[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>

diff --git a/drivers/usb/gadget/inode.c b/drivers/usb/gadget/inode.c
index 9a4edc5..0aab7d2 100644 (file)
--- 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;