[elrepo] RE driver update incompatibility issue

[Phil Perry]

On 29/01/13 19:54, Nicolas Thierry-Mieg wrote:
> Le 28/01/2013 23:52, Nux! a écrit :
>> On 28.01.2013 21:26, Lamar Owen wrote:
>>> The pipe-dream, and a 'better than Windows' experience, is a single
>>> package set that covers all legacy versions plus the current version
>>> and leverages udev to load the right bits at boot time. I have no
>>> clue how difficult that would be to implement, other than it's likely
>>> to be pretty hard.
>>>
>>> As I say, I'm not complaining about the status quo; I'm very grateful
>>> for all the work that you do and have done in just getting us the bits
>>> packaged, and packaged very well indeed, IMO.
>>
>> Lamar's idea is quite neat! +1
>
> indeed that's a very cool idea.
>

I'll reply to this email first as it's quicker to do than replying to 
Lamar's post (but I'll get to that!)

> one downside though, it means release a new version of the unified
> nvidia package every time any one of the driver versions gets an update.
> So whatever version you actually use, if you stay up to date you'll
> download and install the new package every time.
> And that will be a massive download... not a problem if you have a fast
> network, but for some users this may be painful. Maybe also for the
> elrepo infrastructure (don't know how developed the mirror system is).
>
> Not saying it's a show stopper but it might be worth considering.

I don't actually think it would be too bad. Updates to legacy versions 
are not that frequent, and often the changelogs indicate the updates 
aren't relevant to RHEL users anyway. For example, nvidia may backport 
support for a newer version of Xorg into an old legacy driver, which may 
be useful for Fedora users but is often irrelevant for us if our version 
of Xorg is fixed or lagging behind. Thus there's often no need for us to 
roll out legacy updates.

>
> Another thing: if all kmods are installed, can you make the kernel load
> the correct one?

My initial thought would be to install all 4 modules in the form of 
nvidia-current.ko, nvidia-304.ko etc, and then to use a script to detect 
the current hardware, select the correct driver and copy that driver 
into place, and finally running depmod. The script could be run during 
package installation and then dropped in place (something like 
/usr/bin/nvidia-select.sh) so the user could manually run it at any time 
should they update their hardware etc.

So to answer your question in the way it is worded, the kernel will 
always load the correct one as that will be the only one available - the 
trick is to ensure it is indeed the 'correct' one that is available.