[mythtvnz] 18.04.1 upgrade and old Nvidia drivers

[Stephen Worthington]

I just got the notification today that I can upgrade my MythTV box
from Ubuntu 16.04 to 18.04.1.  But in researching and testing the
upgrade, I have come across a serious problem for boxes that are using
old Nvidia drivers, like my mother's.  Her box needs the Nvidia 304
series drivers, which are no longer supported by Nvidia:

https://nvidia.custhelp.com/app/answers/detail/a_id/3142/~/support-timeframes-for-unix-legacy-gpu-releases

As a result of the support having been dropped, the 304 drivers
apparently do not compile against the 4.15 series kernels used in
18.04.1, and as a result of that, Ubuntu has dropped the Nvidia 304
driver packages.  There are web pages that tell you how to install the
304 drivers by downloading them from Nvidia and patching them before
installing.  I have not tried this yet, and it will certainly
complicate doing kernel updates, unless I can work out how to automate
it using DKMS.

The implications for doing an 18.04.1 upgrade are also nasty.  You
will probably need to remove the Nvidia drivers and switch back to the
Nouveau drivers before doing the upgrade.  The Nouveau drivers have
now got VDPAU support, but I have not tried using them with MythTV.
Last I heard, a couple of years ago, Nouveau+VDPAU did not work as
well with MythTV as it should.  But it would be worth trying again now
to see if it was OK - if so, that might be the best path forwards for
MythTV boxes with old Nvidia cards.

This same problem will hit users of Nvidia cards using the 340 drivers
(such as my GT 220 cards) at the end of 2019 when Nvidia stops support
for them also.  Nvidia seems to be thinking that all its older GPUs
are no longer being used.  That may well be the case for video cards
with fans, but my fanless ones, and my mother's motherboard builtin
GPU, are still going just fine after more than 8 years 24/7.