Query on kernel crash

Uncategorized
1

Hi Team,

I am seeing a kernel crash with below dumps. Wondering if there is any know issue or patch available. This is on 2.6 kernel, qmisdk (04.00.11) with gobi-net_2.50, with EM7565 module .

2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] Unhandled kernel unaligned access[#1]:
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] Cpu 0
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] $ 0 : 0000000000000000 0000000000000001 0000000000000000 0000000000000000
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] $ 4 : 0000000000000010 0000000000000001 0000000000000000 ffffffff8523e1cf
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] $ 8 : 0000000000000000 312f312d312f312d 312e342f312d312e 343a312e332f6570
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] $12 : 0000000010008ce1 000000001000001e ffffffff80336450 0000000000000000
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] $16 : a800000003553ad0 ffffff0000000000 ffffffffdc5e0008 2aded09ccdfbe639
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] $20 : a800000004aa2850 a800000003484a80 a800000004aa2850 000000002b2fdbf0
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] $24 : 0000000000000001 ffffffff80484288
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] $28 : a800000003550000 a800000003553aa0 000000002b39d040 ffffffff80100c04
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] Hi : 0000000000000000
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] Lo : 0000000000000000
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] epc : ffffffff8025dd18 do_ade+0x2b8/0x5c0
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] Tainted: P
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] ra : ffffffff80100c04 ret_from_exception+0x0/0x10
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] Status: 10008ce3 KX SX UX KERNEL EXL IE
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] Cause : 00800010
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] BadVA : 2aded09ccdfbe639
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] PrId : 000d0601 (Cavium Octeon+)
2026 Sep 11 07:36:46+00:00 wglng-8193 kernel [warning] Modules linked in: lm75 pca953x ftdi_sio core429(P) usbnet GobiSerial GobiNet crc_ccitt ppp_async ppp_mppe ecb arc4 bsd_comp ppp_deflate
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] Process slqssdk (pid: 14910, threadinfo=a800000003550000, task=a80000000354ceb8, tls=000000002b3a57d0)
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] Stack : ffffffff80f42590 a8000000042777c0 ffffffff85240000 a800000003484a80
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] a800000002077c20 ffffffff80100c04 0000000000000000 0000000000000001
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] 2aded09ccdfbe631 0000000000000000 0000000000000000 0000000000000001
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] 0000000000000000 ffffffff8523e1cf 0000000000000000 312f312d312f312d
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] 312e342f312d312e 343a312e332f6570 a800000410000500 ffffffff8010605c
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] ffffffff80336450 0000000000000000 a8000000042777c0 ffffffff85240000
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] a800000003484a80 a800000002077c20 a800000004aa2850 a800000003484a80
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] a800000004aa2850 000000002b2fdbf0 0000000000000001 ffffffff80484288
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] a800000004aa2850 ffffffff80f30000 a800000003550000 a800000003553c30
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] 000000002b39d040 ffffffff803a1624 0000000010008ce3 0000000000000000
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] …
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] Call Trace:
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] [] do_ade+0x2b8/0x5c0
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] [] ret_from_exception+0x0/0x10
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] [] sysfs_open_file+0xa0/0x440
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] [] __dentry_open+0x2f4/0x448
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] [] do_filp_open+0x77c/0xc30
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] [] do_sys_open+0x7c/0x1f0
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] [] handle_sysn32+0x44/0x84
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning]
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning]
2026 Sep 11 07:36:47+00:00 wglng-8193 kernel [warning] Code: 00431024 1440fff1 00000000 <6a630000> 6e630007 24020000 14400034 0060982d 8e020124
2026 Sep 11 07:36:50+00:00 wglng-8193 kernel [warning] usb_control_msg failed (-145)
2026 Sep 11 07:36:50+00:00 wglng-8193 kernel [warning] Write URB timeout, cnt(1)
2026 Sep 11 07:36:50+00:00 wglng-8193 kernel [warning] usb_control_msg failed (-145)
2026 Sep 11 07:36:50+00:00 wglng-8193 kernel [warning] Write URB timeout, cnt(1)
2026 Sep 11 07:36:51+00:00 wglng-8193 kernel [warning] usb_control_msg failed (-145)
2026 Sep 11 07:36:51+00:00 wglng-8193 kernel [warning] Write URB timeout, cnt(2)
2026 Sep 11 07:36:51+00:00 wglng-8193 kernel [warning] usb_control_msg failed (-145)
2026 Sep 11 07:36:51+00:00 wglng-8193 kernel [warning] Write URB timeout, cnt(2)
2026 Sep 11 07:36:51+00:00 wglng-8193 kernel [warning] usb_control_msg failed (-145)
2026 Sep 11 07:36:51+00:00 wglng-8193 kernel [warning] Write URB timeout, cnt(3)
2026 Sep 11 07:36:51+00:00 wglng-8193 kernel [warning] usb_control_msg failed (-145)
2026 Sep 11 07:36:51+00:00 wglng-8193 kernel [warning] Write URB timeout, cnt(3)

2

Maybe you can try the latest slqssdk and gobi driver

3

Hello,

I checked the above latest driver and SDK. Unfortunately there is lot of changes with our current Gobi driver version. I have query on QMI_CONTROL_MSG_DELAY_MS in QMIDevice.h file. Can I have higher value , say 200 ms instead of 100 ms? Looks like it can affect the system during initialization as well as Run time.

5

Probably you need to make some test on your platform to verify

6

Tested with 200 ms and saw runtime kernel crash with random time. Sometime in 4 hours , some time after 1 hour. with 100 ms no issue with Runtime but failing sometime during initialization with MAX_RETRY as 5. Probably keeping the same 100 ms for delay and increase MAX_RETRY to 10 is a better approach?

7

You can use linux command to reattach usb port

https://stackoverflow.com/questions/21580750/disconnect-and-reconnect-ttyusb0-programmatically-in-linux

8

The /dev/qcqmi end point is not creating in the failed case during initialization. If we add more delay, it get created.

9

As you say, adding delay will lead to crash issue.
So better to use origjnal timing

Once initialization is failed, reattach the usb port by the linux command

10

Thank you , will try that.

11

if initialization fails (modem detection fails) , /dev/qcqmi node is not created. Are you saying to create it /dev/qcqmi with linux command?

12

I am saying to reattach usb port

See below as example

e.g.

echo '3-2' | sudo tee /sys/bus/usb/drivers/usb/unbind
echo '3-2' | sudo tee /sys/bus/usb/drivers/usb/bind
13

Hello jyijyi,

Are you saying the crash with adding 100ms more delay for CONTROLMSG_DELAY is a know issue? Do we have any past known issue with kernel crash with increase in delay ?

14

no, i don’t know if this is known issue
but as you said that using 100ms has no issue in runtime, so you can use this value.

15

thank you. I was checking the timeout value in the latest SDK releases and it is the same as 100ms.

16

Hello,

It looks like with CONTROL_MSG_DELAY set to 200 ms, the race condition is exposed and the memory corruption happening.

17

Then it seems better to use the original 100ms

18

are you saying that if it break for 200 ms, go back to 100 ms without fixing the issue we see with 200 ms?

19

i still don’t understand why you need to change this value in the driver…

20

During bootup initialization phase, sometimes, modem was taking long time to negotiate DATA Format and control Sync messages with Driver ( Even Retry did not worked). When we changed to 200ms it is fixed but sometime we came into this Run time crash issue. Now we are putting back the 100ms Run time and adding another delay of 200 ms for all the control message needed only during initialization.

21

I would suggest you take the original code, if the retry does not work, just simply reattach the USB by the following commands:

e.g.

echo '3-2' | sudo tee /sys/bus/usb/drivers/usb/unbind
echo '3-2' | sudo tee /sys/bus/usb/drivers/usb/bind