[ 10/23] usb: Clear both buffers when clearing a control transfer TT buffer.

Greg Kroah-Hartman
2013-08-02T10:26:48Z

From: William Gulland <wgulland@google.com>

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 | 9 +++++++++
1 file changed, 9 insertions(+)

--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -463,6 +463,15 @@ 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);