Re: [Xpert] Re: [rtl] Re: Virge DX and accel. introduced latency? (was Re: [Xpert]XFree86in realtime applications)

[Mark Vojkovich]

On Sun, 26 Nov 2000, Kevin Brosius wrote:

> 
> I suppose we could add an option, something like 'early_sync'  (or maybe
> something more descriptive) which changes the accelerator sync behavior
> in 4.0.x drivers to make them behave more like 3.3.6.  I'd be willing to
> make a trial s3virge driver with a change like this so you could test
> it.

   I think the biggest problem is that color expansion data with
the Virge driver is *always* sent to the hardware without making
sure there is enough room in the fifo for it.  The engine seems
to be designed to rely on retries for this type of operation. 

> 
> Mark,
>   I'm thinking of adding AccelSync commands to all the Subsequent
> accelerated primitives and enabling them on an option.  That should get
> us close to the 3.3.6 architecture in a switchable way.


   All the rest of the routines seem to be waiting for the fifo
just fine.  I expect you'd get rid of most of the symptoms by
just disabling color expansion.


                                        Mark.

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