USB: flush outstanding URBs when suspending

This patch (as989) makes usbcore flush all outstanding URBs for each
device as the device is suspended.  This will be true even when
CONFIG_USB_SUSPEND is not enabled.

In addition, an extra can_submit flag is added to the usb_device
structure.  That flag will be turned off whenever a suspend request
has been received for the device, even if the device isn't actually
suspended because CONFIG_USB_SUSPEND isn't set.

It's no longer necessary to check for the device state being equal to
USB_STATE_SUSPENDED during URB submission; that check can be replaced
by a check of the can_submit flag.  This also permits us to remove
some questionable references to the deprecated power.power_state field.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/driver.c

@@ -1102,9 +1102,16 @@ static int usb_suspend_both(struct usb_device *udev, pm_message_t msg)
 		if (udev->auto_pm)
 			autosuspend_check(udev);
 
-	/* If the suspend succeeded, propagate it up the tree */
+	/* If the suspend succeeded then prevent any more URB submissions,
+	 * flush any outstanding URBs, and propagate the suspend up the tree.
+	 */
 	} else {
 		cancel_delayed_work(&udev->autosuspend);
+		udev->can_submit = 0;
+		for (i = 0; i < 16; ++i) {
+			usb_hcd_flush_endpoint(udev, udev->ep_out[i]);
+			usb_hcd_flush_endpoint(udev, udev->ep_in[i]);
+		}
 		if (parent)
 			usb_autosuspend_device(parent);
 	}
@@ -1154,6 +1161,7 @@ static int usb_resume_both(struct usb_device *udev)
 		status = -ENODEV;
 		goto done;
 	}
+	udev->can_submit = 1;
 
 	/* Propagate the resume up the tree, if necessary */
 	if (udev->state == USB_STATE_SUSPENDED) {

drivers/usb/core/hcd.c

@@ -1014,6 +1014,11 @@ int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
 		goto done;
 	}
 
+	if (unlikely(!urb->dev->can_submit)) {
+		rc = -EHOSTUNREACH;
+		goto done;
+	}
+
 	/*
 	 * Check the host controller's state and add the URB to the
 	 * endpoint's queue.

drivers/usb/core/hub.c

@@ -1955,14 +1955,7 @@ static int hub_suspend(struct usb_interface *intf, pm_message_t msg)
 		struct usb_device	*udev;
 
 		udev = hdev->children [port1-1];
-		if (udev && msg.event == PM_EVENT_SUSPEND &&
-#ifdef	CONFIG_USB_SUSPEND
-				udev->state != USB_STATE_SUSPENDED
-#else
-				udev->dev.power.power_state.event
-					== PM_EVENT_ON
-#endif
-				) {
+		if (udev && udev->can_submit) {
 			if (!hdev->auto_pm)
 				dev_dbg(&intf->dev, "port %d nyet suspended\n",
 						port1);

drivers/usb/core/urb.c

@@ -286,9 +286,6 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
 		return -EINVAL;
 	if (!(dev = urb->dev) || dev->state < USB_STATE_DEFAULT)
 		return -ENODEV;
-	if (dev->bus->controller->power.power_state.event != PM_EVENT_ON
-			|| dev->state == USB_STATE_SUSPENDED)
-		return -EHOSTUNREACH;
 
 	/* For now, get the endpoint from the pipe.  Eventually drivers
 	 * will be required to set urb->ep directly and we will eliminate

drivers/usb/core/usb.c

@@ -272,6 +272,7 @@ usb_alloc_dev(struct usb_device *parent, struct usb_bus *bus, unsigned port1)
 	dev->ep0.desc.bDescriptorType = USB_DT_ENDPOINT;
 	/* ep0 maxpacket comes later, from device descriptor */
 	usb_enable_endpoint(dev, &dev->ep0);
+	dev->can_submit = 1;
 
 	/* Save readable and stable topology id, distinguishing devices
 	 * by location for diagnostics, tools, driver model, etc.  The

include/linux/usb.h

@@ -383,6 +383,7 @@ struct usb_device {
 	u8 portnum;			/* Parent port number (origin 1) */
 	u8 level;			/* Number of USB hub ancestors */
 
+	unsigned can_submit:1;		/* URBs may be submitted */
 	unsigned discon_suspended:1;	/* Disconnected while suspended */
 	unsigned have_langid:1;		/* whether string_langid is valid */
 	unsigned authorized:1;		/* Policy has determined we can use it */