Recently our product have developed a nasty habbit of throwing a kernel panic just after we attach an USB cable to the OTG port. The log we get at the serial terminal when this happens looks something like this:

[  220.992095] gpio_check_and_wake: wake-n_gpio77 STATE=WAKEUP
[  221.013703] gpio_check_and_wake: wake-n_gpio77 STATE=SLEEP
[  229.971921]
[  229.971921] Apps Watchdog bark received - Calling Panic
[  229.977628] Kernel panic - not syncing: Apps Watchdog Bark received
[  229.977628]
[  229.985380] CPU: 0 PID: 534 Comm: qmuxd Not tainted 3.14.30ltsi-yocto-standar                                                                                                     d #4
[  229.992888] [<c0015690>] (unwind_backtrace) from [<c001279c>] (show_stack+0x2                                                                                                     0/0x24)
[  230.000579] [<c001279c>] (show_stack) from [<c056d934>] (dump_stack+0x20/0x28                                                                                                     )
[  230.007782] [<c056d934>] (dump_stack) from [<c056cf18>] (panic+0x98/0x1e4)
[  230.014619] [<c056cf18>] (panic) from [<c004b4d0>] (msm_wdog_bark_fin+0x28/0x                                                                                                     30)
[  230.022035] [<c004b4d0>] (msm_wdog_bark_fin) from [<ffff12c8>] (0xffff12c8)
[  230.128826] Rebooting in 5 seconds..
[  235.125194] Going down for res4Android Bootloader - UART_DM Initialized!!!
[10] ERROR: No misc partition found
[    0.000000] Kernel is starting...
[    0.000000] Booting Linux on physical CPU 0x0

Can anyone shed some light on what happens and what we might be able to do about it.

Kind regards


hi @andcor,
can you give more information regarding the target? which module is it , and which legato version is inside?
Could you please if possible, attach a complete log with the backtrace and with what happens before?


It is a WP7502 with a custom version of yocto and legato based on version 16.1.

But it seems that it might have been a single device having the issue and that device have just been reworked as its connection to ground were broken. It does not show this issue any more, so I’m tempted to blame a possible shady ground connection for being to fault for this.

I will close this issue for know hoping that we wont see it again.