Index: linux-4.14.95/drivers/net/usb/qmi_wwan.c
===================================================================
--- linux-4.14.95.orig/drivers/net/usb/qmi_wwan.c
+++ linux-4.14.95/drivers/net/usb/qmi_wwan.c
@@ -63,6 +63,7 @@ enum qmi_wwan_flags {
 
 enum qmi_wwan_quirks {
 	QMI_WWAN_QUIRK_DTR = 1 << 0,	/* needs "set DTR" request */
+	QMI_WWAN_QUIRK_QUECTEL_DYNCFG = 1 << 1,	/* check num. endpoints */
 };
 
 struct qmimux_hdr {
@@ -844,6 +845,16 @@ static const struct driver_info	qmi_wwan
 	.data           = QMI_WWAN_QUIRK_DTR,
 };
 
+static const struct driver_info	qmi_wwan_info_quirk_quectel_dyncfg = {
+	.description	= "WWAN/QMI device",
+	.flags		= FLAG_WWAN | FLAG_SEND_ZLP,
+	.bind		= qmi_wwan_bind,
+	.unbind		= qmi_wwan_unbind,
+	.manage_power	= qmi_wwan_manage_power,
+	.rx_fixup       = qmi_wwan_rx_fixup,
+	.data           = QMI_WWAN_QUIRK_DTR | QMI_WWAN_QUIRK_QUECTEL_DYNCFG,
+};
+
 #define HUAWEI_VENDOR_ID	0x12D1
 
 /* map QMI/wwan function by a fixed interface number */
@@ -864,6 +875,15 @@ static const struct driver_info	qmi_wwan
 #define QMI_GOBI_DEVICE(vend, prod) \
 	QMI_FIXED_INTF(vend, prod, 0)
 
+/* Quectel does not use fixed interface numbers on at least some of their
+ * devices. We need to check the number of endpoints to ensure that we bind to
+ * the correct interface.
+ */
+#define QMI_QUIRK_QUECTEL_DYNCFG(vend, prod) \
+	USB_DEVICE_AND_INTERFACE_INFO(vend, prod, USB_CLASS_VENDOR_SPEC, \
+				      USB_SUBCLASS_VENDOR_SPEC, 0xff), \
+	.driver_info = (unsigned long)&qmi_wwan_info_quirk_quectel_dyncfg
+
 static const struct usb_device_id products[] = {
 	/* 1. CDC ECM like devices match on the control interface */
 	{	/* Huawei E392, E398 and possibly others sharing both device id and more... */
@@ -1317,7 +1337,8 @@ static const struct usb_device_id produc
 	{QMI_GOBI_DEVICE(0x1199, 0x901b)},	/* Sierra Wireless MC7770 */
 	{QMI_GOBI_DEVICE(0x12d1, 0x14f1)},	/* Sony Gobi 3000 Composite */
 	{QMI_GOBI_DEVICE(0x1410, 0xa021)},	/* Foxconn Gobi 3000 Modem device (Novatel E396) */
-
+	{QMI_QUIRK_QUECTEL_DYNCFG(0x2c7c, 0x0800)},	/* Quectel RM500Q-GL */
+	{QMI_QUIRK_QUECTEL_DYNCFG(0x2c7c, 0x0620)},	/* Quectel EM20 */
 	{ }					/* END */
 };
 MODULE_DEVICE_TABLE(usb, products);
Index: linux-4.14.95/drivers/usb/serial/option.c
===================================================================
--- linux-4.14.95.orig/drivers/usb/serial/option.c
+++ linux-4.14.95/drivers/usb/serial/option.c
@@ -249,6 +249,8 @@ static void option_instat_callback(struc
 #define QUECTEL_PRODUCT_EC25			0x0125
 #define QUECTEL_PRODUCT_BG96			0x0296
 #define QUECTEL_PRODUCT_EP06			0x0306
+#define QUECTEL_PRODUCT_RM500Q			0x0800
+#define QUECTEL_PRODUCT_EM20			0x0620
 
 #define CMOTECH_VENDOR_ID			0x16d8
 #define CMOTECH_PRODUCT_6001			0x6001
@@ -567,6 +569,9 @@ static void option_instat_callback(struc
 /* Interface must have two endpoints */
 #define NUMEP2		BIT(16)
 
+/* Device needs ZLP */
+#define ZLP		BIT(17)
+
 
 static const struct usb_device_id option_ids[] = {
 	{ USB_DEVICE(OPTION_VENDOR_ID, OPTION_PRODUCT_COLT) },
@@ -1962,6 +1967,14 @@ static const struct usb_device_id option
 	  .driver_info = RSVD(4) | RSVD(5) },
 	{ USB_DEVICE_INTERFACE_CLASS(0x2cb7, 0x0105, 0xff),			/* Fibocom NL678 series */
 	  .driver_info = RSVD(6) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(QUECTEL_VENDOR_ID, QUECTEL_PRODUCT_RM500Q, 0xff, 0xff, 0x10),
+	  .driver_info = ZLP },
+	{ USB_DEVICE_AND_INTERFACE_INFO(QUECTEL_VENDOR_ID, QUECTEL_PRODUCT_RM500Q, 0xff, 0xff, 0x30) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(QUECTEL_VENDOR_ID, QUECTEL_PRODUCT_RM500Q, 0xff, 0, 0) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(QUECTEL_VENDOR_ID, QUECTEL_PRODUCT_EM20, 0xff, 0xff, 0x10),
+	  .driver_info = ZLP },
+	{ USB_DEVICE_AND_INTERFACE_INFO(QUECTEL_VENDOR_ID, QUECTEL_PRODUCT_EM20, 0xff, 0xff, 0x30) },
+	{ USB_DEVICE_AND_INTERFACE_INFO(QUECTEL_VENDOR_ID, QUECTEL_PRODUCT_EM20, 0xff, 0, 0) },
 	{ } /* Terminating entry */
 };
 MODULE_DEVICE_TABLE(usb, option_ids);