[PATCH] USB: gadgetfs: set "zero" flag for short control-IN response

This patch (as622) makes gadgetfs set the "zero" flag for control-IN
responses, when the length of the response is shorter than the length of
the request.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index 9a4edc5657aa..0aab7d24c768 100644
--- a/drivers/usb/gadget/inode.c
+++ b/drivers/usb/gadget/inode.c
@@ -135,6 +135,7 @@ struct dev_data {
                                         setup_out_ready : 1,
                                         setup_out_error : 1,
                                         setup_abort : 1;
+        unsigned                        setup_wLength;
 
         /* the rest is basically write-once */
         struct usb_config_descriptor    *config, *hs_config;
@@ -942,6 +943,7 @@ static int setup_req (struct usb_ep *ep, struct usb_request *req, u16 len)
         }
         req->complete = ep0_complete;
         req->length = len;
+        req->zero = 0;
         return 0;
 }
 
@@ -1161,10 +1163,13 @@ ep0_write (struct file *fd, const char __user *buf, size_t len, loff_t *ptr)
                                 spin_unlock_irq (&dev->lock);
                                 if (copy_from_user (dev->req->buf, buf, len))
                                         retval = -EFAULT;
-                                else
+                                else {
+                                        if (len < dev->setup_wLength)
+                                                dev->req->zero = 1;
                                         retval = usb_ep_queue (
                                                 dev->gadget->ep0, dev->req,
                                                 GFP_KERNEL);
+                                }
                                 if (retval < 0) {
                                         spin_lock_irq (&dev->lock);
                                         clean_req (dev->gadget->ep0, dev->req);
@@ -1483,6 +1488,7 @@ unrecognized:
 delegate:
                         dev->setup_in = (ctrl->bRequestType & USB_DIR_IN)
                                                 ? 1 : 0;
+                        dev->setup_wLength = w_length;
                         dev->setup_out_ready = 0;
                         dev->setup_out_error = 0;
                         value = 0;