USB: gadget rndis: send notifications

It turns out that atomic_inc_return() returns the *new* value
not the original one, so the logic in rndis_response_available()
kept the first RNDIS response notification from getting out.
This prevented interoperation with MS-Windows (but not Linux).

Fix this to make RNDIS behave again.

Signed-off-by: Richard Röjfors <richard.rojfors@endian.se>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/gadget/f_rndis.c b/drivers/usb/gadget/f_rndis.c
index 8afb14a..428b599 100644 (file)
--- a/drivers/usb/gadget/f_rndis.c
+++ b/drivers/usb/gadget/f_rndis.c
@@ -302,7 +302,7 @@ static void rndis_response_available(void *_rndis)
        __le32                          *data = req->buf;
        int                             status;
 
-       if (atomic_inc_return(&rndis->notify_count))
+       if (atomic_inc_return(&rndis->notify_count) != 1)
                return;
 
        /* Send RNDIS RESPONSE_AVAILABLE notification; a