Red Hat Bugzilla – Bug 11240
agpgart module kills xfree86/kernel after unload/reload
Last modified: 2008-05-01 11:37:55 EDT
On an i810-based motherboard (Intel CA810EAL), the agpgart kernel module generally works all right with XFree86 3.3.6. However, if the kernel module is auto-loaded (by associating char-minor-175 in /etc/conf.modules), only the first few X sessions work. After a multi-hour break of the machine sitting in console mode, a subsequent X startup either freezes the kernel/machine completely, or prints a kernel Oops. Some experimentation suggests that this may be because the agpgart driver is not capable of being safely unloaded and reloaded. If there is not much time between consecutive X sessions, or if the agpgart driver is loaded by hand with cleanmod disabled, things don't break. To reproduce the problem: * get a kernel RPM with the agpgart module in it * get an i810-based motherboard * configure enough stuff to start X correctly at least once * run X, then kill the server * optional: run X again right away to confirm that things are still okay * rmmod agpgart * insmod agpgart * run X again. Observer machine crash or hang or kernel Oops. (Before the last step, it would be prudent to sync ; umount unneded file systems.)
On a motherboard with a VIA MVP3 chipset running 2.2.14-12, agpgart finds the AGP aperture at 0xe8000000 the first time it is loaded, and GLX works well. However, if it's unloaded and reloaded, agpgart finds the aperture at 0x00000000 (and starting X reboots the machine instantly.) (This is easily reproducible on 2.4 as well.)
Is this problem still reproduceable in whatever version of RHL you're using currently, with all updates applied?
This works on 7.2. I believe Alan Cox fixed this sometime during the beta cycle for 7.1
Thanks, closing bug report.