Hello ashley, Tuesday, June 06, 2006, 7:37:35 PM, you wrote: aj> I guess your 25 bit dma address field will be word alligned, so ur dma engine will be able to index up to 64 MB( 25+2 = 27 bits). Address not aligned - if I don't do anything driver work incorrect! aj> * dont give whole 64 MB to linux, give only Lower 32 MB. You mean with command line kernel option? If so - I already did so to get all work! aj> * Give only upper 32 MB to linux, and give memory to ur dma engine from lower 32 MB, and once you recv any data you copy to skb and submit to linux. ( ofcourse your performance will get hit aj> in this case.) How can I do this? I have variant that if addres is upper than 32Mb then copy skbuffer to previously allocated memory that lower than 32Mb, but perfomance is wery Important. Maybe you mean this??