Cannot load AGPGART

[arise]

Redhat 8.0
GF4 Ti4200
Asus P4S533 (Sis645DX)
Drivers 31.23 from SRPMs

GFX card is recognized as 4x 2x 1x capable:

Model: GeForce4 Ti 4200
IRQ: 11
Video BIOS: 04.25.00.30.00
Card Type: AGP
---------------------------------
Fast Writes: Supported
SBA: Supported
AGP Rates: 4x 2x 1x
Registers: 0x1f000217:0x00000000
------------------------------------------

The SIS 645DX looks like it's unknown:

Host Bridge: SiS (unknown)
Fast Writes: Supported
SBA: Supported
AGP Rates: 4x 2x 1x
Registers: 0x1f000217:0x00000000

----------------------

Modprobe, insmode and /etc/modules.conf cannot load the agpgart driver:

/lib/modules/2.4.18-14/kernel/drivers/char/agp/agpgart.o: init_module: No such device
Hint: insmod errors can be caused by incorrect module parameters, including invalid IO or IRQ parameters.
You may find more information in syslog or the output from dmesg
/lib/modules/2.4.18-14/kernel/drivers/char/agp/agpgart.o: insmod /lib/modules/2.4.18-14/kernel/drivers/char/agp/agpgart.o failed
/lib/modules/2.4.18-14/kernel/drivers/char/agp/agpgart.o: insmod agpgart failed


=========================
Help anyone, pls? :)

[arise]

I solved it.
I ran "dmesg" from a terminal, and i saw the kernel messages that told me:

Linux agpgart interface v0.99 (c) Jeff Hartmann
agpgart: Maximum main memory to use for agp memory: 439M
agpgart: Unsupported SiS chipset (device id: 0646), you might want to try agp_tr
y_unsupported=1.
agpgart: no supported devices found.

I did just that:

"modprobe agpgart agp_try_unsupported=1"

...and it loaded just fine ;)

[Soul-Crusher]

Very interesting. If you go into your source tree and edit the agpgart_be.c file in the linux/drivers/char/agp directory, you can add device ID's like this:
{ PCI_DEVICE_ID_SI_740,
PCI_VENDOR_ID_SI,
SIS_GENERIC,
"SiS",
"740",
sis_generic_setup },

It ain't pretty, but it's a more permanent solution. I had to do that on my SiS745 with some older kernels, but the new kernel fixed that. I suppose the latest 645 chipset is even newer than the 2.4.19 kernel?