Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 490 insertions, 0 deletions

diff --git a/drivers/usb/serial/qcserial.c b/drivers/usb/serial/qcserial.c
new file mode 100644
index 000000000..105c0a0ea
--- /dev/null
+++ b/drivers/usb/serial/qcserial.c
@@ -0,0 +1,490 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Qualcomm Serial USB driver
+ *
+ *	Copyright (c) 2008 QUALCOMM Incorporated.
+ *	Copyright (c) 2009 Greg Kroah-Hartman <gregkh@suse.de>
+ *	Copyright (c) 2009 Novell Inc.
+ */
+
+#include <linux/tty.h>
+#include <linux/module.h>
+#include <linux/usb.h>
+#include <linux/usb/serial.h>
+#include <linux/slab.h>
+#include "usb-wwan.h"
+
+#define DRIVER_AUTHOR "Qualcomm Inc"
+#define DRIVER_DESC "Qualcomm USB Serial driver"
+
+#define QUECTEL_EC20_PID	0x9215
+
+/* standard device layouts supported by this driver */
+enum qcserial_layouts {
+	QCSERIAL_G2K = 0,	/* Gobi 2000 */
+	QCSERIAL_G1K = 1,	/* Gobi 1000 */
+	QCSERIAL_SWI = 2,	/* Sierra Wireless */
+	QCSERIAL_HWI = 3,	/* Huawei */
+};
+
+#define DEVICE_G1K(v, p) \
+	USB_DEVICE(v, p), .driver_info = QCSERIAL_G1K
+#define DEVICE_SWI(v, p) \
+	USB_DEVICE(v, p), .driver_info = QCSERIAL_SWI
+#define DEVICE_HWI(v, p) \
+	USB_DEVICE(v, p), .driver_info = QCSERIAL_HWI
+
+static const struct usb_device_id id_table[] = {
+	/* Gobi 1000 devices */
+	{DEVICE_G1K(0x05c6, 0x9211)},	/* Acer Gobi QDL device */
+	{DEVICE_G1K(0x05c6, 0x9212)},	/* Acer Gobi Modem Device */
+	{DEVICE_G1K(0x03f0, 0x1f1d)},	/* HP un2400 Gobi Modem Device */
+	{DEVICE_G1K(0x03f0, 0x201d)},	/* HP un2400 Gobi QDL Device */
+	{DEVICE_G1K(0x04da, 0x250d)},	/* Panasonic Gobi Modem device */
+	{DEVICE_G1K(0x04da, 0x250c)},	/* Panasonic Gobi QDL device */
+	{DEVICE_G1K(0x413c, 0x8172)},	/* Dell Gobi Modem device */
+	{DEVICE_G1K(0x413c, 0x8171)},	/* Dell Gobi QDL device */
+	{DEVICE_G1K(0x1410, 0xa001)},	/* Novatel/Verizon USB-1000 */
+	{DEVICE_G1K(0x1410, 0xa002)},	/* Novatel Gobi Modem device */
+	{DEVICE_G1K(0x1410, 0xa003)},	/* Novatel Gobi Modem device */
+	{DEVICE_G1K(0x1410, 0xa004)},	/* Novatel Gobi Modem device */
+	{DEVICE_G1K(0x1410, 0xa005)},	/* Novatel Gobi Modem device */
+	{DEVICE_G1K(0x1410, 0xa006)},	/* Novatel Gobi Modem device */
+	{DEVICE_G1K(0x1410, 0xa007)},	/* Novatel Gobi Modem device */
+	{DEVICE_G1K(0x1410, 0xa008)},	/* Novatel Gobi QDL device */
+	{DEVICE_G1K(0x0b05, 0x1776)},	/* Asus Gobi Modem device */
+	{DEVICE_G1K(0x0b05, 0x1774)},	/* Asus Gobi QDL device */
+	{DEVICE_G1K(0x19d2, 0xfff3)},	/* ONDA Gobi Modem device */
+	{DEVICE_G1K(0x19d2, 0xfff2)},	/* ONDA Gobi QDL device */
+	{DEVICE_G1K(0x1557, 0x0a80)},	/* OQO Gobi QDL device */
+	{DEVICE_G1K(0x05c6, 0x9001)},   /* Generic Gobi Modem device */
+	{DEVICE_G1K(0x05c6, 0x9002)},	/* Generic Gobi Modem device */
+	{DEVICE_G1K(0x05c6, 0x9202)},	/* Generic Gobi Modem device */
+	{DEVICE_G1K(0x05c6, 0x9203)},	/* Generic Gobi Modem device */
+	{DEVICE_G1K(0x05c6, 0x9222)},	/* Generic Gobi Modem device */
+	{DEVICE_G1K(0x05c6, 0x9008)},	/* Generic Gobi QDL device */
+	{DEVICE_G1K(0x05c6, 0x9009)},	/* Generic Gobi Modem device */
+	{DEVICE_G1K(0x05c6, 0x9201)},	/* Generic Gobi QDL device */
+	{DEVICE_G1K(0x05c6, 0x9221)},	/* Generic Gobi QDL device */
+	{DEVICE_G1K(0x05c6, 0x9231)},	/* Generic Gobi QDL device */
+	{DEVICE_G1K(0x1f45, 0x0001)},	/* Unknown Gobi QDL device */
+	{DEVICE_G1K(0x1bc7, 0x900e)},	/* Telit Gobi QDL device */
+
+	/* Gobi 2000 devices */
+	{USB_DEVICE(0x1410, 0xa010)},	/* Novatel Gobi 2000 QDL device */
+	{USB_DEVICE(0x1410, 0xa011)},	/* Novatel Gobi 2000 QDL device */
+	{USB_DEVICE(0x1410, 0xa012)},	/* Novatel Gobi 2000 QDL device */
+	{USB_DEVICE(0x1410, 0xa013)},	/* Novatel Gobi 2000 QDL device */
+	{USB_DEVICE(0x1410, 0xa014)},	/* Novatel Gobi 2000 QDL device */
+	{USB_DEVICE(0x413c, 0x8185)},	/* Dell Gobi 2000 QDL device (N0218, VU936) */
+	{USB_DEVICE(0x413c, 0x8186)},	/* Dell Gobi 2000 Modem device (N0218, VU936) */
+	{USB_DEVICE(0x05c6, 0x9208)},	/* Generic Gobi 2000 QDL device */
+	{USB_DEVICE(0x05c6, 0x920b)},	/* Generic Gobi 2000 Modem device */
+	{USB_DEVICE(0x05c6, 0x9224)},	/* Sony Gobi 2000 QDL device (N0279, VU730) */
+	{USB_DEVICE(0x05c6, 0x9225)},	/* Sony Gobi 2000 Modem device (N0279, VU730) */
+	{USB_DEVICE(0x05c6, 0x9244)},	/* Samsung Gobi 2000 QDL device (VL176) */
+	{USB_DEVICE(0x05c6, 0x9245)},	/* Samsung Gobi 2000 Modem device (VL176) */
+	{USB_DEVICE(0x03f0, 0x241d)},	/* HP Gobi 2000 QDL device (VP412) */
+	{USB_DEVICE(0x03f0, 0x251d)},	/* HP Gobi 2000 Modem device (VP412) */
+	{USB_DEVICE(0x05c6, 0x9214)},	/* Acer Gobi 2000 QDL device (VP413) */
+	{USB_DEVICE(0x05c6, 0x9215)},	/* Acer Gobi 2000 Modem device (VP413) */
+	{USB_DEVICE(0x05c6, 0x9264)},	/* Asus Gobi 2000 QDL device (VR305) */
+	{USB_DEVICE(0x05c6, 0x9265)},	/* Asus Gobi 2000 Modem device (VR305) */
+	{USB_DEVICE(0x05c6, 0x9234)},	/* Top Global Gobi 2000 QDL device (VR306) */
+	{USB_DEVICE(0x05c6, 0x9235)},	/* Top Global Gobi 2000 Modem device (VR306) */
+	{USB_DEVICE(0x05c6, 0x9274)},	/* iRex Technologies Gobi 2000 QDL device (VR307) */
+	{USB_DEVICE(0x05c6, 0x9275)},	/* iRex Technologies Gobi 2000 Modem device (VR307) */
+	{USB_DEVICE(0x1199, 0x9000)},	/* Sierra Wireless Gobi 2000 QDL device (VT773) */
+	{USB_DEVICE(0x1199, 0x9001)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9002)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9003)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9004)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9005)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9006)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9007)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9008)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9009)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x900a)},	/* Sierra Wireless Gobi 2000 Modem device (VT773) */
+	{USB_DEVICE(0x1199, 0x9011)},   /* Sierra Wireless Gobi 2000 Modem device (MC8305) */
+	{USB_DEVICE(0x16d8, 0x8001)},	/* CMDTech Gobi 2000 QDL device (VU922) */
+	{USB_DEVICE(0x16d8, 0x8002)},	/* CMDTech Gobi 2000 Modem device (VU922) */
+	{USB_DEVICE(0x05c6, 0x9204)},	/* Gobi 2000 QDL device */
+	{USB_DEVICE(0x05c6, 0x9205)},	/* Gobi 2000 Modem device */
+
+	/* Gobi 3000 devices */
+	{USB_DEVICE(0x03f0, 0x371d)},	/* HP un2430 Gobi 3000 QDL */
+	{USB_DEVICE(0x05c6, 0x920c)},	/* Gobi 3000 QDL */
+	{USB_DEVICE(0x05c6, 0x920d)},	/* Gobi 3000 Composite */
+	{USB_DEVICE(0x1410, 0xa020)},   /* Novatel Gobi 3000 QDL */
+	{USB_DEVICE(0x1410, 0xa021)},	/* Novatel Gobi 3000 Composite */
+	{USB_DEVICE(0x413c, 0x8193)},	/* Dell Gobi 3000 QDL */
+	{USB_DEVICE(0x413c, 0x8194)},	/* Dell Gobi 3000 Composite */
+	{USB_DEVICE(0x413c, 0x81a6)},	/* Dell DW5570 QDL (MC8805) */
+	{USB_DEVICE(0x1199, 0x68a4)},	/* Sierra Wireless QDL */
+	{USB_DEVICE(0x1199, 0x68a5)},	/* Sierra Wireless Modem */
+	{USB_DEVICE(0x1199, 0x68a8)},	/* Sierra Wireless QDL */
+	{USB_DEVICE(0x1199, 0x68a9)},	/* Sierra Wireless Modem */
+	{USB_DEVICE(0x1199, 0x9010)},	/* Sierra Wireless Gobi 3000 QDL */
+	{USB_DEVICE(0x1199, 0x9012)},	/* Sierra Wireless Gobi 3000 QDL */
+	{USB_DEVICE(0x1199, 0x9013)},	/* Sierra Wireless Gobi 3000 Modem device (MC8355) */
+	{USB_DEVICE(0x1199, 0x9014)},	/* Sierra Wireless Gobi 3000 QDL */
+	{USB_DEVICE(0x1199, 0x9015)},	/* Sierra Wireless Gobi 3000 Modem device */
+	{USB_DEVICE(0x1199, 0x9018)},	/* Sierra Wireless Gobi 3000 QDL */
+	{USB_DEVICE(0x1199, 0x9019)},	/* Sierra Wireless Gobi 3000 Modem device */
+	{USB_DEVICE(0x1199, 0x901b)},	/* Sierra Wireless MC7770 */
+	{USB_DEVICE(0x12D1, 0x14F0)},	/* Sony Gobi 3000 QDL */
+	{USB_DEVICE(0x12D1, 0x14F1)},	/* Sony Gobi 3000 Composite */
+	{USB_DEVICE(0x0AF0, 0x8120)},	/* Option GTM681W */
+
+	/* non-Gobi Sierra Wireless devices */
+	{DEVICE_SWI(0x03f0, 0x4e1d)},	/* HP lt4111 LTE/EV-DO/HSPA+ Gobi 4G Module */
+	{DEVICE_SWI(0x0f3d, 0x68a2)},	/* Sierra Wireless MC7700 */
+	{DEVICE_SWI(0x114f, 0x68a2)},	/* Sierra Wireless MC7750 */
+	{DEVICE_SWI(0x1199, 0x68a2)},	/* Sierra Wireless MC7710 */
+	{DEVICE_SWI(0x1199, 0x68c0)},	/* Sierra Wireless MC7304/MC7354 */
+	{DEVICE_SWI(0x1199, 0x901c)},	/* Sierra Wireless EM7700 */
+	{DEVICE_SWI(0x1199, 0x901e)},	/* Sierra Wireless EM7355 QDL */
+	{DEVICE_SWI(0x1199, 0x901f)},	/* Sierra Wireless EM7355 */
+	{DEVICE_SWI(0x1199, 0x9040)},	/* Sierra Wireless Modem */
+	{DEVICE_SWI(0x1199, 0x9041)},	/* Sierra Wireless MC7305/MC7355 */
+	{DEVICE_SWI(0x1199, 0x9051)},	/* Netgear AirCard 340U */
+	{DEVICE_SWI(0x1199, 0x9053)},	/* Sierra Wireless Modem */
+	{DEVICE_SWI(0x1199, 0x9054)},	/* Sierra Wireless Modem */
+	{DEVICE_SWI(0x1199, 0x9055)},	/* Netgear AirCard 341U */
+	{DEVICE_SWI(0x1199, 0x9056)},	/* Sierra Wireless Modem */
+	{DEVICE_SWI(0x1199, 0x9060)},	/* Sierra Wireless Modem */
+	{DEVICE_SWI(0x1199, 0x9061)},	/* Sierra Wireless Modem */
+	{DEVICE_SWI(0x1199, 0x9062)},	/* Sierra Wireless EM7305 QDL */
+	{DEVICE_SWI(0x1199, 0x9063)},	/* Sierra Wireless EM7305 */
+	{DEVICE_SWI(0x1199, 0x9070)},	/* Sierra Wireless MC74xx */
+	{DEVICE_SWI(0x1199, 0x9071)},	/* Sierra Wireless MC74xx */
+	{DEVICE_SWI(0x1199, 0x9078)},	/* Sierra Wireless EM74xx */
+	{DEVICE_SWI(0x1199, 0x9079)},	/* Sierra Wireless EM74xx */
+	{DEVICE_SWI(0x1199, 0x907a)},	/* Sierra Wireless EM74xx QDL */
+	{DEVICE_SWI(0x1199, 0x907b)},	/* Sierra Wireless EM74xx */
+	{DEVICE_SWI(0x1199, 0x9090)},	/* Sierra Wireless EM7565 QDL */
+	{DEVICE_SWI(0x1199, 0x9091)},	/* Sierra Wireless EM7565 */
+	{DEVICE_SWI(0x1199, 0x90d2)},	/* Sierra Wireless EM9191 QDL */
+	{DEVICE_SWI(0x1199, 0x90e4)},	/* Sierra Wireless EM86xx QDL*/
+	{DEVICE_SWI(0x1199, 0x90e5)},	/* Sierra Wireless EM86xx */
+	{DEVICE_SWI(0x1199, 0xc080)},	/* Sierra Wireless EM7590 QDL */
+	{DEVICE_SWI(0x1199, 0xc081)},	/* Sierra Wireless EM7590 */
+	{DEVICE_SWI(0x413c, 0x81a2)},	/* Dell Wireless 5806 Gobi(TM) 4G LTE Mobile Broadband Card */
+	{DEVICE_SWI(0x413c, 0x81a3)},	/* Dell Wireless 5570 HSPA+ (42Mbps) Mobile Broadband Card */
+	{DEVICE_SWI(0x413c, 0x81a4)},	/* Dell Wireless 5570e HSPA+ (42Mbps) Mobile Broadband Card */
+	{DEVICE_SWI(0x413c, 0x81a8)},	/* Dell Wireless 5808 Gobi(TM) 4G LTE Mobile Broadband Card */
+	{DEVICE_SWI(0x413c, 0x81a9)},	/* Dell Wireless 5808e Gobi(TM) 4G LTE Mobile Broadband Card */
+	{DEVICE_SWI(0x413c, 0x81b1)},	/* Dell Wireless 5809e Gobi(TM) 4G LTE Mobile Broadband Card */
+	{DEVICE_SWI(0x413c, 0x81b3)},	/* Dell Wireless 5809e Gobi(TM) 4G LTE Mobile Broadband Card (rev3) */
+	{DEVICE_SWI(0x413c, 0x81b5)},	/* Dell Wireless 5811e QDL */
+	{DEVICE_SWI(0x413c, 0x81b6)},	/* Dell Wireless 5811e QDL */
+	{DEVICE_SWI(0x413c, 0x81c2)},	/* Dell Wireless 5811e */
+	{DEVICE_SWI(0x413c, 0x81cb)},	/* Dell Wireless 5816e QDL */
+	{DEVICE_SWI(0x413c, 0x81cc)},	/* Dell Wireless 5816e */
+	{DEVICE_SWI(0x413c, 0x81cf)},   /* Dell Wireless 5819 */
+	{DEVICE_SWI(0x413c, 0x81d0)},   /* Dell Wireless 5819 */
+	{DEVICE_SWI(0x413c, 0x81d1)},   /* Dell Wireless 5818 */
+	{DEVICE_SWI(0x413c, 0x81d2)},   /* Dell Wireless 5818 */
+	{DEVICE_SWI(0x413c, 0x8217)},	/* Dell Wireless DW5826e */
+	{DEVICE_SWI(0x413c, 0x8218)},	/* Dell Wireless DW5826e QDL */
+
+	/* Huawei devices */
+	{DEVICE_HWI(0x03f0, 0x581d)},	/* HP lt4112 LTE/HSPA+ Gobi 4G Modem (Huawei me906e) */
+
+	{ }				/* Terminating entry */
+};
+MODULE_DEVICE_TABLE(usb, id_table);
+
+static int handle_quectel_ec20(struct device *dev, int ifnum)
+{
+	int altsetting = 0;
+
+	/*
+	 * Quectel EC20 Mini PCIe LTE module layout:
+	 * 0: DM/DIAG (use libqcdm from ModemManager for communication)
+	 * 1: NMEA
+	 * 2: AT-capable modem port
+	 * 3: Modem interface
+	 * 4: NDIS
+	 */
+	switch (ifnum) {
+	case 0:
+		dev_dbg(dev, "Quectel EC20 DM/DIAG interface found\n");
+		break;
+	case 1:
+		dev_dbg(dev, "Quectel EC20 NMEA GPS interface found\n");
+		break;
+	case 2:
+	case 3:
+		dev_dbg(dev, "Quectel EC20 Modem port found\n");
+		break;
+	case 4:
+		/* Don't claim the QMI/net interface */
+		altsetting = -1;
+		break;
+	}
+
+	return altsetting;
+}
+
+static int qcprobe(struct usb_serial *serial, const struct usb_device_id *id)
+{
+	struct usb_host_interface *intf = serial->interface->cur_altsetting;
+	struct device *dev = &serial->dev->dev;
+	int retval = -ENODEV;
+	__u8 nintf;
+	__u8 ifnum;
+	int altsetting = -1;
+	bool sendsetup = false;
+
+	/* we only support vendor specific functions */
+	if (intf->desc.bInterfaceClass != USB_CLASS_VENDOR_SPEC)
+		goto done;
+
+	nintf = serial->dev->actconfig->desc.bNumInterfaces;
+	dev_dbg(dev, "Num Interfaces = %d\n", nintf);
+	ifnum = intf->desc.bInterfaceNumber;
+	dev_dbg(dev, "This Interface = %d\n", ifnum);
+
+	if (nintf == 1) {
+		/* QDL mode */
+		/* Gobi 2000 has a single altsetting, older ones have two */
+		if (serial->interface->num_altsetting == 2)
+			intf = usb_altnum_to_altsetting(serial->interface, 1);
+		else if (serial->interface->num_altsetting > 2)
+			goto done;
+
+		if (intf && intf->desc.bNumEndpoints == 2 &&
+		    usb_endpoint_is_bulk_in(&intf->endpoint[0].desc) &&
+		    usb_endpoint_is_bulk_out(&intf->endpoint[1].desc)) {
+			dev_dbg(dev, "QDL port found\n");
+
+			if (serial->interface->num_altsetting == 1)
+				retval = 0; /* Success */
+			else
+				altsetting = 1;
+		}
+		goto done;
+
+	}
+
+	/* default to enabling interface */
+	altsetting = 0;
+
+	/*
+	 * Composite mode; don't bind to the QMI/net interface as that
+	 * gets handled by other drivers.
+	 */
+
+	switch (id->driver_info) {
+	case QCSERIAL_G1K:
+		/*
+		 * Gobi 1K USB layout:
+		 * 0: DM/DIAG (use libqcdm from ModemManager for communication)
+		 * 1: serial port (doesn't respond)
+		 * 2: AT-capable modem port
+		 * 3: QMI/net
+		 */
+		if (nintf < 3 || nintf > 4) {
+			dev_err(dev, "unknown number of interfaces: %d\n", nintf);
+			altsetting = -1;
+			goto done;
+		}
+
+		if (ifnum == 0) {
+			dev_dbg(dev, "Gobi 1K DM/DIAG interface found\n");
+			altsetting = 1;
+		} else if (ifnum == 2)
+			dev_dbg(dev, "Modem port found\n");
+		else
+			altsetting = -1;
+		break;
+	case QCSERIAL_G2K:
+		/* handle non-standard layouts */
+		if (nintf == 5 && id->idProduct == QUECTEL_EC20_PID) {
+			altsetting = handle_quectel_ec20(dev, ifnum);
+			goto done;
+		}
+
+		/*
+		 * Gobi 2K+ USB layout:
+		 * 0: QMI/net
+		 * 1: DM/DIAG (use libqcdm from ModemManager for communication)
+		 * 2: AT-capable modem port
+		 * 3: NMEA
+		 */
+		if (nintf < 3 || nintf > 4) {
+			dev_err(dev, "unknown number of interfaces: %d\n", nintf);
+			altsetting = -1;
+			goto done;
+		}
+
+		switch (ifnum) {
+		case 0:
+			/* Don't claim the QMI/net interface */
+			altsetting = -1;
+			break;
+		case 1:
+			dev_dbg(dev, "Gobi 2K+ DM/DIAG interface found\n");
+			break;
+		case 2:
+			dev_dbg(dev, "Modem port found\n");
+			break;
+		case 3:
+			/*
+			 * NMEA (serial line 9600 8N1)
+			 * # echo "\$GPS_START" > /dev/ttyUSBx
+			 * # echo "\$GPS_STOP"  > /dev/ttyUSBx
+			 */
+			dev_dbg(dev, "Gobi 2K+ NMEA GPS interface found\n");
+			break;
+		}
+		break;
+	case QCSERIAL_SWI:
+		/*
+		 * Sierra Wireless layout:
+		 * 0: DM/DIAG (use libqcdm from ModemManager for communication)
+		 * 2: NMEA
+		 * 3: AT-capable modem port
+		 * 8: QMI/net
+		 */
+		switch (ifnum) {
+		case 0:
+			dev_dbg(dev, "DM/DIAG interface found\n");
+			break;
+		case 2:
+			dev_dbg(dev, "NMEA GPS interface found\n");
+			sendsetup = true;
+			break;
+		case 3:
+			dev_dbg(dev, "Modem port found\n");
+			sendsetup = true;
+			break;
+		default:
+			/* don't claim any unsupported interface */
+			altsetting = -1;
+			break;
+		}
+		break;
+	case QCSERIAL_HWI:
+		/*
+		 * Huawei devices map functions by subclass + protocol
+		 * instead of interface numbers. The protocol identify
+		 * a specific function, while the subclass indicate a
+		 * specific firmware source
+		 *
+		 * This is a list of functions known to be non-serial.  The rest
+		 * are assumed to be serial and will be handled by this driver
+		 */
+		switch (intf->desc.bInterfaceProtocol) {
+			/* QMI combined (qmi_wwan) */
+		case 0x07:
+		case 0x37:
+		case 0x67:
+			/* QMI data (qmi_wwan) */
+		case 0x08:
+		case 0x38:
+		case 0x68:
+			/* QMI control (qmi_wwan) */
+		case 0x09:
+		case 0x39:
+		case 0x69:
+			/* NCM like (huawei_cdc_ncm) */
+		case 0x16:
+		case 0x46:
+		case 0x76:
+			altsetting = -1;
+			break;
+		default:
+			dev_dbg(dev, "Huawei type serial port found (%02x/%02x/%02x)\n",
+				intf->desc.bInterfaceClass,
+				intf->desc.bInterfaceSubClass,
+				intf->desc.bInterfaceProtocol);
+		}
+		break;
+	default:
+		dev_err(dev, "unsupported device layout type: %lu\n",
+			id->driver_info);
+		break;
+	}
+
+done:
+	if (altsetting >= 0) {
+		retval = usb_set_interface(serial->dev, ifnum, altsetting);
+		if (retval < 0) {
+			dev_err(dev,
+				"Could not set interface, error %d\n",
+				retval);
+			retval = -ENODEV;
+		}
+	}
+
+	if (!retval)
+		usb_set_serial_data(serial, (void *)(unsigned long)sendsetup);
+
+	return retval;
+}
+
+static int qc_attach(struct usb_serial *serial)
+{
+	struct usb_wwan_intf_private *data;
+	bool sendsetup;
+
+	data = kzalloc_obj(*data);
+	if (!data)
+		return -ENOMEM;
+
+	sendsetup = !!(unsigned long)(usb_get_serial_data(serial));
+	if (sendsetup)
+		data->use_send_setup = 1;
+
+	spin_lock_init(&data->susp_lock);
+
+	usb_set_serial_data(serial, data);
+
+	return 0;
+}
+
+static void qc_release(struct usb_serial *serial)
+{
+	struct usb_wwan_intf_private *priv = usb_get_serial_data(serial);
+
+	usb_set_serial_data(serial, NULL);
+	kfree(priv);
+}
+
+static struct usb_serial_driver qcdevice = {
+	.driver = {
+		.name      = "qcserial",
+	},
+	.description         = "Qualcomm USB modem",
+	.id_table            = id_table,
+	.num_ports           = 1,
+	.probe               = qcprobe,
+	.open		     = usb_wwan_open,
+	.close		     = usb_wwan_close,
+	.dtr_rts	     = usb_wwan_dtr_rts,
+	.write		     = usb_wwan_write,
+	.write_room	     = usb_wwan_write_room,
+	.chars_in_buffer     = usb_wwan_chars_in_buffer,
+	.tiocmget            = usb_wwan_tiocmget,
+	.tiocmset            = usb_wwan_tiocmset,
+	.attach              = qc_attach,
+	.release	     = qc_release,
+	.port_probe          = usb_wwan_port_probe,
+	.port_remove	     = usb_wwan_port_remove,
+#ifdef CONFIG_PM
+	.suspend	     = usb_wwan_suspend,
+	.resume		     = usb_wwan_resume,
+#endif
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+	&qcdevice, NULL
+};
+
+module_usb_serial_driver(serial_drivers, id_table);
+
+MODULE_AUTHOR(DRIVER_AUTHOR);
+MODULE_DESCRIPTION(DRIVER_DESC);
+MODULE_LICENSE("GPL v2");