Question on multi-head Dapper->Hardy upgrades

[Michael Vogt]

On Wed, Feb 06, 2008 at 12:33:15PM -0800, Bryce Harrington wrote:
> Hi mvo,
Hi Bryce,
 
> What is our position on supporting upgrades of users with xorg.conf's
> that have Xinerama-based dual-head configurations to Hardy (where
> Xinerama is now deprecated)?  Is this an upgrade path that you are
> testing, or one we will not be supporting?  If the latter, what should
> we communicate to users about this?

Ideally it should be possible to emulate a Xinerama setup with
xrandr. But this is upstream land of course and if that is not done,
then we don't have the resources to do it ourself (or is there a
technical reason why this couldn't be done?).

What will happen for users with xinerama setups if they upgrade? Will
they just be ignored and only one monitor comes up? Or will they crash
in some way?  I think its acceptable if we come up with a single head
only and offer a quick and simple way to active the second head again
with a gui for Xrandr. We could use
e.g. https://wiki.ubuntu.com/InteractiveUpgradeHooks for this and
install one if we detect a Xinerama setup. It would have a "Command:
xrandr-config" (or whatever tool we use to configure the display) line
so that the user just has to click to get the config tool.
 
> (This also touches on a more general question - due to the wide
> variances that can exist in Dapper-era xorg.conf configurations, I think
> it may be extremely hard to assure their old xorg.conf's will upgrade
> problem-free.  Should we set aside their Dapper xorg.conf on upgrade and
> generate a new one that uses Xorg autodetection?)

I think doing something like this is problematic. Users will have
configured their xorg.conf in way that are not auto-detectable, some
may prefer a lower resolution even if their monitor supports a higher
one. Some may have setup their input device in a special way (stuff
like "EmulateWheel" "true", "XkbOptions"    "ctrl:nocaps", etc).
What about cases where we have two valid drivers (ati and fglrx, nv
and nvidia). People expect that we keep that setting.

What sort of trouble do you expect? If its only a small number of
system, I would prefer to re-generate a xorg.conf for them instead of
re-generating them for everyone (in failsafe X mode as a option
maybe?). We have to make sure of course that customizing the xorg.conf
for common options is easy enough and that our failsafe X stuff is
working.

Cheers,
 Michael