1 files changed, 37 insertions, 13 deletions

diff --git a/include/linux/usb.h b/include/linux/usb.h
index 10278d18709c..689b14b26c8d 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -482,6 +482,7 @@ struct usb3_lpm_parameters {
  * @connect_time: time device was first connected
  * @do_remote_wakeup:  remote wakeup should be enabled
  * @reset_resume: needs reset instead of resume
+ * @port_is_suspended: the upstream port is suspended (L2 or U3)
  * @wusb_dev: if this is a Wireless USB device, link to the WUSB
  *      specific data for the device.
  * @slot_id: Slot ID assigned by xHCI
@@ -560,6 +561,7 @@ struct usb_device {
 
         unsigned do_remote_wakeup:1;
         unsigned reset_resume:1;
+        unsigned port_is_suspended:1;
 #endif
         struct wusb_dev *wusb_dev;
         int slot_id;
@@ -588,8 +590,9 @@ extern struct usb_device *usb_hub_find_child(struct usb_device *hdev,
  */
 #define usb_hub_for_each_child(hdev, port1, child) \
         for (port1 = 1, child = usb_hub_find_child(hdev, port1); \
-                port1 <= hdev->maxchild; \
-                child = usb_hub_find_child(hdev, ++port1))
+                        port1 <= hdev->maxchild; \
+                        child = usb_hub_find_child(hdev, ++port1)) \
+                if (!child) continue; else
 
 /* USB device locking */
 #define usb_lock_device(udev)           device_lock(&(udev)->dev)
@@ -805,6 +808,22 @@ static inline int usb_make_path(struct usb_device *dev, char *buf, size_t size)
         .bcdDevice_hi = (hi)
 
 /**
+ * USB_DEVICE_INTERFACE_CLASS - describe a usb device with a specific interface class
+ * @vend: the 16 bit USB Vendor ID
+ * @prod: the 16 bit USB Product ID
+ * @cl: bInterfaceClass value
+ *
+ * This macro is used to create a struct usb_device_id that matches a
+ * specific interface class of devices.
+ */
+#define USB_DEVICE_INTERFACE_CLASS(vend, prod, cl) \
+        .match_flags = USB_DEVICE_ID_MATCH_DEVICE | \
+                       USB_DEVICE_ID_MATCH_INT_CLASS, \
+        .idVendor = (vend), \
+        .idProduct = (prod), \
+        .bInterfaceClass = (cl)
+
+/**
  * USB_DEVICE_INTERFACE_PROTOCOL - describe a usb device with a specific interface protocol
  * @vend: the 16 bit USB Vendor ID
  * @prod: the 16 bit USB Product ID
@@ -1129,8 +1148,8 @@ extern int usb_disabled(void);
  * Note: URB_DIR_IN/OUT is automatically set in usb_submit_urb().
  */
 #define URB_SHORT_NOT_OK        0x0001  /* report short reads as errors */
-#define URB_ISO_ASAP            0x0002  /* iso-only, urb->start_frame
-                                         * ignored */
+#define URB_ISO_ASAP            0x0002  /* iso-only; use the first unexpired
+                                         * slot in the schedule */
 #define URB_NO_TRANSFER_DMA_MAP 0x0004  /* urb->transfer_dma valid on submit */
 #define URB_NO_FSBR             0x0020  /* UHCI-specific */
 #define URB_ZERO_PACKET         0x0040  /* Finish bulk OUT with short packet */
@@ -1309,15 +1328,20 @@ typedef void (*usb_complete_t)(struct urb *);
  * the transfer interval in the endpoint descriptor is logarithmic.
  * Device drivers must convert that value to linear units themselves.)
  *
- * Isochronous URBs normally use the URB_ISO_ASAP transfer flag, telling
- * the host controller to schedule the transfer as soon as bandwidth
- * utilization allows, and then set start_frame to reflect the actual frame
- * selected during submission.  Otherwise drivers must specify the start_frame
- * and handle the case where the transfer can't begin then.  However, drivers
- * won't know how bandwidth is currently allocated, and while they can
- * find the current frame using usb_get_current_frame_number () they can't
- * know the range for that frame number.  (Ranges for frame counter values
- * are HC-specific, and can go from 256 to 65536 frames from "now".)
+ * If an isochronous endpoint queue isn't already running, the host
+ * controller will schedule a new URB to start as soon as bandwidth
+ * utilization allows.  If the queue is running then a new URB will be
+ * scheduled to start in the first transfer slot following the end of the
+ * preceding URB, if that slot has not already expired.  If the slot has
+ * expired (which can happen when IRQ delivery is delayed for a long time),
+ * the scheduling behavior depends on the URB_ISO_ASAP flag.  If the flag
+ * is clear then the URB will be scheduled to start in the expired slot,
+ * implying that some of its packets will not be transferred; if the flag
+ * is set then the URB will be scheduled in the first unexpired slot,
+ * breaking the queue's synchronization.  Upon URB completion, the
+ * start_frame field will be set to the (micro)frame number in which the
+ * transfer was scheduled.  Ranges for frame counter values are HC-specific
+ * and can go from as low as 256 to as high as 65536 frames.
  *
  * Isochronous URBs have a different data transfer model, in part because
  * the quality of service is only "best effort".  Callers provide specially