On 1/17/2012 2:22 PM, Linus Walleij wrote:

Basically the driver using the dmaengine shall map/unmap buffers
used for slave transfers, not the driver.

I usually map them before setting up a transfer and unmaps them
when egtting the callback from the DMA engine that the transfer is
complete.

You implemented similar stuff in amba-pl08x :) .

if (!plchan->slave)
	pl08x_unmap_buffers(txd);

Why do you want to do this?

This is because people can pass in flags which are
DMA_COMPL_SKIP_SRC_UNMAP, etc.

If they are not passed, then DMA driver must do it for them.

Sorry if i am understanding the DMA logic incorrectly.

-- 
viresh