usb: Clear both buffers when clearing a control transfer TT buffer.
William Gulland [Thu, 27 Jun 2013 23:10:20 +0000 (16:10 -0700)]
commit 2c7b871b9102c497ba8f972aa5d38532f05b654d upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/core/hub.c

index 49b139c..a969ec1 100644 (file)
@@ -488,6 +488,15 @@ 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);