Regarding McBSP Int ...help needed...

Regarding McBSP Int ...help needed...

[Raghu_Mallya]

Hi:

Although not a very Linux oriented question, many of you have already
worked on this... I am facing a problem as below..

Overview
********
I am using DSP gateway for intercommunication process between ARM and
DSP in OMAP5910(custom Board). On the DSP side I am trying to read the
data from the external PCM  through McBSP1 and trying to send the
receiving data to ARM using DSP gateway.

Problem
********
I am getting the first interrupt in the McBSP1 properly. But after this
my ISR dies off ie becomes inactive. I am not able to get any
interrupts.. My ISR code is as below


Void McBSPRxInterrupt(Void)
{   
      Uns McBSP1Data;
     Uns InterruptStatus; 
      
      //code to check if the interrupt is from McBSP1 or McBSP3
     InterruptStatus = inw(_LEV2_SIR_FIQ);
     
     if(InterruptStatus & 0x0002)
     {
      
	  McBSP1Data = inw(_MCBSP1_DRR1); // copy contents of McBSP
receive
//register to variable
      
	}
	
}

As given in the Omap Manual the int mask get unmasked as soon as we read
the SIR_FIQ register...  Am I doing some mistake...??? PLz help

Regards

Raghu


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Re: Regarding McBSP Int ...help needed...

[Matthew Percival]

G'Day,

> Void McBSPRxInterrupt(Void)
> {   
>       Uns McBSP1Data;
>      Uns InterruptStatus; 
>       
>       //code to check if the interrupt is from McBSP1 or McBSP3
>      InterruptStatus = inw(_LEV2_SIR_FIQ);
>      
>      if(InterruptStatus & 0x0002)
>      {
>       
> 	  McBSP1Data = inw(_MCBSP1_DRR1); // copy contents of McBSP
> receive
> //register to variable
>       
> 	}
> 	
> }

	It looks like you have the start right, but the end is missing
something.  Here is an ISR from my DSP code:

void level21_handler(Arg arg)
{
	MdUns irq = read_reg(DSP_L21_SIR_FIQ);
	timer_handler();
	write_reg(read_reg(DSP_L21_CONTROL) | NEW_FIQ_AGR, DSP_L21_CONTROL);
}

	You need to write NEW_FIQ_AGR to DSP_L20_CONTROL (L2.0 for McBSP; L2.1
here because it is a GPTimer) at the end of your ISR.  If I am
remembering correctly, this tells the Interrupt module that you have
completed servicing the current interrupt, and for it to calculate the
next interrupt to be serviced.  This is in a 5912, but there should be
something equivalent in the 5910.

	-- Matthew