Trouble with cdc_mbim mode LTE module

[seongkeunjin]

Hi. I tried to attach Telit LN940 LTE module to i.MX6Q-SABRE.

I modified kernel just for adding PID and VID of LN940.

The device is installed well. But when I try "ifconfig wwan0 up", the kernel shows below debug messages.

What's going on my board? Please help me.

==========================================================================================

root@imx6qpdlsolox:~# ifconfig wwan0 up
8021q: adding VLAN 0 to HW filter on device wwan0
root@imx6qpdlsolox:~# ------------[ cut here ]------------
WARNING: CPU: 2 PID: 0 at net/sched/sch_generic.c:316 dev_watchdog+0x248/0x24c
NETDEV WATCHDOG: wwan0 (cdc_mbim): transmit queue 0 timed out
Modules linked in: ipu_bg_overlay_sdc ipu_still v4l2_int_device ipu_prp_enc ipu_csi_enc ipu_fg_overlay_sdc
CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.9.11 #2
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[<8010ec88>] (unwind_backtrace) from [<8010b27c>] (show_stack+0x10/0x14)
[<8010b27c>] (show_stack) from [<803e7ed8>] (dump_stack+0x78/0x8c)
[<803e7ed8>] (dump_stack) from [<80132e64>] (__warn+0xe8/0x100)
[<80132e64>] (__warn) from [<80132eb4>] (warn_slowpath_fmt+0x38/0x48)
[<80132eb4>] (warn_slowpath_fmt) from [<8081a3b4>] (dev_watchdog+0x248/0x24c)
[<8081a3b4>] (dev_watchdog) from [<801869b8>] (call_timer_fn.constprop.2+0x28/0x98)
[<801869b8>] (call_timer_fn.constprop.2) from [<80186ac0>] (expire_timers+0x98/0xa4)
[<80186ac0>] (expire_timers) from [<80186b64>] (run_timer_softirq+0x98/0x18c)
[<80186b64>] (run_timer_softirq) from [<80137854>] (__do_softirq+0xe8/0x234)
[<80137854>] (__do_softirq) from [<80137c6c>] (irq_exit+0xcc/0x108)
[<80137c6c>] (irq_exit) from [<8017611c>] (__handle_domain_irq+0x80/0xec)
[<8017611c>] (__handle_domain_irq) from [<801014f0>] (gic_handle_irq+0x48/0x8c)
[<801014f0>] (gic_handle_irq) from [<8010bd8c>] (__irq_svc+0x6c/0xa8)
Exception stack(0xa80a9f68 to 0xa80a9fb0)
9f60: 00000000 00000002 00000001 a80a8000 5d3d3cc0 00000011
9f80: ab715e28 00000001 78f291fb 00000011 00000004 80f03144 00000000 a80a9fb8
9fa0: 809c10a4 806d1810 20070013 ffffffff
[<8010bd8c>] (__irq_svc) from [<806d1810>] (cpuidle_enter_state+0x17c/0x29c)
[<806d1810>] (cpuidle_enter_state) from [<8016cde4>] (cpu_startup_entry+0x148/0x218)
[<8016cde4>] (cpu_startup_entry) from [<101015cc>] (0x101015cc)
---[ end trace 1b4586badbc71aa0 ]---

[weidong_sun]

Hi, Jin,

    Your porting method is not correct, 4G's porting is very similar to 3G, please refter to the link:

How to add 3G modem in Sabresx board 

IMX6SL EVK with 3G USB dongle (Huawei-EM770) 

https://community.nxp.com/docs/DOC-328353 

Have a nice day!

Best regards,

Wedong sun