concerning X freeze recurring (historical background)

[Dax Kelson]

On Thu, 2006-10-12 at 18:54 -0500, Dax Kelson wrote:

> Sorry I don't have more details but I'm waiting for my sushi to arrive and 
> I just have my Treo. I filed a bugzilla bug at the time where the 
> commentary and details are. 

The problem with lockups with ATI video cards, often on Thinkpads, has
been around for a very long time (at least Nov of 2005). See:

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=174646
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=182196

When the kernel radeon drm module loads -- even if DRI isn't being used
-- makes the card unhappy and you get a system hang at some point (few
minutes to hours).

When FC5 shipped this problem was solved with the
linux-2.6-drm-cripple-r300.patch applied to the 2.6.16 kernel, initially
the patch worked by removing matches for specific PCI vendor and device
ids. When the problem was discovered to very widespread the patch was
reworked to the following:

+int radeon_allow_r300;
+
+MODULE_PARM_DESC(allow_r300, "Allow DRI on Radeon R300 and later cards");
+module_param_named(allow_r300, radeon_allow_r300, int, 0444);
+

+ if (!radeon_allow_r300 && (flags & CHIP_FAMILY_MASK) >= CHIP_R300) {
+       printk(KERN_NOTICE "Avoiding DRI on Radeon R300+. Use 'allow_r300=1' module option to override\n");
+       return DRM_ERR(ENXIO);
+ }
+

When FC5 re-based to the 2.6.17 kernel (in June), this patch was dropped
and many people started having lockups. See bug:

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=197145

I discovered this patch was dropped after doing a lot of work including
a git bisect from 2.6.18-rc1 to 2.6.16 and found that the problem
existed in all the stock kernels (as they didn't have the above patch).

On July 9th I filed a bug requesting to have the patch re-added to the
Fedora kernel.

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=198121

I was told that if we just kept on papering over the legitimate bug then
it would never get fixed. Seems reasonable, however, I need a system
that doesn't lockup frequently.

The two workarounds are:

* Re-apply linux-2.6-drm-cripple-r300.patch
* Use the proprietary ATI fglrx driver

Dax Kelson
Guru Labs