NET: usb: cdc_mbim: add quirk for supporting Telit LE922A

Telit LE922A MBIM based composition does not work properly
with altsetting toggle done in cdc_ncm_bind_common.

This patch adds CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE quirk
to avoid this procedure that, instead, is mandatory for
other modems.

Signed-off-by: Daniele Palmas <dnlplm@gmail.com>
Reviewed-by: Bjørn Mork <bjorn@mork.no>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/cdc_mbim.c b/drivers/net/usb/cdc_mbim.c
index 96a5028..3a98f37 100644
--- a/drivers/net/usb/cdc_mbim.c
+++ b/drivers/net/usb/cdc_mbim.c
@@ -602,6 +602,21 @@ static const struct driver_info cdc_mbim_info_ndp_to_end = {
 	.data = CDC_NCM_FLAG_NDP_TO_END,
 };
 
+/* Some modems (e.g. Telit LE922A6) do not work properly with altsetting
+ * toggle done in cdc_ncm_bind_common. CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE
+ * flag is used to avoid this procedure.
+ */
+static const struct driver_info cdc_mbim_info_avoid_altsetting_toggle = {
+	.description = "CDC MBIM",
+	.flags = FLAG_NO_SETINT | FLAG_MULTI_PACKET | FLAG_WWAN,
+	.bind = cdc_mbim_bind,
+	.unbind = cdc_mbim_unbind,
+	.manage_power = cdc_mbim_manage_power,
+	.rx_fixup = cdc_mbim_rx_fixup,
+	.tx_fixup = cdc_mbim_tx_fixup,
+	.data = CDC_MBIM_FLAG_AVOID_ALTSETTING_TOGGLE,
+};
+
 static const struct usb_device_id mbim_devs[] = {
 	/* This duplicate NCM entry is intentional. MBIM devices can
 	 * be disguised as NCM by default, and this is necessary to
@@ -626,6 +641,12 @@ static const struct usb_device_id mbim_devs[] = {
 	{ USB_VENDOR_AND_INTERFACE_INFO(0x12d1, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 	  .driver_info = (unsigned long)&cdc_mbim_info_ndp_to_end,
 	},
+
+	/* Telit LE922A6 in MBIM composition */
+	{ USB_DEVICE_AND_INTERFACE_INFO(0x1bc7, 0x1041, USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
+	  .driver_info = (unsigned long)&cdc_mbim_info_avoid_altsetting_toggle,
+	},
+
 	/* default entry */
 	{ USB_INTERFACE_INFO(USB_CLASS_COMM, USB_CDC_SUBCLASS_MBIM, USB_CDC_PROTO_NONE),
 	  .driver_info = (unsigned long)&cdc_mbim_info_zlp,