_timer_start_oneshot_after kills my application

[MQXuser]

I would like to know the reason the following code results in INTERRUPT STACK OVERFLOW.

The function is an Edge Triggered Interrupt and problem comes when I try to start a one shot timer.

Timer component is created before with priority 3 and 2000 stack. I have a periodic timer running and 4 interrupts (Edge Triggered Interrupts) can start another timer each. Therefore, I can have 5 timers running at the same time. Problem comes when trying to create the first timer within an interrupt.

static void CleanWiegandDoor1(_timer_id timer_id,pointer event_ptr,uint_32 seconds,uint_32 milliseconds){
     Door1Counter = 0;
}

void DMA_T0_ISR(pointer dummy_param){   if(!Door2Counter){
    _timer_start_oneshot_after( CleanWiegandDoor2, 0 , TIMER_KERNEL_TIME_MODE, 50 );   }   Door2Counter++;   if(Door2Counter >= WiegandBitQty){       Door2Counter = 0;      FifoInsertDataID(codeReadD2, 2); //Codigo y La Puerta      codeReadD2 = 0;   }   DTIM_clr_flag(0);   return;}

 Regards

[MQXuser]

Okay, I will reorder my question.

How can I start a timer from an interrupt?

[MQXuser]

I am at the point where I need to solve this problem. How to start a timer from an interrupt?. Are there logical reasons that prevent my application to use the instruction mentioned into a ISR that I have created?

[EAI · Accepted solution]

You can't start a timer from an ISR. The timer component uses a semaphore internally -  _time_start waits on the semaphore. You can't wait on a semaphore from an ISR, so therefore you can't call _timer_start from an ISR.

[MQXuser]

I though I could call that function since it is not specifically mentioned in the list of

"3.10.3.2 Functions That ISRs Should Not Call "

Thank you,

[EAI]

Yes, it should also be documented under traits, but is not. 

It has been reported to the development team.

Message Edited by EAI on 2009-10-09 11:58 PM