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 4.4-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-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Sat Apr 16 10:02:53 PDT 2016 From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@xxxxxxx> Date: Thu, 3 Mar 2016 22:20:53 +0100 Subject: cdc_ncm: toggle altsetting to force reset before setup MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: =?UTF-8?q?Bj=C3=B8rn=20Mork?= <bjorn@xxxxxxx> [ 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@xxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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 @@ -794,7 +794,11 @@ int cdc_ncm_bind_common(struct usbnet *d 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@xxxxxxx are queue-4.4/qmi_wwan-add-sierra-wireless-em74xx-device-id.patch queue-4.4/qmi_wwan-add-d-link-dwm-221-b1-device-id.patch queue-4.4/cdc_ncm-toggle-altsetting-to-force-reset-before-setup.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html