Patchwork [104/106] usb: Clear both buffers when clearing a control transfer TT buffer.

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Submitter Luis Henriques
Date July 30, 2013, 9:32 a.m.
Message ID <1375176725-5825-105-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/263297/
State New
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Comments

Luis Henriques - July 30, 2013, 9:32 a.m.
3.5.7.18 -stable review patch.  If anyone has any objections, please let me know.

------------------

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>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/usb/core/hub.c | 9 +++++++++
 1 file changed, 9 insertions(+)

Patch

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 9d70788..d5515c0 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -710,6 +710,15 @@  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);