I have a Dell Precision Workstation 450 with a Quadro 4 900 XGL and Redhat 8.0, and I have also seen the E7505 problem.
Initially, I saw the error messages in dmesg and just ignored it. My system did work and even claimed to use NVAGP.
But every few days my machine would freeze and without any other knowledge, I'm blaming the problem on AGP. So I added the following line to /etc/modules.conf:
options agpgart agp_try_unsupported=1
and the error messages in dmesg went away. I only made this change this morning, so I'm not sure how this change will effect stability.
I would have used the NVAGP right off of the bat except for two things.
First, the README.txt says nothing about the E7505 chipset being supported. (Although Andy says that NVAGP "should" support this chipset earlier in this thread.)
Second, while I think that AGPGART is a module, and not statically compiled in my kernel, I don't know how to prevent it from being loaded at boot-time.
Is the E7505 officially supported by NVAGP?
If so, shouldn't the README.txt be updated?
How do I prevent AGPGART from being loaded at boot-time?
Once I prevent AGPGART from being loaded at boot-time, will the NvAGP option in the XF86Config file handle the loading of AGPGART (if I set NvAGP=2)? If not, what should I do?
If I just want to use NVAGP (and set NvAGP = 1), do I have to do anything to make sure the NVAGP module gets loaded?
In answering questions, if possible, please provide explicit instructions on which commands to run and/or files to edit.