usb: Clear both buffers when clearing a control transfer TT buffer.
authorWilliam Gulland <wgulland@google.com>
Thu, 27 Jun 2013 23:10:20 +0000 (16:10 -0700)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 25 Jul 2013 18:37:13 +0000 (11:37 -0700)
Control transfers have both IN and OUT (or SETUP) packets, so when
clearing TT buffers for a control transfer it's necessary to send
two HUB_CLEAR_TT_BUFFER requests to the hub.

Signed-off-by: William Gulland <wgulland@google.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/core/hub.c

index c857471519e3a641b6917bd7425b790d34039978..4a8a1d68002c0fa1695078c6566c616bf764fa35 100644 (file)
@@ -668,6 +668,15 @@ resubmit:
 static inline int
 hub_clear_tt_buffer (struct usb_device *hdev, u16 devinfo, u16 tt)
 {
+       /* Need to clear both directions for control ep */
+       if (((devinfo >> 11) & USB_ENDPOINT_XFERTYPE_MASK) ==
+                       USB_ENDPOINT_XFER_CONTROL) {
+               int status = usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
+                               HUB_CLEAR_TT_BUFFER, USB_RT_PORT,
+                               devinfo ^ 0x8000, tt, NULL, 0, 1000);
+               if (status)
+                       return status;
+       }
        return usb_control_msg(hdev, usb_sndctrlpipe(hdev, 0),
                               HUB_CLEAR_TT_BUFFER, USB_RT_PORT, devinfo,
                               tt, NULL, 0, 1000);