[PATCH 7/8] dmaengine/dw_dmac: Unmap all memory buffers after completion of slave transfers

[Russell King - ARM Linux]

On Tue, Jan 17, 2012 at 02:37:10PM +0530, Viresh Kumar wrote:
> 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);

Take a look at that.  "If *NOT* slave, unmap the buffers".  That is in
keeping with what I've been saying.  Slave transfers *do* *not* get
automatic buffer unmapping.