Setting up a DMA Transaction in a driver

Hi Scott,

thanks you for answer.

According to your suggestion

<div class='quotetop'>QUOTE </div>

--- Quote Start ---

Check the name of your dma controller in SOPCBuilder ...[/b]

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i checked it:

- the name of the DMA controller in the SoPC Builder is correct: dma_0

- in the nios2_system.h file of my Kernel Build, there is na_dma_0

- in the kernel i have enabled DMA Support

- in the proc filesystem i have an dma entry, if i use

cat dma

its empty.

it seems there is still something wrong. For a little in my driver code i used

i=get_dma_residue((unsigned int)0);

it returns -1,

according to the driver code in arch/nios2nommu/kernel/dma.c

nt get_dma_residue(unsigned int dmanr)
{
    int result =-1;
    if (dmanr < MAX_DMA_CHANNELS) {
  result = inl(dma_channels.addr+REG_DMA_LENGTH);
    }
    return result;
}

this means MAX_DMA_CHANNELS is at least 0, since dmanr is 0,

so something is wrong in

#define MAX_DMA_CHANNELS    sizeof(dma_channels)/sizeof(struct dma_channel)

but this again depends on the definition on the the table, as you have written in your post.

Any idea?

Thanks.

Helmar

-- according to the kernel bug. the function i used isn&#39;t implemented