3 files changed, 41 insertions, 7 deletions

diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index f7efe025beda..aefc3496376a 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -152,7 +152,7 @@ static const struct hc_driver xhci_pci_hc_driver = {
         .reset_bandwidth =      xhci_reset_bandwidth,
         .address_device =       xhci_address_device,
         .update_hub_device =    xhci_update_hub_device,
-        .reset_device =         xhci_reset_device,
+        .reset_device =         xhci_discover_or_reset_device,
 
         /*
          * scheduling support
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 0bec04070334..7928af5c91cb 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -1943,8 +1943,13 @@ int xhci_free_streams(struct usb_hcd *hcd, struct usb_device *udev,
  * Wait for the Reset Device command to finish.  Remove all structures
  * associated with the endpoints that were disabled.  Clear the input device
  * structure?  Cache the rings?  Reset the control endpoint 0 max packet size?
+ *
+ * If the virt_dev to be reset does not exist or does not match the udev,
+ * it means the device is lost, possibly due to the xHC restore error and
+ * re-initialization during S3/S4. In this case, call xhci_alloc_dev() to
+ * re-allocate the device.
  */
-int xhci_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
+int xhci_discover_or_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
 {
         int ret, i;
         unsigned long flags;
@@ -1955,12 +1960,36 @@ int xhci_reset_device(struct usb_hcd *hcd, struct usb_device *udev)
         int timeleft;
         int last_freed_endpoint;
 
-        ret = xhci_check_args(hcd, udev, NULL, 0, true, __func__);
+        ret = xhci_check_args(hcd, udev, NULL, 0, false, __func__);
         if (ret <= 0)
                 return ret;
         xhci = hcd_to_xhci(hcd);
         slot_id = udev->slot_id;
         virt_dev = xhci->devs[slot_id];
+        if (!virt_dev) {
+                xhci_dbg(xhci, "The device to be reset with slot ID %u does "
+                                "not exist. Re-allocate the device\n", slot_id);
+                ret = xhci_alloc_dev(hcd, udev);
+                if (ret == 1)
+                        return 0;
+                else
+                        return -EINVAL;
+        }
+
+        if (virt_dev->udev != udev) {
+                /* If the virt_dev and the udev does not match, this virt_dev
+                 * may belong to another udev.
+                 * Re-allocate the device.
+                 */
+                xhci_dbg(xhci, "The device to be reset with slot ID %u does "
+                                "not match the udev. Re-allocate the device\n",
+                                slot_id);
+                ret = xhci_alloc_dev(hcd, udev);
+                if (ret == 1)
+                        return 0;
+                else
+                        return -EINVAL;
+        }
 
         xhci_dbg(xhci, "Resetting device with slot ID %u\n", slot_id);
         /* Allocate the command structure that holds the struct completion.
@@ -2176,12 +2205,17 @@ int xhci_address_device(struct usb_hcd *hcd, struct usb_device *udev)
 
         virt_dev = xhci->devs[udev->slot_id];
 
-        /* If this is a Set Address to an unconfigured device, setup ep 0 */
-        if (!udev->config)
+        slot_ctx = xhci_get_slot_ctx(xhci, virt_dev->in_ctx);
+        /*
+         * If this is the first Set Address since device plug-in or
+         * virt_device realloaction after a resume with an xHCI power loss,
+         * then set up the slot context.
+         */
+        if (!slot_ctx->dev_info)
                 xhci_setup_addressable_virt_dev(xhci, udev);
+        /* Otherwise, update the control endpoint ring enqueue pointer. */
         else
                 xhci_copy_ep0_dequeue_into_input_ctx(xhci, udev);
-        /* Otherwise, assume the core has the device configured how it wants */
         xhci_dbg(xhci, "Slot ID %d Input Context:\n", udev->slot_id);
         xhci_dbg_ctx(xhci, virt_dev->in_ctx, 2);
 
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index f03f140a7d9a..490409f918f2 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1389,7 +1389,7 @@ int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status);
 int xhci_add_endpoint(struct usb_hcd *hcd, struct usb_device *udev, struct usb_host_endpoint *ep);
 int xhci_drop_endpoint(struct usb_hcd *hcd, struct usb_device *udev, struct usb_host_endpoint *ep);
 void xhci_endpoint_reset(struct usb_hcd *hcd, struct usb_host_endpoint *ep);
-int xhci_reset_device(struct usb_hcd *hcd, struct usb_device *udev);
+int xhci_discover_or_reset_device(struct usb_hcd *hcd, struct usb_device *udev);
 int xhci_check_bandwidth(struct usb_hcd *hcd, struct usb_device *udev);
 void xhci_reset_bandwidth(struct usb_hcd *hcd, struct usb_device *udev);