1 files changed, 20 insertions, 8 deletions

diff --git a/drivers/usb/core/generic.c b/drivers/usb/core/generic.c
index ebb20ff7ac58..b531a4fd30c2 100644
--- a/drivers/usb/core/generic.c
+++ b/drivers/usb/core/generic.c
@@ -25,6 +25,20 @@ static inline const char *plural(int n)
         return (n == 1 ? "" : "s");
 }
 
+static int is_rndis(struct usb_interface_descriptor *desc)
+{
+        return desc->bInterfaceClass == USB_CLASS_COMM
+                && desc->bInterfaceSubClass == 2
+                && desc->bInterfaceProtocol == 0xff;
+}
+
+static int is_activesync(struct usb_interface_descriptor *desc)
+{
+        return desc->bInterfaceClass == USB_CLASS_MISC
+                && desc->bInterfaceSubClass == 1
+                && desc->bInterfaceProtocol == 1;
+}
+
 static int choose_configuration(struct usb_device *udev)
 {
         int i;
@@ -87,14 +101,12 @@ static int choose_configuration(struct usb_device *udev)
                         continue;
                 }
 
-                /* If the first config's first interface is COMM/2/0xff
-                 * (MSFT RNDIS), rule it out unless Linux has host-side
-                 * RNDIS support. */
-                if (i == 0 && desc
-                                && desc->bInterfaceClass == USB_CLASS_COMM
-                                && desc->bInterfaceSubClass == 2
-                                && desc->bInterfaceProtocol == 0xff) {
-#ifndef CONFIG_USB_NET_RNDIS_HOST
+                /* When the first config's first interface is one of Microsoft's
+                 * pet nonstandard Ethernet-over-USB protocols, ignore it unless
+                 * this kernel has enabled the necessary host side driver.
+                 */
+                if (i == 0 && desc && (is_rndis(desc) || is_activesync(desc))) {
+#if !defined(CONFIG_USB_NET_RNDIS_HOST) && !defined(CONFIG_USB_NET_RNDIS_HOST_MODULE)
                         continue;
 #else
                         best = c;