Writing to settings (non-volatile memory) causes GPIO interrupt triggering losses

Question

SDK 2.1.0 
 nRF9160 
 
 Hi, 
 I recently configured a GPIO input in my project with an associated interrupt whenever it detects a high to low transition. The transition is externally generated every 20ms. 
 With each interruption, a work is rescheduled. 
 
 Everything works as expected until there is a great write (buffer[3500]) to the Settings. 
 After writing, the work is executed, meaning that the transition was not detected. 
 
 It seems to me that it's a problem of priorities... 
 I wanted to know if it is possible, and how, to change the priority of GPIO interrupts. 
 
 Regards, 
 Ricardo

Edvin · Accepted Answer

Ok, I understand. So while you are performing the flash operation, no interrupts are forwarded to your application, and when the write is done, you will get one interrupt (50.761), which is the queued up interrupt, and then it will presume as normal from 50.764 (until the next flash operation). 
 
 What kind of work is it that you are rescheduling on the GPIO interrupt? 
 The thing is that when you are performing flash write operations, the CPU is occupied, so it is not possible to do anything else at that point in time. 
 
 How time sensitive is the work you are rescheduling. It could be possible to limit the amount you write to flash (but do it more often), so that it doesn't take 90ms. But unless you time it to happen directly after a cross detection, it may still block your interrupt from triggering exactly when it occurs. However, if only one interrupt happens while you are writing to flash, this interrupt will be forwarded to the CPU (your application) when the flash write is done. 
 
 Alternatively, it is possible to do some tricks using DPPI to count the number of cross detections while the flash write operations are ongoing, and then catch up with the work once the flash write operation is done. Let me know what you think. 
 
 Best regards, 
 Edvin

Writing to settings (non-volatile memory) causes GPIO interrupt triggering losses

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