CPU Cache and busdma usage in USB

Piotr Zięcik kosmo at semihalf.com
Wed Jul 8 10:16:43 UTC 2009

Wednesday 08 July 2009 11:03:43 Hans Petter Selasky napisał(a):
> And what about my patch suggestion in my previous e-mail having the same
> subject. Does it work?

I have tested it and it does not work. By the way Writeback before Writeback 
Invalidate did not change cache behaviour too much. Writeback invalidate 
means flush all modified cache lines and then invalidate cache.

However looking into logs which I have sent you yesterdat I see one difference 
which may be significant. My patch changes Invalidate into Writeback 
Invalidate. In original code if driver write something to memory and then 
invalidate cache, the write will be lost. With my patch after change will
be written to memory and then cache will be invalidated. What do you think ?

Best Regards,
Piotr Ziecik

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