Bug#761062: Upgrading from 304.117-1 to 340.32-1 with older graphics card leaves system without X Windows

[Vincent Cheng]

Hi Marvin,

On Tue, Sep 9, 2014 at 1:22 PM, Marvin Renich <mrvn at renich.org> wrote:
> Source: nvidia-graphics-drivers
> Version: 340.32-1
> Severity: important
>
> On a machine with a graphics card supported by version 304, but
> relegated to the legacy packages for version 340, upgrading the
> nvidia-kernel-dkms and nvidia-driver packages leaves the system with an
> unusable X Windows system.
>
> The preinst script should determine if the hardware was supported by the
> old version of the package but not the new version, and give the
> sysadmin an opportunity to fail the upgrade, with an appropriate
> explanation.

Most of the heavy lifting can be done with nvidia-detect; I would've
assumed that there was already a debconf prompt provided by
nvidia-graphics-drivers/nvidia-support, but I guess there isn't? In
any case, patches welcome.

I'd like to point out that the various nvidia packages are (supposed
to be) co-installable, letting you pick what driver series to use at
runtime rather than during package installation (and the kernel
modules are patched so that they're versioned as well), so I don't
think we should forcefully fail package installation attempts of
nvidia drivers that aren't compatible with the user's hardware. Again,
probably a debconf prompt invoking nvidia-detect at some point would
be appropriate.

Regards,
Vincent