1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/hid/usbhid/hid-core.c b/drivers/hid/usbhid/hid-core.c
index c1a1dd54601c..aa1c503a9526 100644
--- a/drivers/hid/usbhid/hid-core.c
+++ b/drivers/hid/usbhid/hid-core.c
@@ -28,6 +28,7 @@
 #include <linux/input.h>
 #include <linux/wait.h>
 #include <linux/workqueue.h>
+#include <linux/string.h>
 
 #include <linux/usb.h>
 
@@ -1364,7 +1365,34 @@ static int hid_post_reset(struct usb_interface *intf)
         struct usb_device *dev = interface_to_usbdev (intf);
         struct hid_device *hid = usb_get_intfdata(intf);
         struct usbhid_device *usbhid = hid->driver_data;
+        struct usb_host_interface *interface = intf->cur_altsetting;
         int status;
+        char *rdesc;
+
+        /* Fetch and examine the HID report descriptor. If this
+         * has changed, then rebind. Since usbcore's check of the
+         * configuration descriptors passed, we already know that
+         * the size of the HID report descriptor has not changed.
+         */
+        rdesc = kmalloc(hid->rsize, GFP_KERNEL);
+        if (!rdesc) {
+                dbg_hid("couldn't allocate rdesc memory (post_reset)\n");
+                return 1;
+        }
+        status = hid_get_class_descriptor(dev,
+                                interface->desc.bInterfaceNumber,
+                                HID_DT_REPORT, rdesc, hid->rsize);
+        if (status < 0) {
+                dbg_hid("reading report descriptor failed (post_reset)\n");
+                kfree(rdesc);
+                return 1;
+        }
+        status = memcmp(rdesc, hid->rdesc, hid->rsize);
+        kfree(rdesc);
+        if (status != 0) {
+                dbg_hid("report descriptor changed\n");
+                return 1;
+        }
 
         spin_lock_irq(&usbhid->lock);
         clear_bit(HID_RESET_PENDING, &usbhid->iofl);