On 2014-11-06, at 0:36, Konstantin Olchanski <[log in to unmask]> wrote:

> A few days ago an updated linux kernel and updated xorg packages were
> pushed into the SL6 updates. These updates are automatically installed
> by the default yum configuration of SL6.5.
> 
> Unfortunately these updates are incompatible with pre-installed X11 video
> drivers for NVIDIA (GeForce 210) and AMD/ATI (AMD E-350/E-450 and socket AM1
> on-board video) from ELREPO.
> 
> These are the ELREPO kmod-fglrx and kmod-nvidia packages.
> 
> So all computers with these video cards promptly broke.
> 
> This incompatibility seems to be well known to the perpetrators (X.org API change, leading to crash of Xorg).
> 
> I think such a disruptive update should have been announced a little
> bit more widely and maybe some technical solution could have been implemented
> to avoid breaking X11 outright (i.e. refuse to install new X.org packages
> if known-incompatible NVIDIA or AMD/ATI drivers are loaded).
> 
> It looks like corrected drivers are available from ELREPO, but automatic updates
> from ELREPO are normally disabled because they break themselves (newly installed
> package fails to reload the old kernel module resulting in Xorg not starting
> because of mismatch between newly installed userland drivers and old kernel module).
> 
> As end result, what could have been planned scheduled maintenance is now an emergency
> "patch Wednesday" with many computers requiring reboot and many end users disturbed.
> 
> I have to fix about 6 computers with AMD/ATI drivers and only (what?) 20 computers with NVIDIA drivers.
> 
> Please have a nice day.

I'd recommend subscribing -devel - where this batch of updates was announced separately when it was provided in testing.

> P.S. To add injury to insult, the super advanced Red Hat kernel module management
> system (dracut) does the super slow (bzip2 -9) rebuilt of initramfs not once,
> but twice - once on install of new driver and second time on removal of old driver.
> What should have taken 5 seconds takes a good 2-3 minutes (/usr/bin/time yum update kmod-nvidia).

To add more fun, the -504 kernel ABI has changes in some agp... interfaces. Affects at least the nvidia-304 legacy driver. The 304xx packages ElRepo has now seem to be compatible with the -504 kernel, and thus are probably incompatible with earlier ones...

-- 
Stephan Wiesand
DESY - DV -
Platanenallee 6
15738 Zeuthen, Germany