> I don't think "normal" drivers do them at all. I did experiment with > DirectFB at one point and had it place all offscreen surfaces to AGP > memory. It worked really well on my hardware (G400 + VIA KT133 > northbridge). I also tried it with PCI transfers and that too worked but > was naturally slower. I'd like to make DirectFB use AGP again since 32MB > of video memory isn't always enough. > > > (Which is interesting, that means that if we want to copy something out > > of video memory, we can't write it to AGP memory and then read it, we > > need to actually do the blit from the CPU, good to know for our memory > > manager. That also means that we have a problem if the video memory > > isn't entirely accessible by the CPU ...) > > What about PCI master writes? Are there bridges that don't support even > those?
Usually, those work. I have a list of errata of Apple bridges at least in Darwin, some do not support PCI master writes, but it's only apparently some never-released revisions :) > > That's something we should probably think about doing properly: Have a > > list of AGP "issues" (errata ?) bits that are communicated by the AGP > > host driver to the DRM. > > > > At least all the early Apple AGP bridges don't do writes, and I remember > > we have trouble with a few x86 ones as well. There are also issues when > > a single AGP burst crosses a page boundary, and other things like that. > > :( > -- Benjamin Herrenschmidt <[EMAIL PROTECTED]> ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click -- _______________________________________________ Dri-devel mailing list Dri-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/dri-devel
