Dan Malek writes: > As I mentioned in the first message, I suspect the problem is with the > multiple mapping/access of data in the pinned and remapped areas. Linux > tends to allocate memory from the high end down, so if you consistent_alloc() > some space on large memory systems, you are just remapping the attributes > of a page. If you do this on memory that is also covered by a large page, > sometimes you will get the access through this large page, and others through > an alternate mapping, which I believe confuses the MMU/cache with different > attributes (which I was assured wouldn't cause problems on 4xx).
We have reproduced the problem using a ramdisk root and loopback, with the ethernet disabled, so the only I/O device that is active is the serial port, which doesn't use DMA. So it doesn't look like it is anything to do with DMA or with consistent_alloc. Paul. ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
