Hi Chris! > > I have a question about "what if physical memory is fragmented"? > > The AGIPIOC_ALLOC call returns a 'physical' address. > > This implies that the ALLOC is a single contiguous chunk of physical > > memory. Right? > > > > However, I cant imagine that it is easy to guarantee 64 megs of contiguous > > physical RAM allocation. So something seems wrong with my assumption. > > AGP memory is not allocated contiguously (check the calls to agp_bridge. > agp_alloc_page in agp_allocate_memory). > > However, it does look like AGPIOC_ALLOCATE is broken. It only returns > the ->physical field of the resulting agp_memory structure. It doesn't > even look like this field is set for any chipsets other than the i810 > and i830.
That's because it's not necessary. The user can only get the physical pointer if he/she does an ALLOC with type > 0 which is a chip specific ALLOC and it is up to the driver to implement these types or not. > Is /dev/agpgart even supposed to work on Linux? I don't think any > programs use it, and the rest of the kernel used the backend interfaces > directly. It's possible that the frontend has fallen out of sync with > the back. Can anyone here confirm or refute this? Of course it's used. It essential for some X drivers such as i8xx series chips. There is nothing wrong with the frontend either. -- Regards Abraham Those who educate children well are more to be honored than parents, for these only gave life, those the art of living well. -- Aristotle __________________________________________________________ Abraham vd Merwe - 2d3D, Inc. Device Driver Development, Outsourcing, Embedded Systems Cell: +27 82 565 4451 Snailmail: Tel: +27 21 761 7549 Block C, Antree Park Fax: +27 21 761 7648 Doncaster Road Email: [EMAIL PROTECTED] Kenilworth, 7700 Http: http://www.2d3d.com South Africa
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