Hi Steve, > Has anyone attempted to use the internal 8xx IDMA controller to do > DMA to a IDE disk? I'm considering making an attempt at it, but I just > want to hear first if anyone has tried already and if so what the > experience is.
I did last summer. Well actually I tried. It wasn't too hard to use the IDMA to transfer data from/to ide disk. But at that time my code just started polling after setting up the dma. So the cpu was busy waiting instead of doing something useful. But I reckon it's not to hard to use irqs for signaling the end of DMA transfer to the ide driver. I noticed that the cycle time of the normal (i.e. two-address) IDMA mode is huge. So the performance wasn't great. I have to pick up that work again now. So I wonder if you or anybody else has done something on this topic? Thanks, Steven ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
