Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

Setting up a DMA Transaction in a driver

Hello everyone, i currently working on driver, where i need to do some dma-transaction. I can do DMA and PIO directly on the Nios 2 System, without Linux ( withot an running system Linux Ker...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
20 years ago

Hi Helmar,

> get_dma_residue((unsigned int)0);

>

> it returns -1,

<<snip>>

> this means MAX_DMA_CHANNELS is at least 0

Indeed! Check your dma.o with objdump ... each entry in dma_channels should account

for 0x38 bytes (which I confirmed in my own kernel build -- it&#39;s ok). Although I haven&#39;t

actually used the dma in the kernel yet -- sorry.

If your table is in fact length zero, you might want to touch your nios2_system.h

(or dma.c).

Regards,

--Scott