Peter Hurley wrote: > Quadlet reads to memory above 4GB is painfully slow when serviced > by the AR DMA context. In addition, the CPU(s) may be locked-up, > preventing any transfer at all.
Using physical DMA prevents the use of that address space for software address handlers, so you have adjust the low_memory_region start in core-transaction.c. > Write the PhyUpperBound register with the end-of-memory value. If > end-of-memory is beyond the OHCI limit of 0x0000ffff00000000, > clamp to that value. You will have to lower this limit; there are protcols that assume that addresses like 0xecc000000000 are available for software. Regards, Clemens -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/