On Wed, 2008-04-30 at 11:02 -0500, Scott Wood wrote:
On Wed, Apr 30, 2008 at 05:34:56PM +0200, Joakim Tjernlund wrote:
On Wed, 2008-04-30 at 10:21 -0500, Scott Wood wrote:
On Wed, Apr 30, 2008 at 05:11:09PM +0200, Joakim Tjernlund wrote:
Yet the in_bex()/out_bex() functions in PowerPC linux uses sync and all SOC drivers are encouraged to use them. What a waste :(
sync is needed in some of the cases, to sync I/O accesses with DMA buffer accesses. Ideally, we could trust the driver writers to put synchronization in where needed, but it seems Linux has too much x86 heritage for that.
Perhaps, is sync needed in this case for non-smp too? or is eieio enough?
Yes, sync is needed -- eieio doesn't order between stores to cacheable memory and stores to cache-inhibited memory.
OK, thanks
Anyway, just have a look at ucc_geth
Do I have to? :-)
Yes, it needs a little love here and there :) Especially Timur, his little "rename the tx/rx clock" trick costed me a few days :)
Jocke