On Fri, 30 Sep 2005 14:22:18 +0100
Alex Zeffertt [off-list ref] wrote:

Till now I have worked around this problem by calling
dcache_invalidate_range() and dcache_flush_range() before and after
accesses to these areas.  I'm now considering changing to Kalle's
way of doing it.

Are there any drawbacks to this approach?

To answer my own question: yes there is a drawback.

I've just done some performance tests on my driver.  In the first
test the driver uses invalidate/flush calls to keep the cache
coherent. In the second test I just use Kalle's mod to setbat().

In the second test the perfomance of the driver is roughly 1/3 of the
performance in the first test.

What I really want is a way of asserting GBL whenever the CPM accesses
ANY memory area other than DPRAM.  Hm.

Alex