On Thu, 17 Mar 2005 18:50:50 -0500 Daniel Phillips <[EMAIL PROTECTED]> wrote:
> Just for reference, how about describing the mga approach here? It uses always indirect DMA for all commands. a DMA transfere looks like this: (Disclaimer: i do not fully understand how the matrox DMA system works. I'm quite sure i missed quite a lot of it) * Set up secondary DMA transfere buffer. * Set up primary DMA buffer to read from the secondary buffer(s). * Write PRIMEND (end of primary buffer) to start transfere. The data written in the primary DMA buffer are register + value pairs which will be loaded into the GPU and then trigger further processing (eg running a 2 stage DMA). The thing that makes it ugly for me is, that every transefer is based either on whole lines or whole pixel. This has the disadvantage that if my user space program has a picture to draw, that i needs to be split at line ends and that the lines are may not cross page boundaries under any circumstances unless the pages are continous. For more information, please have a look at http://attila.kinali.ch/mga_dma-Ville_Syrjala.tar.bz2 which is a kernel module written by Ville SyrjÃlà ([EMAIL PROTECTED]) to test the DMA capabilities of matrox cards. Attila Kinali -- éãåããéãåã _______________________________________________ Open-graphics mailing list [email protected] http://lists.duskglow.com/mailman/listinfo/open-graphics List service provided by Duskglow Consulting, LLC (www.duskglow.com)
