTORE);
 }
 
 static struct dev_pm_ops usb_device_pm_ops = {

drivers/usb/core/usb.h

···
+#include <linux/pm.h>
+
 /* Functions local to drivers/usb/core/ */
 
 extern int usb_create_sysfs_dev_files(struct usb_device *dev);
···
 #ifdef	CONFIG_PM
 
 extern int usb_suspend(struct device *dev, pm_message_t msg);
-extern int usb_resume(struct device *dev);
+extern int usb_resume(struct device *dev, pm_message_t msg);
 
 extern void usb_autosuspend_work(struct work_struct *work);
 extern void usb_autoresume_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_port_suspend(struct usb_device *dev, pm_message_t msg);
+extern int usb_port_resume(struct usb_device *dev, pm_message_t msg);
 extern int usb_external_suspend_device(struct usb_device *udev,
 		pm_message_t msg);
-extern int usb_external_resume_device(struct usb_device *udev);
+extern int usb_external_resume_device(struct usb_device *udev,
+		pm_message_t msg);
 
 static inline void usb_pm_lock(struct usb_device *udev)
 {
···
 
 #else
 
-static inline int usb_port_suspend(struct usb_device *udev)
+static inline int usb_port_suspend(struct usb_device *udev, pm_message_t msg)
 {
 	return 0;
 }
 
-static inline int usb_port_resume(struct usb_device *udev)
+static inline int usb_port_resume(struct usb_device *udev, pm_message_t msg)
 {
 	return 0;
 }

include/linux/usb.h

···
 	void (*disconnect) (struct usb_device *udev);
 
 	int (*suspend) (struct usb_device *udev, pm_message_t message);
-	int (*resume) (struct usb_device *udev);
+	int (*resume) (struct usb_device *udev, pm_message_t message);
 	struct usbdrv_wrap drvwrap;
 	unsigned int supports_autosuspend:1;
 };