On Mon, Dec 10, 2001 at 12:39:57AM -0800, Philip Brown wrote:
> So I'm looking through the AGP stuff, still learning...
> and it seems that there's a whole lot of redundancy in the current API.
> 
> If I'm understanding the sequence properly, generally programs do the
> following:
> 1. open /dev/agpgart
> 2. ioctl(ACQUIRE)
> 3. ioctl(INFO)     to determine amountof memory for AGP
> 4. mmap the device
> 5. ioctl(SETUP)    to set the AGP mode
> 6. ioctl(ALLOCATE) a chunk o memory, specifying offset in aperture
> 7. ioctl(BIND)     that same chunk o memory
> 
> The allocate and bind parts seem to be useless, since the program has
> to call mmap() anyway [right?] 

Every time you update the GATT, you have to flush the cache and/or
TLBs.  This is expensive.  Therefore, you allocate and bind the pages
you'll use, and mmap() just returns the right pages when needed.

-- Gareth

_______________________________________________
Dri-devel mailing list
[EMAIL PROTECTED]
https://lists.sourceforge.net/lists/listinfo/dri-devel

Reply via email to