Watchdog reset during bootloader dfu

Question

Hello, 
 I am working on using the open_bootloader with our application and running into a problem. 
 We are using the GP_REG to jump from our application back to the bootloader to perform DFU, Our application uses the watchdog timer upon for monitoring It appears that if we attempt to jump back to the bootloader for DFU the watchdog continues to run and hard resets the board as soon as the bootloader starts. I know that is what is causing the reset in the bootloader because if we don't start the watchdog in our application there is no issue performing DFU. 
 I saw this post https://devzone.nordicsemi.com/f/nordic-q-a/3143/how-to-disable-the-wdt-watchdog-timer and attempted to do the same with no success. 
 I guess my question are: 
 1- Is there a way to disable the watchdog in our application before we attempt the DFU? 
 2- Is there a way to configure the open_bootloader to utilizes the watchdog or do we have to create our own bootloader? 
 Thanks 
 Omid

Einar Thorsrud · Answer

Hi Omid, 
 OmidAthari said: When I say the bootloader hangs I mean it seems to remain stuck in the "loop_forever()" function. Nothing else even the led_soft_blink is not happening at that point. 
 I suspect (though I am not sure) that the issue you are seeing is related to a bug in the bootloader, which does not handle a special case with the WDT and LFCLK. If the WDT is active and a soft reset occurs, the WDT will ensure that the LFCLK is kept active. However, the clock is only distributed to the WDT in this case, and not to other "users" of the LFCLK. So this would also explain why you do not see LED blinking etc. In this case the LFCLKSTAT will indicate that the clock is running (which is correct), and that will cause the bootloader to not start it in this code snippet from timer_init() in <SDK 16>\components\libraries\bootloader
rf_bootloader_dfu_timers.c: 
 if (!nrf_clock_lf_is_running())
 {
 nrf_clock_task_trigger(NRF_CLOCK_TASK_LFCLKSTART);
 } 
 Triggering the start task would fix this issue, so this should be rewritten as just: 
 nrf_clock_task_trigger(NRF_CLOCK_TASK_LFCLKSTART); 
 Do you still see the same issue after doing this?

Watchdog reset during bootloader dfu

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