Kernel crash on Asus A7N8X-X

[Frédéric PRACA]

Hello dear hackers,
I own a Asus A7N8X-X motherboard (NForce2 chipset) with a Radeon 9600 video
card. After upgrading from 6.3 to 7.0, I launched xorg which crashed the kernel.
After looking in the kernel core dump, I found that the agp_nvidia_flush_tlb
function of /usr/src/sys/pci/agp_nvidia.c crashed on the line 377. The loop
fails from the beginning (when i==0). I commented out the two last loops and it
seems to work now but as I didn't understand what is this code for, I'd like to
have some explanation about it and want to know if someone got the same problem.

Fred