4 files changed, 50 insertions, 61 deletions

diff --git a/drivers/net/usb/Kconfig b/drivers/net/usb/Kconfig
index 3b6e9b83342d..7c769d8e25ad 100644
--- a/drivers/net/usb/Kconfig
+++ b/drivers/net/usb/Kconfig
@@ -268,7 +268,7 @@ config USB_NET_SMSC75XX
         select CRC16
         select CRC32
         help
-          This option adds support for SMSC LAN95XX based USB 2.0
+          This option adds support for SMSC LAN75XX based USB 2.0
           Gigabit Ethernet adapters.
 
 config USB_NET_SMSC95XX
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index 248d2dc765a5..16c842997291 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -68,18 +68,9 @@ static int cdc_mbim_bind(struct usbnet *dev, struct usb_interface *intf)
         struct cdc_ncm_ctx *ctx;
         struct usb_driver *subdriver = ERR_PTR(-ENODEV);
         int ret = -ENODEV;
-        u8 data_altsetting = CDC_NCM_DATA_ALTSETTING_NCM;
+        u8 data_altsetting = cdc_ncm_select_altsetting(dev, intf);
         struct cdc_mbim_state *info = (void *)&dev->data;
 
-        /* see if interface supports MBIM alternate setting */
-        if (intf->num_altsetting == 2) {
-                if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
-                        usb_set_interface(dev->udev,
-                                          intf->cur_altsetting->desc.bInterfaceNumber,
-                                          CDC_NCM_COMM_ALTSETTING_MBIM);
-                data_altsetting = CDC_NCM_DATA_ALTSETTING_MBIM;
-        }
-
         /* Probably NCM, defer for cdc_ncm_bind */
         if (!cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
                 goto err;
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c
index 61b74a2b89ac..4709fa3497cf 100644
--- a/drivers/net/usb/cdc_ncm.c
+++ b/drivers/net/usb/cdc_ncm.c
@@ -55,6 +55,14 @@
 
 #define DRIVER_VERSION                          "14-Mar-2012"
 
+#if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM)
+static bool prefer_mbim = true;
+#else
+static bool prefer_mbim;
+#endif
+module_param(prefer_mbim, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(prefer_mbim, "Prefer MBIM setting on dual NCM/MBIM functions");
+
 static void cdc_ncm_txpath_bh(unsigned long param);
 static void cdc_ncm_tx_timeout_start(struct cdc_ncm_ctx *ctx);
 static enum hrtimer_restart cdc_ncm_tx_timer_cb(struct hrtimer *hr_timer);
@@ -550,9 +558,12 @@ void cdc_ncm_unbind(struct usbnet *dev, struct usb_interface *intf)
 }
 EXPORT_SYMBOL_GPL(cdc_ncm_unbind);
 
-static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
+/* Select the MBIM altsetting iff it is preferred and available,
+ * returning the number of the corresponding data interface altsetting
+ */
+u8 cdc_ncm_select_altsetting(struct usbnet *dev, struct usb_interface *intf)
 {
-        int ret;
+        struct usb_host_interface *alt;
 
         /* The MBIM spec defines a NCM compatible default altsetting,
          * which we may have matched:
@@ -568,23 +579,27 @@ static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
          *   endpoint descriptors, shall be constructed according to
          *   the rules given in section 6 (USB Device Model) of this
          *   specification."
-         *
-         * Do not bind to such interfaces, allowing cdc_mbim to handle
-         * them
          */
-#if IS_ENABLED(CONFIG_USB_NET_CDC_MBIM)
-        if ((intf->num_altsetting == 2) &&
-            !usb_set_interface(dev->udev,
-                               intf->cur_altsetting->desc.bInterfaceNumber,
-                               CDC_NCM_COMM_ALTSETTING_MBIM)) {
-                if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
-                        return -ENODEV;
-                else
-                        usb_set_interface(dev->udev,
-                                          intf->cur_altsetting->desc.bInterfaceNumber,
-                                          CDC_NCM_COMM_ALTSETTING_NCM);
+        if (prefer_mbim && intf->num_altsetting == 2) {
+                alt = usb_altnum_to_altsetting(intf, CDC_NCM_COMM_ALTSETTING_MBIM);
+                if (alt && cdc_ncm_comm_intf_is_mbim(alt) &&
+                    !usb_set_interface(dev->udev,
+                                       intf->cur_altsetting->desc.bInterfaceNumber,
+                                       CDC_NCM_COMM_ALTSETTING_MBIM))
+                        return CDC_NCM_DATA_ALTSETTING_MBIM;
         }
-#endif
+        return CDC_NCM_DATA_ALTSETTING_NCM;
+}
+EXPORT_SYMBOL_GPL(cdc_ncm_select_altsetting);
+
+static int cdc_ncm_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+        int ret;
+
+        /* MBIM backwards compatible function? */
+        cdc_ncm_select_altsetting(dev, intf);
+        if (cdc_ncm_comm_intf_is_mbim(intf->cur_altsetting))
+                return -ENODEV;
 
         /* NCM data altsetting is always 1 */
         ret = cdc_ncm_bind_common(dev, intf, 1);
diff --git a/drivers/net/usb/qmi_wwan.c b/drivers/net/usb/qmi_wwan.c
index efb5c7c33a28..968d5d50751d 100644
--- a/drivers/net/usb/qmi_wwan.c
+++ b/drivers/net/usb/qmi_wwan.c
@@ -139,16 +139,9 @@ static int qmi_wwan_bind(struct usbnet *dev, struct usb_interface *intf)
 
         BUILD_BUG_ON((sizeof(((struct usbnet *)0)->data) < sizeof(struct qmi_wwan_state)));
 
-        /* control and data is shared? */
-        if (intf->cur_altsetting->desc.bNumEndpoints == 3) {
-                info->control = intf;
-                info->data = intf;
-                goto shared;
-        }
-
-        /* else require a single interrupt status endpoint on control intf */
-        if (intf->cur_altsetting->desc.bNumEndpoints != 1)
-                goto err;
+        /* set up initial state */
+        info->control = intf;
+        info->data = intf;
 
         /* and a number of CDC descriptors */
         while (len > 3) {
@@ -207,25 +200,14 @@ next_desc:
                 buf += h->bLength;
         }
 
-        /* did we find all the required ones? */
-        if (!(found & (1 << USB_CDC_HEADER_TYPE)) ||
-            !(found & (1 << USB_CDC_UNION_TYPE))) {
-                dev_err(&intf->dev, "CDC functional descriptors missing\n");
-                goto err;
-        }
-
-        /* verify CDC Union */
-        if (desc->bInterfaceNumber != cdc_union->bMasterInterface0) {
-                dev_err(&intf->dev, "bogus CDC Union: master=%u\n", cdc_union->bMasterInterface0);
-                goto err;
-        }
-
-        /* need to save these for unbind */
-        info->control = intf;
-        info->data = usb_ifnum_to_if(dev->udev, cdc_union->bSlaveInterface0);
-        if (!info->data) {
-                dev_err(&intf->dev, "bogus CDC Union: slave=%u\n", cdc_union->bSlaveInterface0);
-                goto err;
+        /* Use separate control and data interfaces if we found a CDC Union */
+        if (cdc_union) {
+                info->data = usb_ifnum_to_if(dev->udev, cdc_union->bSlaveInterface0);
+                if (desc->bInterfaceNumber != cdc_union->bMasterInterface0 || !info->data) {
+                        dev_err(&intf->dev, "bogus CDC Union: master=%u, slave=%u\n",
+                                cdc_union->bMasterInterface0, cdc_union->bSlaveInterface0);
+                        goto err;
+                }
         }
 
         /* errors aren't fatal - we can live with the dynamic address */
@@ -235,11 +217,12 @@ next_desc:
         }
 
         /* claim data interface and set it up */
-        status = usb_driver_claim_interface(driver, info->data, dev);
-        if (status < 0)
-                goto err;
+        if (info->control != info->data) {
+                status = usb_driver_claim_interface(driver, info->data, dev);
+                if (status < 0)
+                        goto err;
+        }
 
-shared:
         status = qmi_wwan_register_subdriver(dev);
         if (status < 0 && info->control != info->data) {
                 usb_set_intfdata(info->data, NULL);