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>

5 files changed, 16 insertions, 12 deletions

diff --git a/drivers/usb/core/driver.c b/drivers/usb/core/driver.c
index ca43a6f824ab..ba5bbc7eedcc 100644
--- a/drivers/usb/core/driver.c
+++ b/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) {
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index e5874e8b8cbc..2c79aa6ca2b4 100644
--- a/drivers/usb/core/hcd.c
+++ b/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.
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index bd08d51d7f41..691acf2223c2 100644
--- a/drivers/usb/core/hub.c
+++ b/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);
diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 76db76fdb4ec..c20c03aaf012 100644
--- a/drivers/usb/core/urb.c
+++ b/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
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index e5ff161776fa..8121edbd1494 100644
--- a/drivers/usb/core/usb.c
+++ b/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