On 03/27/2015 10:22 PM, Russell King - ARM Linux wrote:

On Fri, Mar 27, 2015 at 02:26:52PM +0200, Peter Ujfalusi wrote:

quoted

Do not direct map the virtual channels to sDMA request number. When the
sDMA is behind of a crossbar this direct mapping can cause situations when
certain channel can not be requested since the crossbar request number
will no longer match with the sDMA request line.
The direct mapping for virtual channels with HW request lines will make it
harder to implement MEM_TO_MEM mode for the driver.

There's no point having 127 virtual DMA channels then... is there?
We might as well reduce the number down to a more reasonable set
rather than wasting memory.

I was also come to the same conclusion. My plan was to change the virtual DMA
channels to the same as the sDMA's logical channels.

quoted

@@ -1049,7 +1050,6 @@ static int omap_dma_chan_init(struct omap_dmadev *od, int dma_sig)
 		return -ENOMEM;
 
 	c->reg_map = od->reg_map;
-	c->dma_sig = dma_sig;

That's the only user of dma_sig in this function.  Why not remove it from
the function prototype and its caller?

-- 
P?ter