On Tue, Dec 28, 2004 at 09:10:12AM +0100, Thomas Hellstr�m wrote: > Vladimir Dergachev wrote: > > Can someone more knowledgable explain to me how to properly access AGP > >space from within Mesa driver ?
> This has just been implemented in the Unichrome driver, and I'm not sure > wether it's the best or most appopriate way to do it but it works as > follows: > > 1. The Mesa driver fills a "malloced" system memory buffer with vertex data. > 2. The Mesa driver then calls the DRM through a via-specific IOCTL. > (via_ioctl.c) > 3. The via drm copies the buffer to another buffer in kernel system > memory ( static storage ), (via_dma.c) > 4. The via drm verifies the content of the buffer to reject buffers that > contain commands that are considered harmful. (via_verifier.c) > 5. The buffer is copied to AGP space, and the engine pointers are > updated. (via_dma.c) > > The reason for 3. is that running the verifier directly on AGP memory is > very slow. Is there some reason you can't run the verifier on the user-space buffers? Copying the data twice seems terribly wasteful. Enlightenment requested :) Phil -- http://www.kantaka.co.uk/ .oOo. public key: http://www.kantaka.co.uk/gpg.txt ------------------------------------------------------- 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://productguide.itmanagersjournal.com/ -- _______________________________________________ Dri-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/dri-devel
