Patch "cdc_ncm: toggle altsetting to force reset before setup" has been added to the 3.14-stable tree

Patch "cdc_ncm: toggle altsetting to force reset before setup" has been added to the 3.14-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    cdc_ncm: toggle altsetting to force reset before setup

to the 3.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     cdc_ncm-toggle-altsetting-to-force-reset-before-setup.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sat Apr 16 22:36:37 PDT 2016
From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>
Date: Thu, 3 Mar 2016 22:20:53 +0100
Subject: cdc_ncm: toggle altsetting to force reset before setup
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Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
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From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@mork.no>

[ Upstream commit 48906f62c96cc2cd35753e59310cb70eb08cc6a5 ]

Some devices will silently fail setup unless they are reset first.
This is necessary even if the data interface is already in
altsetting 0, which it will be when the device is probed for the
first time.  Briefly toggling the altsetting forces a function
reset regardless of the initial state.

This fixes a setup problem observed on a number of Huawei devices,
appearing to operate in NTB-32 mode even if we explicitly set them
to NTB-16 mode.

Signed-off-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/usb/cdc_ncm.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -423,7 +423,11 @@ advance:
 
 	iface_no = ctx->data->cur_altsetting->desc.bInterfaceNumber;
 
-	/* reset data interface */
+	/* Reset data interface. Some devices will not reset properly
+	 * unless they are configured first.  Toggle the altsetting to
+	 * force a reset
+	 */
+	usb_set_interface(dev->udev, iface_no, data_altsetting);
 	temp = usb_set_interface(dev->udev, iface_no, 0);
 	if (temp) {
 		dev_dbg(&intf->dev, "set interface failed\n");


Patches currently in stable-queue which might be from bjorn@mork.no are

queue-3.14/qmi_wwan-add-d-link-dwm-221-b1-device-id.patch
queue-3.14/cdc_ncm-toggle-altsetting-to-force-reset-before-setup.patch