I am working on EDMA ATM as well. I was curious if you could write a little 
bit about how you are initializing the channels and setting up the 
transfers. Are you writing a kernel module for this and interfacing to it 
in user-space? 

Appreciate any insight, having a hard time digging up info on using EDMA on 
the Beaglebone

On Thursday, November 7, 2013 10:06:53 AM UTC-5, [email protected] wrote:
>
> Greeting again everyone!.
>
> I am using beaglebone with angstrom.
>
> I am trying( by writing a kernel module ) to loop two dma channels 
> together but i cant figure out how....
>
> Here is what i want. i want the completion of the 1st channel to trigger 
> the final interrupt(callback1) and also channel 2.
> and at the completion of channel 2 to trigger the final interrupt 
> (callback2) and also channel 1. etc... creating a loop between ch1 and ch2.
>
> By linking the channels it seems that i cant  link channel 2 back to 
> channel 1. (
>
> edma_link(ch1, ch2);
> edma_link(ch2, ch1);  system fail.
>
> i can only link ch2 on its self 
>
> edma_link(ch1, ch2);
> edma_link(ch2, ch2);  
>
> but i dont want that.
>
> By chaining the final interrupt is not going off. so i dont want that 
> either.
>
> I tried to link  edma_link(ch1, ch2) then chain ch2 with a ch3 and 
> have edma_link(ch3, ch1);  
>
> but then ch1 callback1 returns DMA_CC_ERROR with its paramset being NULL 
> (so the error is from that).
>
> Any suggestions ? 
>

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