busdma [was: Re: svn commit: r208850 - projects/ppc64/sys/powerpc/include]

[Marcel Moolenaar]

[about unifying busdma implementations]

On Jun 6, 2010, at 1:06 AM, Scott Long wrote:

>> Can you send me whatever you have or have done before so that I
>> can leverage.
>> 
> 
> I struggle with answering the question of whether to just reorg the interface definitions but leave the interface alone, or whether to rewrite the interface definitions in the context of having a new DMA api.

*snip*

I understand. All I can say is that when 90-95% of busdma is MI code and you
only have a few MD functions, interface redesigns are a lot easier to manage
and much less time-consuming to implement and test.

I have an interest in busdma/mi, simply because it allows me add a feature to
ia64 in a way that benefits all platforms and as such makes the work useful
even if I have to abandon ia64 altogether. If busdma/mi ends your struggle and
starts your work on busdma/ng, then I'm fine with that too. Then busdma/mi was
still useful, just in a different way. Maybe busdma/ng cannot really happen
without having busdma/mi first...

-- 
Marcel Moolenaar
xcllnt at mac.com