Graphics card: NVIDIA FX 5200
uname -a: '[...] 3.13.0-30-generic #55~precise1-Ubuntu SMP Fri Jul 4 21:56:07 UTC 2014 i686 i686 i386 GNU/Linux
Yesterday (previous kernel version), my Update Manager popped up to advise of a slew of updates (including one to do with my hardware) available to perform. I accepted them and rebooted.
However, after said boot-up, I found I was no longer able to start a graphical session, not even run X.
It turned out that the updated NVIDIA graphics card module could not be loaded.
dmesg returned this:
nvidia: Unknown symbol acpi_os_wait_events_complete (err 0).
By googling I found a page about this issue with a solution that the section of source code in
nv_acpi.c (it turns out the file on my system is called
nvacpi.c) outputting this error be commented out.
Now, I backed-up the existing
nvacpi.c and got editing, the NVIDIA 'README' on my system advising to do a
make install. But when I rebooted I got the same error.
I ended up commenting out any sections of source code in various related files that had anything to do with ACPI, getting more fundamental errors as a result.
Finally, having failed to fix anything, I purged my system of the NVIDIA driver and X, the system automatically reverting to the nouveau driver, and then re-installed X.
Although most things are working now, this is not really satisfactory as I can't use Blender or Google Earth.
Have I missed a step in re-compiling and installing re the 'nvacpi.c' source file?
There was another NVIDIA help file which mentioned 'diff' and some other commands.