I am trying to develop my own DMA driver for Xeon Phi. The first attempt seems to work quite well. I tried to use the dstat_wb feature. However, if I try to write an address into the dstat_wb_lo and dstat_wb_hi registers the channel results in an error state when I set the descriptor ring:
Channel error register is 0x20000000. What does this bit mean?
Do I have to write another bit in the channel control register?
The Linux driver writes this register if model=KNC and stepping >= B0. I have a KNC and the stepping value reads 3.