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-rw-r--r--drivers/hid/usbhid/hid-core.c28
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);