Commit 2b02c20c authored by Enrico Mioso's avatar Enrico Mioso Committed by David S. Miller
Browse files

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

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

- fixed broken error checks
- some corrections to the commit message
- 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: default avatarEnrico Mioso <>
Reported-and-tested-by: default avatarChristian Panton <>
Reviewed-by: default avatarBjørn Mork <>
CC: Bjørn Mork <>
CC: Christian Panton <>
CC: Oliver Neukum <>
Signed-off-by: default avatarDavid S. Miller <>
parent 457839ed
......@@ -768,8 +768,10 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
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)
......@@ -874,6 +876,32 @@ int cdc_ncm_bind_common(struct usbnet *dev, struct usb_interface *intf, u8 data_
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,
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,
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) {
......@@ -80,6 +80,12 @@ static int huawei_cdc_ncm_bind(struct usbnet *usbnet_dev,
* 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;
......@@ -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)
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