1 files changed, 28 insertions, 0 deletions

diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index d103a1d4fb36..8f572b9f3625 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -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,
+                                      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) {