1 files changed, 79 insertions, 4 deletions

diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 217a3d6d0a06..b7434787db5f 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -412,10 +412,24 @@ int usb_sg_init (
                 io->urbs [i]->status = -EINPROGRESS;
                 io->urbs [i]->actual_length = 0;
 
+                /*
+                 * Some systems need to revert to PIO when DMA is temporarily
+                 * unavailable.  For their sakes, both transfer_buffer and
+                 * transfer_dma are set when possible.  However this can only
+                 * work on systems without HIGHMEM, since DMA buffers located
+                 * in high memory are not directly addressable by the CPU for
+                 * PIO ... so when HIGHMEM is in use, transfer_buffer is NULL
+                 * to prevent stale pointers and to help spot bugs.
+                 */
                 if (dma) {
-                        /* hc may use _only_ transfer_dma */
                         io->urbs [i]->transfer_dma = sg_dma_address (sg + i);
                         len = sg_dma_len (sg + i);
+#ifdef CONFIG_HIGHMEM
+                        io->urbs[i]->transfer_buffer = NULL;
+#else
+                        io->urbs[i]->transfer_buffer =
+                                page_address(sg[i].page) + sg[i].offset;
+#endif
                 } else {
                         /* hc may use _only_ transfer_buffer */
                         io->urbs [i]->transfer_buffer =
@@ -1305,7 +1319,7 @@ int usb_reset_configuration(struct usb_device *dev)
         return 0;
 }
 
-static void release_interface(struct device *dev)
+void usb_release_interface(struct device *dev)
 {
         struct usb_interface *intf = to_usb_interface(dev);
         struct usb_interface_cache *intfc =
@@ -1315,6 +1329,67 @@ static void release_interface(struct device *dev)
         kfree(intf);
 }
 
+#ifdef  CONFIG_HOTPLUG
+static int usb_if_uevent(struct device *dev, char **envp, int num_envp,
+                 char *buffer, int buffer_size)
+{
+        struct usb_device *usb_dev;
+        struct usb_interface *intf;
+        struct usb_host_interface *alt;
+        int i = 0;
+        int length = 0;
+
+        if (!dev)
+                return -ENODEV;
+
+        /* driver is often null here; dev_dbg() would oops */
+        pr_debug ("usb %s: uevent\n", dev->bus_id);
+
+        intf = to_usb_interface(dev);
+        usb_dev = interface_to_usbdev(intf);
+        alt = intf->cur_altsetting;
+
+        if (add_uevent_var(envp, num_envp, &i,
+                   buffer, buffer_size, &length,
+                   "INTERFACE=%d/%d/%d",
+                   alt->desc.bInterfaceClass,
+                   alt->desc.bInterfaceSubClass,
+                   alt->desc.bInterfaceProtocol))
+                return -ENOMEM;
+
+        if (add_uevent_var(envp, num_envp, &i,
+                   buffer, buffer_size, &length,
+                   "MODALIAS=usb:v%04Xp%04Xd%04Xdc%02Xdsc%02Xdp%02Xic%02Xisc%02Xip%02X",
+                   le16_to_cpu(usb_dev->descriptor.idVendor),
+                   le16_to_cpu(usb_dev->descriptor.idProduct),
+                   le16_to_cpu(usb_dev->descriptor.bcdDevice),
+                   usb_dev->descriptor.bDeviceClass,
+                   usb_dev->descriptor.bDeviceSubClass,
+                   usb_dev->descriptor.bDeviceProtocol,
+                   alt->desc.bInterfaceClass,
+                   alt->desc.bInterfaceSubClass,
+                   alt->desc.bInterfaceProtocol))
+                return -ENOMEM;
+
+        envp[i] = NULL;
+        return 0;
+}
+
+#else
+
+static int usb_if_uevent(struct device *dev, char **envp,
+                         int num_envp, char *buffer, int buffer_size)
+{
+        return -ENODEV;
+}
+#endif  /* CONFIG_HOTPLUG */
+
+struct device_type usb_if_device_type = {
+        .name =         "usb_interface",
+        .release =      usb_release_interface,
+        .uevent =       usb_if_uevent,
+};
+
 /*
  * usb_set_configuration - Makes a particular device setting be current
  * @dev: the device whose configuration is being updated
@@ -1349,7 +1424,7 @@ static void release_interface(struct device *dev)
  *
  * This call is synchronous. The calling context must be able to sleep,
  * must own the device lock, and must not hold the driver model's USB
- * bus rwsem; usb device driver probe() methods cannot use this routine.
+ * bus mutex; usb device driver probe() methods cannot use this routine.
  *
  * Returns zero on success, or else the status code returned by the
  * underlying call that failed.  On successful completion, each interface
@@ -1478,8 +1553,8 @@ free_interfaces:
                 intf->dev.parent = &dev->dev;
                 intf->dev.driver = NULL;
                 intf->dev.bus = &usb_bus_type;
+                intf->dev.type = &usb_if_device_type;
                 intf->dev.dma_mask = dev->dev.dma_mask;
-                intf->dev.release = release_interface;
                 device_initialize (&intf->dev);
                 mark_quiesced(intf);
                 sprintf (&intf->dev.bus_id[0], "%d-%s:%d.%d",