USB: report submission of active URBs

This patch (as1633) changes slightly the way usbcore handled
submissions of URBs that are already active.  It will now return
-EBUSY rather than -EINVAL, and it will call WARN_ONCE to draw
people's attention to the bug.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/Documentation/usb/error-codes.txt b/Documentation/usb/error-codes.txt
index 8d1e2a9..9c3eb84 100644 (file)
--- a/Documentation/usb/error-codes.txt
+++ b/Documentation/usb/error-codes.txt
@@ -21,6 +21,8 @@ Non-USB-specific:
 
 USB-specific:
 
+-EBUSY         The URB is already active.
+
 -ENODEV                specified USB-device or bus doesn't exist
 
 -ENOENT                specified interface or endpoint does not exist or

diff --git a/drivers/usb/core/urb.c b/drivers/usb/core/urb.c
index 3662287..e0d9d94 100644 (file)
--- a/drivers/usb/core/urb.c
+++ b/drivers/usb/core/urb.c
@@ -321,8 +321,13 @@ int usb_submit_urb(struct urb *urb, gfp_t mem_flags)
        struct usb_host_endpoint        *ep;
        int                             is_out;
 
-       if (!urb || urb->hcpriv || !urb->complete)
+       if (!urb || !urb->complete)
                return -EINVAL;
+       if (urb->hcpriv) {
+               WARN_ONCE(1, "URB %p submitted while active\n", urb);
+               return -EBUSY;
+       }
+
        dev = urb->dev;
        if ((!dev) || (dev->state < USB_STATE_UNAUTHENTICATED))
                return -ENODEV;