After upgrading from kernel-2.6.29-gentoo-r5 to kernel-2.6.30-gentoo-r4, composite effect with KDE 4.3 stopped working. Kernel config is exactly same. An error is logged: Aug 4 21:38:57 machine NVRM: CPU does not support the PAT, falling back to MTRRs. Reproducible: Always Steps to Reproduce: 1. Install kernel-2.6.29-gentoo-r5 with # CONFIG_X86_PAT is not set 2. Install KDE 4.3. Enable desktop effect (composite), cube emulation. 3. Install x11-drivers/nvidia-drivers-180.60 4. Upgrade to kernel-2.6.30-gentoo-r4 Actual Results: Desktop effect (composite) with Kwin stops working. Expected Results: It should work. This thread provides a patch that works with NVIDIA-driver-185.18. But not with 180.60. http://www.nvnews.net/vbulletin/showthread.php?t=133112&page=2
This bug hit me on my dell d820 laptop (Quadro NVS 110M/GeForce Go 7300 as reported by lspci) Two desktops with newer nvidia cards (one a 8800, one a GTS250) were unaffected.
The patch indicated in that forum does not apply to 180.60, but its quite simple (they just disabled a hunk of code with an #if 0/#endif) I made a similar patch on the 180.60 driver. You can do this: 1. ebuild /usr/portage/x11-drivers/nvidia-drivers/nvidia-drivers-180.60.ebuild unpack 2. mv 180.60.patch /var/tmp/portage/x11-drivers/nvidia-drivers-180.60/work/NVIDIA-Linux-x86-180.60-pkg0/usr/src/nv 3. cd /var/tmp/portage/x11-drivers/nvidia-drivers-180.60/work/NVIDIA-Linux-x86-180.60-pkg0/usr/src/nv 4. patch -p0 < 180.60.patch 5. ebuild /usr/portage/x11-drivers/nvidia-drivers/nvidia-drivers-180.60.ebuild install 6. ebuild /usr/portage/x11-drivers/nvidia-drivers/nvidia-drivers-180.60.ebuild merge 7. ebuild /usr/portage/x11-drivers/nvidia-drivers/nvidia-drivers-180.60.ebuild clean PLEASE NOTE: I don't believe this is a fix, rather than a side step, but if you simply must run the 2.6.30 kernel with this problem, this will get around it.
Created attachment 200427 [details, diff] NVidia's hack-around patch adapted for the 180.60 driver I don't believe this is a true fix, its just what Nvidia suggested someone try to get around the bug . A proper fix will likely be a combination of the next driver release or kernel release
Confirm this workaround patch fixed the issue.
It seems that this patch is no longer needed w the 190.42 release candidate driver. See post #59 in the nvnews forum originally linked for more info if you like.
with the 190.42 nvidia driver and Xorg 7.4, kernel 2.6.31, I have to disable composite in KDE4.3.4 as I get X to lock (have to ssh to the machine and "kill -9 <X-pid>" and then restart xdm. Using kernel 2.6.32 it will instead of lock X, crash the whole system. Have to say I haven't tried a similar hack. Would also like to test the new beta driver 195.22, but didn't manage to build it when I made a new ebuild by renameing the latest one.
Unfortunately this bug has gotten stale due to slipping between the cracks. Please retest with the latest KDE, latest X and latest nvidia-drivers and all should be well.
