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

cdc_ncm: Set NTB format again after altsetting switch for Huawei devices

to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: cdc_ncm-set-ntb-format-again-after-altsetting-switch-for-huawei-devices.patch and it can be found in the queue-4.9 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 2b02c20ce0c28974b44e69a2e2f5ddc6a470ad6f Mon Sep 17 00:00:00 2001

From: Enrico Mioso mrkiko.rs@gmail.com Date: Tue, 11 Jul 2017 17:21:52 +0200 Subject: cdc_ncm: Set NTB format again after altsetting switch for Huawei devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

From: Enrico Mioso mrkiko.rs@gmail.com

commit 2b02c20ce0c28974b44e69a2e2f5ddc6a470ad6f upstream.

Some firmwares in Huawei E3372H devices have been observed to switch back to NTB 32-bit format after altsetting switch. This patch implements a driver flag to check for the device settings and set NTB format to 16-bit again if needed. The flag has been activated for devices controlled by the huawei_cdc_ncm.c driver.

V1->V2: - fixed broken error checks - some corrections to the commit message V2->V3: - variable name changes, to clarify what's happening - check (and possibly set) the NTB format later in the common bind code path

Signed-off-by: Enrico Mioso mrkiko.rs@gmail.com Reported-and-tested-by: Christian Panton christian@panton.org Reviewed-by: Bjørn Mork bjorn@mork.no CC: Bjørn Mork bjorn@mork.no CC: Christian Panton christian@panton.org CC: linux-usb@vger.kernel.org CC: netdev@vger.kernel.org CC: Oliver Neukum oliver@neukum.org Signed-off-by: David S. Miller davem@davemloft.net Cc: Porto Rio porto.rio@gmx.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- drivers/net/usb/cdc_ncm.c | 28 ++++++++++++++++++++++++++++ drivers/net/usb/huawei_cdc_ncm.c | 6 ++++++ include/linux/usb/cdc_ncm.h | 1 + 3 files changed, 35 insertions(+)

--- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -769,8 +769,10 @@ int cdc_ncm_bind_common(struct usbnet *d u8 *buf; int len; int temp; + int err; u8 iface_no; struct usb_cdc_parsed_header hdr; + u16 curr_ntb_format;

ctx = kzalloc(sizeof(*ctx), GFP_KERNEL); if (!ctx) @@ -875,6 +877,32 @@ int cdc_ncm_bind_common(struct usbnet *d goto error2; }

+ /* + * Some Huawei devices have been observed to come out of reset in NDP32 mode. + * Let's check if this is the case, and set the device to NDP16 mode again if + * needed. + */ + if (ctx->drvflags & CDC_NCM_FLAG_RESET_NTB16) { + err = usbnet_read_cmd(dev, USB_CDC_GET_NTB_FORMAT, + USB_TYPE_CLASS | USB_DIR_IN | USB_RECIP_INTERFACE, + 0, iface_no, &curr_ntb_format, 2); + if (err < 0) { + goto error2; + } + + if (curr_ntb_format == USB_CDC_NCM_NTB32_FORMAT) { + dev_info(&intf->dev, "resetting NTB format to 16-bit"); + err = usbnet_write_cmd(dev, USB_CDC_SET_NTB_FORMAT, + USB_TYPE_CLASS | USB_DIR_OUT + | USB_RECIP_INTERFACE, + USB_CDC_NCM_NTB16_FORMAT, + iface_no, NULL, 0); + + if (err < 0) + goto error2; + } + } + cdc_ncm_find_endpoints(dev, ctx->data); cdc_ncm_find_endpoints(dev, ctx->control); if (!dev->in || !dev->out || !dev->status) { --- a/drivers/net/usb/huawei_cdc_ncm.c +++ b/drivers/net/usb/huawei_cdc_ncm.c @@ -80,6 +80,12 @@ static int huawei_cdc_ncm_bind(struct us * be at the end of the frame. */ drvflags |= CDC_NCM_FLAG_NDP_TO_END; + + /* Additionally, it has been reported that some Huawei E3372H devices, with + * firmware version 21.318.01.00.541, come out of reset in NTB32 format mode, hence + * needing to be set to the NTB16 one again. + */ + drvflags |= CDC_NCM_FLAG_RESET_NTB16; ret = cdc_ncm_bind_common(usbnet_dev, intf, 1, drvflags); if (ret) goto err; --- a/include/linux/usb/cdc_ncm.h +++ b/include/linux/usb/cdc_ncm.h @@ -83,6 +83,7 @@ /* Driver flags */ #define CDC_NCM_FLAG_NDP_TO_END 0x02 /* NDP is placed at end of frame */ #define CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE 0x04 /* Avoid altsetting toggle during init */ +#define CDC_NCM_FLAG_RESET_NTB16 0x08 /* set NDP16 one more time after altsetting switch */

#define cdc_ncm_comm_intf_is_mbim(x) ((x)->desc.bInterfaceSubClass == USB_CDC_SUBCLASS_MBIM && \ (x)->desc.bInterfaceProtocol == USB_CDC_PROTO_NONE)

Patches currently in stable-queue which might be from mrkiko.rs@gmail.com are

queue-4.9/cdc_ncm-set-ntb-format-again-after-altsetting-switch-for-huawei-devices.patch