[Open-graphics] HELP: Weird discrepancy between fbZPutImage and memcpy

[Timothy Normand Miller]

On 7/11/07, Zan Lynx <zlynx at acm.org> wrote:
> I bet that it is the MTRR setting.
> Here is the MTRR from a system running an Nvidia card with the nv driver.
> $ cat /proc/mtrr
> reg00: base=0x00000000 (   0MB), size=1024MB: write-back, count=1
> reg01: base=0xf0000000 (3840MB), size=  64MB: write-combining, count=1
>
> This is the line from the X log where it sets it up:
> (==) NV(0): Write-combining range (0xf0000000,0x4000000)
>

Here's what I found deep in x.org:

#if defined(__ia64__) || defined(__arm__) || defined(__s390__)
#ifndef MAP_WRITECOMBINED
#define MAP_WRITECOMBINED 0x00010000
#endif
#ifndef MAP_NONCACHED
#define MAP_NONCACHED 0x00020000
#endif
    if(flags & VIDMEM_FRAMEBUFFER)
        mapflags |= MAP_WRITECOMBINED;
    else
        mapflags |= MAP_NONCACHED;
#endif

This is used on mmap.  I'm going to try it.

-- 
Timothy Normand Miller
http://www.cse.ohio-state.edu/~millerti
Open Graphics Project