Comment 32 for bug 363672

[SYSTEM: Ubuntu Jaunty 32-bit, 4GB RAM, nVidia Quadro FX 770M -- 512MB ]

Hi again all,

after some research I'm wondering whether I might be dealing with two problems,
both fixable by tampering with /proc/mtrr :

(1) the way main memory is allocated to my graphics card:

     http://ubuntuforums.org/showthread.php?t=1130582 (Intel specific, but may apply for other
     manufacturers)

     Look at the MTRR stuff specifically. A technique for fixing /proc/mtrr settings
     is found here (i.e. using "write-combining"):

     https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-intel/+bug/314928

(2) following material above, I found that the memory reported by lspci is different
     from what I see in /proc/mtrr (256MB versus 512MB). Could this be related to my problems?

---------------------------
# lspci -vvnn | less
        01:00.0 VGA compatible controller: nVidia Corporation Quadro FX 770M (rev a1)
        Subsystem: Dell Device 0250
        Flags: bus master, fast devsel, latency 0, IRQ 16
        Memory at f5000000 (32-bit, non-prefetchable) [size=16M]
        Memory at e0000000 (64-bit, prefetchable) [size=256M]
        Memory at f2000000 (64-bit, non-prefetchable) [size=32M]
        I/O ports at df00 [size=128]
        [virtual] Expansion ROM at f4000000 [disabled] [size=512K]
        Capabilities: <access denied>
        Kernel driver in use: nvidia
        Kernel modules: nvidia, nvidiafb
---------------------------

# cat /proc/mtrr
reg00: base=0x000000000 ( 0MB), size=32768MB, count=1: write-back
reg01: base=0x0e0000000 ( 3584MB), size= 512MB, count=1: uncachable