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);